[424B5] Tango Therapeutics, Inc. Prospectus Supplement (Debt Securities)

Rhea-AI Filing Summary

Tango Therapeutics (TNGX) launched a primary offering of 21,023,337 shares of common stock and pre-funded warrants to purchase up to 3,226,458 shares, with the warrant shares also covered by this supplement. The offering is priced at $8.66 per share and $8.659 per pre-funded warrant, for a total offering price of $209,999,998, yielding estimated net proceeds of $197,399,805 before expenses.

In a concurrent private placement, Tango agreed to sell 1,732,101 shares at $8.66 per share; those securities are not registered here, and this offering is not conditioned on the PIPE. The company estimates cash, cash equivalents and marketable securities of approximately $152.8 million as of September 30, 2025. Tango intends to use proceeds to advance its pipeline and for general corporate purposes, stating that the combined funds are expected to support operations into 2028. The underwriter expects to deliver the securities on or about October 24, 2025.

Insights

Equity Capital Markets Analyst

Large primary raise with clear pricing; neutral impact.

Tango Therapeutics priced an underwritten offering of common shares and pre-funded warrants, plus a concurrent PIPE. The deal lists per‑security pricing ($8.66/share; $8.659/warrant) and an aggregate offering price of $209,999,998, translating to net proceeds of $197,399,805 before expenses.

The filing states intended uses across the pipeline and general purposes, and notes an estimated cash balance of $152.8 million as of September 30, 2025. A 60‑day lock‑up applies, and an existing ATM facility up to $100.0 million is referenced after lock‑up expiration.

Delivery is expected on or about October 24, 2025. Actual impact depends on execution of clinical plans and holder demand; the document does not specify further milestones beyond these dates.

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Filed Pursuant to Rule 424(b)(5)
Registration Statement No. 333-287202

PROSPECTUS SUPPLEMENT

(to Prospectus dated May 21, 2025)

21,023,337 Shares of Common Stock

Pre-Funded Warrants to Purchase 3,226,458 Shares of Common Stock

We are offering 21,023,337 shares of our common stock, par value $0.001 per share (the “common stock”) and, in lieu of common stock to certain purchasers that so choose, pre-funded warrants (the “pre-funded warrants”) to purchase up to 3,226,458 shares of our common stock, in an underwritten offering to a limited number of purchasers pursuant to this prospectus supplement and the accompanying prospectus. The purchase price of each pre-funded warrant equals the price per share at which shares of common stock are being sold in this offering, minus $0.001, and the exercise price of each pre-funded warrant equals $0.001 per share. This prospectus supplement also relates to the offering of the shares of common stock issuable upon exercise of such pre-funded warrants (the “warrant shares”).

In a concurrent private placement (the “PIPE”), we entered into a securities purchase agreement pursuant to which we are also offering 1,732,101 shares of our common stock to an investor. The PIPE is being conducted pursuant to the exemption provided under Section 4(a)(2) of the Securities Act of 1933, as amended (the “Securities Act”), and, as such, the securities offering thereby are not being registered pursuant to this prospectus supplement and accompanying prospectus. See “Use of Proceeds.” This offering is not conditioned on the closing of the PIPE.

Our common stock is listed on The Nasdaq Global Market (“Nasdaq”) under the symbol “TNGX”. The last sale price as reported on The Nasdaq Global Market on October 22, 2025, was $8.66 per share. There is no established public trading market for the pre-funded warrants, and we do not expect a market to develop. In addition, we do not intend to apply for a listing of the pre-funded warrants on Nasdaq or any other national securities exchange or any other nationally recognized trading system.

Investing in our common stock involves risks. See “Risk Factors” on page S-8 of this prospectus supplement, and under similar headings in other documents filed after the date hereof and incorporated by reference into this prospectus supplement and the accompanying prospectus.

Neither the Securities and Exchange Commission, any state securities commission nor any other regulatory body has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

		Per Share				Pre-Funded Warrant				Total
Offering Price		$	8.6600			$	8.6590			$	209,999,998
Underwriting discount(1)		$	0.5196			$	0.5196			$	12,600,193
Proceeds, before expenses, to us		$	8.1404			$	8.1394			$	197,399,805

⁽¹⁾  We refer you to “Underwriting” beginning on page S-28 of this prospectus supplement for additional information regarding underwriting compensation.

The underwriter expects to deliver the shares of common stock and pre-funded warrants offered pursuant to this prospectus supplement and accompanying prospectus on or about October 24, 2025.

Leerink Partners Cantor

Prospectus Supplement dated October 23, 2025

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TABLE OF CONTENTS

PROSPECTUS SUPPLEMENT

		Page
ABOUT THIS PROSPECTUS SUPPLEMENT			S-1
PROSPECTUS SUPPLEMENT SUMMARY			S-3
THE OFFERING			S-6
RISK FACTORS			S-8
CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS			S-11
USE OF PROCEEDS			S-14
DIVIDEND POLICY			S-15
DILUTION			S-16
DESCRIPTION OF CAPITAL STOCK			S-18
CERTAIN MATERIAL U.S. FEDERAL INCOME TAX CONSIDERATIONS FOR NON-U.S. HOLDERS OF COMMON STOCK			S-22
UNDERWRITING			S-31
LEGAL MATTERS			S-35
EXPERTS			S-35
WHERE YOU CAN FIND MORE INFORMATION			S-35
INCORPORATION BY REFERENCE			S-36

PROSPECTUS

		Page
ABOUT THIS PROSPECTUS			1
RISK FACTORS			2
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS			3
OUR COMPANY			5
USE OF PROCEEDS			6
SECURITIES THAT MAY BE OFFERED			7
DESCRIPTION OF CAPITAL STOCK			8
DESCRIPTION OF DEBT SECURITIES			11
DESCRIPTION OF WARRANTS			17
DESCRIPTION OF UNITS			18
PLAN OF DISTRIBUTION			21
LEGAL MATTERS			24
EXPERTS			24
WHERE YOU CAN FIND MORE INFORMATION			24
INCORPORATION BY REFERENCE			25

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ABOUT THIS PROSPECTUS SUPPLEMENT

This document contains two parts. The first part is this prospectus supplement, which describes the specific terms of this offering of our common stock and pre-funded warrants and also supplements and updates information contained in the accompanying prospectus and the documents incorporated by reference into this prospectus supplement and the accompanying prospectus. The second part is the accompanying prospectus dated May 21, 2025, included in our registration statement on Form S-3 (File No. 333-287202), along with the documents incorporated by reference, which provides more general information, some of which may not apply to this offering. Generally, when we refer to this prospectus, we are referring to both parts of this document combined.

To the extent there is a conflict between the information contained in this prospectus supplement, on the one hand, and the information contained in the accompanying prospectus or in any document incorporated by reference that was filed with the Securities and Exchange Commission, or the SEC, before the date of this prospectus supplement, on the other hand, you should rely on the information contained in this prospectus supplement. If any statement in one of these documents is inconsistent with a statement in another document having a later date—for example, a document incorporated by reference in the accompanying prospectus—the statement in the document having the later date modifies or supersedes the earlier statement.

This prospectus supplement and the accompanying prospectus are part of a “shelf” registration statement that we filed with the SEC. Under the shelf registration process, we may offer from time to time various securities, including our common stock. Such registration statement also includes exhibits that provide more detail on the matters discussed in this prospectus supplement and the accompanying prospectus. You should read this prospectus supplement, the accompanying prospectus, including the information incorporated by reference, the exhibits filed with the SEC, and any free writing prospectus that we have authorized for use in connection with this offering, in their entirety before making an investment decision.

We are offering to sell, and seeking offers to buy, shares of our common stock and pre-funded warrants only in jurisdictions where offers and sales are permitted. For investors outside the United States, we have not done anything that would permit this offering or possession or distribution of this prospectus supplement, the accompanying prospectus and in any free writing prospectus that we have authorized for use in connection with this offering in any jurisdiction where action for that purpose is required, other than in the United States. Persons outside the United States who come into possession of this prospectus supplement, the accompanying prospectus and any free writing prospectus that we have authorized for use in connection with this offering must inform themselves about, and observe any restrictions relating to, the offering of the shares of common stock and pre-funded warrants and the distribution of this prospectus supplement, the accompanying prospectus and any free writing prospectus that we have authorized for use in connection with this offering outside the United States.

You should rely only on the information contained or incorporated by reference in this prospectus supplement and the accompanying prospectus, along with the information contained in any free writing prospectus that we have authorized for use in connection with this offering. We have not, and the underwriter has not, authorized anyone to provide you with different or additional information. If anyone provides you with different or inconsistent information, you should not rely on it. We and the underwriter take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. You should assume that the information appearing in this prospectus supplement, the accompanying prospectus, the documents incorporated by reference in this prospectus supplement and the accompanying prospectus, and in any free writing prospectus that we have authorized for use in connection with this offering is accurate only as of the respective dates of those documents, unless we indicate otherwise. Our business, financial condition, results of operations and prospects may have changed since those dates.

We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference in this prospectus supplement or the accompanying prospectus were made solely for the benefit of the parties to such agreement, including, in some cases, for the

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purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties and covenants were accurate only as of the date when made; therefore, such representations, warranties and covenants should not be relied on as accurate representations of the current state of our affairs.

Unless otherwise indicated or the context suggests otherwise, references in this prospectus supplement and the accompanying prospectus to “Tango Therapeutics,” “Tango,” the “company,” “we,” “us,” and “our,” and similar designations refer to Tango Therapeutics, Inc. and, where appropriate, our consolidated subsidiaries. When we refer to “you,” we mean the potential purchasers of our common stock and pre-funded warrants in this offering.

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PROSPECTUS SUPPLEMENT SUMMARY

This summary highlights certain information about us and this offering contained elsewhere in, or incorporated by reference into, this prospectus supplement and the accompanying prospectus. This summary is not complete and does not contain all of the information that you should consider before deciding whether to invest in our common stock. For a more complete understanding of our company and this offering, we encourage you to read and consider carefully the more detailed information in this prospectus supplement and the accompanying prospectus, including our financial statements and related notes and the other information incorporated by reference into this prospectus supplement and the accompanying prospectus, and the information included in any free writing prospectus that we have authorized for use in connection with this offering, including the information referred to under the heading “Risk Factors” in this prospectus supplement beginning on page S-7 and in the documents incorporated herein by reference.

Company Overview

Tango Therapeutics was founded with a clear mission: to discover the next wave of targeted therapies in oncology by addressing the specific genetic alterations that drive cancer. We develop new drugs directed at tumor suppressor gene loss in defined patient populations with high unmet medical need. Tumor suppressor gene loss remains a largely unaddressed target space specifically because these genetic events cannot be directly targeted. Our novel small molecules are designed to be selectively active in cancer cells with specific genetic alterations, killing those cancer cells while sparing normal cells. We also are extending this target space beyond the classic, cell-autonomous effects of tumor suppressor gene loss to include the discovery of novel targets that reverse tumor suppressor gene mediated immune evasion which prevents the immune system from recognizing and killing cancer cells. We believe our approach will provide the ability to deliver deep, durable target inhibition with favorable tolerability and safety profiles, thus potentially maximizing clinical benefit.

We are currently developing two MTA-cooperative protein arginine methyltransferase 5 (“PRMT5”) inhibitors: vopimetostat (TNG462) for non-central nervous system (“non-CNS”) cancers, including pancreatic and lung cancer, and TNG456, our next-generation, brain-penetrant PRMT5 inhibitor, for central nervous system (“CNS”) cancers, including glioblastoma (“GBM”).

In May 2025, the first patient was treated with TNG456 in the dose escalation portion of the Phase 1/2 clinical trial to evaluate the safety, pharmacokinetics, pharmacodynamics and antitumor activity of TNG456 as a monotherapy. The trial is currently enrolling patients with MTAP-deleted solid tumors, with a focus on GBM. Preclinical data for TNG456 showed favorable potency and MTAP selectivity and sufficient brain penetrance to potentially have meaningful efficacy in GBM.

TNG260 is a first-in-class CoREST inhibitor, which in preclinical studies reversed the immune evasion effect of STK11 loss-of-function mutations. TNG260 had a favorable safety, tolerability and pharmacokinetic profile in dose escalation, and clinical proof-of-mechanism has now been established based on pharmacodynamic data from on-treatment patient biopsies. We are enrolling patients in the dose expansion portion of the Phase 1/2 clinical trial in STK11-mut/RAS WT lung cancer (~10% of lung adenocarcinoma). We plan to provide clinical data for TNG260 in the second half of 2025.

TNG961 is a development candidate targeting HBS1L in FOCAD-deleted solid tumors. FOCAD deletion occurs in 20-40% of all MTAP-deleted cancers. FOCAD deletion is common in NSCLC, occurring in ~5% of these patients. 20-40% of cancers with MTAP deletion have a coincident FOCAD deletion on chromosome 9, and cancers with FOCAD deletion are dependent on HBS1L for mRNA processing, thus protein synthesis. By degrading HBS1L and disrupting the HBS1L/PELO complex, TNG961 causes tumor regression in FOCAD-deleted preclinical models of multiple histologies.

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Recent Developments

Vopimetostat (TNG462) Clinical Update

In October 2025, we reported positive early data from the ongoing Phase 1/2 clinical trial of vopimetostat, demonstrating strong clinical activity across multiple cancer types with a favorable safety and tolerability profile to date. The cut off date for the analysis was September 1, 2025 and included all evaluable patients at active doses (200 mg QD and above) that were enrolled more than 6 months prior to the efficacy analysis.

Across all MTAP-del tumor types, there were 94 tumor evaluable patients. We observed an ORR (objective response rate) of 27% and mPFS (median progression free survival) of 6.4 months. In the 29 patients with 2L (second line) MTAP-deleted pancreatic cancer, mPFS was 7.2 months. In patients with 2L pancreatic cancer that were enrolled more than 6 months prior to the data cutoff and were tumor evaluable (n=8) the ORR was 25%, more than double that observed in historical chemotherapy studies (~10%), supporting the planned initiation of a pivotal trial in this patient population in 2026. In the histology agnostic cohort with 47 evaluable late line patients, we observed a 49% ORR and mPFS of 9.1 months. The histology agnostic cohort excludes pancreatic and lung cancer patients, as those indications were enrolled in separate cohorts and are being developed independently. Sarcoma patients are also excluded from this analysis, as no activity was observed in this indication (ORR 0%), which will not be pursued in future development. As of September 1, 2025, 41 patients with 2L+ lung cancer patients were enrolled in the Phase 1/2 clinical trial at active doses, 12 of whom were enrolled more than 6 months prior to the analysis. Emerging data from the lung cohort are consistent with expectations, and we anticipate providing a safety and efficacy update in 2026. Additionally, vopimetostat demonstrated a favorable safety and tolerability profile with no drug-related dose discontinuations and ~8% dose reduction in patients dosed at 250 mg QD as of the data cut off date. We have FDA agreement on 250 mg QD as the go-forward dose.

In June 2025, the first patient was treated in the combination clinical trial that is evaluating vopimetostat with the of RAS(ON) multi-selective inhibitor, daraxonrasib, and RAS(ON) G12D-selective inhibitor, zoldonrasib (Revolution Medicines). In the first cohort in the trial (n=7), both combinations have been well-tolerated to date and have early signs of activity. We believe the ongoing clinical trial has the potential to support a 1L pancreatic cancer pivotal study in MTAP-del/RAS mut patients.

Concurrent Private Placement

In October 2025, we entered into a securities purchase agreement with an investor for the purchase and sale of 1,732,101 shares of our common stock at $8.66 per share.

The securities purchase agreement contains customary registration rights in respect of the securities to be issued in connection with the PIPE, which provide that, among other things, within thirty calendar days of the closing of the PIPE, we are required to file a registration statement to register for resale the shares purchased in the PIPE. We have also agreed to use our commercially reasonable efforts to have such registration statement declared effective under the Securities Act as soon as practicable after the filing thereof, but no later than the earlier of (i) the five business days after the date on which the Securities and Exchange Commission (the “SEC”) notifies us that it will not review the registration statement or has no further comments and (ii) the sixtieth day after the closing of the PIPE (or the ninetieth day if the SEC reviews such registration statement).

This prospectus supplement and the accompanying prospectus are not an offer to sell or a solicitation of an offer to buy any securities in connection with the PIPE.

Certain Unaudited Preliminary Financial Results

We estimate that our cash, cash equivalents and marketable securities were approximately $152.8 million as of September 30, 2025. The foregoing information is based on preliminary unaudited information and management

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estimates as of and for the quarter ended September 30, 2025, is not a comprehensive statement of our financial results, and is subject to completion of our financial closing procedures. During our financial closing process our estimates can differ materially from our initial estimates presented herein based on our receipt of updated information. See the sections entitled “Risk Factors” and “Cautionary Statement Regarding Forward-Looking Statements” in this prospectus supplement and the documents incorporated by reference herein, for a discussion of certain factors that could result in differences between these preliminary unaudited estimates and the actual results. The preliminary financial data included in this prospectus supplement has been prepared by, and is the responsibility of, our management. PricewaterhouseCoopers LLP has not audited, reviewed, examined, compiled, nor applied agreed-upon procedures with respect to the preliminary financial data. Accordingly, PricewaterhouseCoopers LLP does not express an opinion or any other form of assurance with respect thereto.

Corporate History

We were incorporated under the laws of the State of Delaware on May 21, 2020 under the name BCTG Acquisition Corp., or BCTG, and were incorporated in Delaware in May 2020 as a special purpose acquisition company, formed for the purpose of effecting a merger, capital stock exchange, asset acquisition, stock purchase, reorganization or other similar business combination. On August 10, 2021, we consummated the merger pursuant to the Agreement and Plan of Merger, dated as of April 13, 2021, by and among BCTG, BCTG Merger Sub Inc. and Tango Therapeutics Sub, Inc. Upon the consummation of the merger, we changed our name to Tango Therapeutics, Inc. Our principal corporate office is located at 201 Brookline Avenue, Suite 901, Boston, MA 02215, and our telephone number is (857) 320-4900. Our website address is https://tangotx.com. We do not incorporate the information on or accessible through our website into this prospectus supplement, and you should not consider any information on, or that can be accessed through, our website as part of this prospectus supplement.

We own various U.S. federal trademark applications and unregistered trademarks, including our company name. All other trademarks or trade names referred to in this prospectus supplement are the property of their respective owners. Solely for convenience, the trademarks and trade names in this prospectus supplement are referred to without the ^® and ^™ symbols, but such references should not be construed as any indicator that their respective owners will not assert, to the fullest extent under applicable law, their rights thereto.

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THE OFFERING

Common stock offered by us 21,023,337 shares.

Pre-funded Warrants Offered We are also offering, in lieu of common stock to certain purchasers who so choose, pre-funded warrants to purchase 3,226,458 shares of our common stock. The purchase price of each pre-funded warrant equals the price per share at which the shares of our common stock are being sold in this offering, minus $0.001, and the exercise price of each pre-funded warrant is $0.001 per share. The pre-funded warrants do not expire, and each pre-funded warrant will be exercisable at any time after the date of issuance of such pre-funded warrant, subject to an ownership limitation. See “Description of Pre-Funded Warrants.” This prospectus supplement also relates to the offering of the shares of our common stock issuable upon exercise of the pre-funded warrants.

Concurrent PIPE In a concurrent PIPE, we have entered into a securities purchase agreement pursuant to which we are offering 1,732,101 shares of our common stock to an investor. The PIPE is being conducted pursuant to the exemption provided by Section 4(a)(2) of the Securities Act and, as such, the securities offered thereby are not being registered pursuant to this prospectus supplement and the accompanying prospectus. The gross proceeds of the PIPE are expected to be approximately $15.0 million.

Common stock to be outstanding immediately after this offering and the concurrent PIPE 133,626,687 shares, assuming no exercise of the pre-funded warrants included in this offering.

Use of proceeds We estimate that the net proceeds to us from this offering, after deducting the underwriting discounts and commissions and estimated offering expenses payable by us, will be approximately $197.0 million. This estimate excludes the proceeds, if any, from the exercise of the pre-funded warrants sold in this offering. We also estimate that the net proceeds from the PIPE will be approximately $15.0 million, after deducting estimated PIPE expenses payable to us. We intend to use the net proceeds from this offering to advance our pipeline and for working capital and other general corporate purposes. Based upon our current operating plan, we believe that the net proceeds from this offering and the PIPE, together with our existing cash, cash equivalents and marketable securities, will enable us to fund our operating expenses and capital expenditure requirements into 2028. See “Use of Proceeds” on page S-13 of this prospectus supplement.

Risk factors Investing in our common stock involves a high degree of risk. See “Risk Factors” beginning on page S-7 of this prospectus supplement, as well as “Risk Factors” in the documents incorporated by reference into this prospectus supplement and the accompanying prospectus, for a discussion of factors you should consider carefully before deciding to purchase any shares of our common stock.

Nasdaq Global Market symbol TNGX.

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All information in this prospectus supplement related to the number of shares of our common stock to be outstanding immediately after this offering is based on 110,871,249 shares of our common stock outstanding as of June 30, 2025. The number of shares outstanding as used throughout this prospectus supplement, unless otherwise indicated, excludes:

• 23,729,595 shares of common stock issuable upon the exercise of stock options outstanding as of June 30, 2025, at a weighted average exercise price of $6.52 per share;

• 1,413,613 shares of common stock issuable upon the vesting of restricted stock units as of June 30, 2025;

• 7,480,243 shares of common stock available for future issuance under our 2021 Stock Option and Incentive Plan (the “2021 Plan”) as of June 30, 2025, as well as any automatic increases in the number of shares of common stock reserved for issuance under the 2021 Plan;

• 3,694,805 shares of common stock available for future issuance under our 2021 Employee Stock Purchase Plan (the “ESPP”) as of June 30, 2025, as well as any automatic increases in the number of shares of common stock reserved for issuance under the ESPP;

• 2,041,015 shares of common stock available for future issuance under the 2023 Inducement Plan as of June 30, 2025;

• 256,100 shares of our common stock issuable upon the exercise of stock options granted subsequent to June 30, 2025, through October 22, 2025 at a weighted-average exercise price of $6.63 per share;

• 42,430 shares of our common stock issuable upon the vesting and settlement of restricted stock units granted subsequent to June, 2025, through October 22, 2025; and

• 3,226,458 shares of common stock issuable upon exercise of the pre-funded warrants issued in this offering.

In addition, the number of shares outstanding immediately after this offering does not include shares of common stock that we may offer and sell in the future pursuant to our Open Market Sales Agreement^SM with Jefferies LLC. After the expiration or waiver of the lock-up period applicable to us and described under the section of this prospectus supplement titled “Plan of Distribution,” we may offer and sell shares of our common stock having an aggregate offering price of up to $100.0 million from time to time in “at-the-market” offerings.

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RISK FACTORS

Investing in our common stock involves a high degree of risk. Before making an investment decision, you should carefully consider the risks described in our most recent Annual Report on Form 10-K and subsequent Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, as well as any amendments thereto reflected in subsequent filings with the SEC, each of which are incorporated by reference in this prospectus supplement, and all of the other information in this prospectus supplement, including our financial statements and related notes incorporated by reference herein, and in any free writing prospectus that we have authorized for use in connection with this offering before acquiring any of our common stock. These risks could result in material and adverse impact on our business, financial condition, results of operations and prospects, which could cause the trading price of our common stock to decline, and you could lose part or all of your investment. Additional risks and uncertainties that are not yet identified or that we currently believe to be immaterial may also materially harm our business, financial condition, results of operations and prospects and could result in a complete loss of your investment. The risks discussed below also include forward-looking statements, and our actual results may differ substantially from those discussed in these forward-looking statements. See “Cautionary Statement Regarding Forward-Looking Statements.”

Risks Related to Our Common Stock and this Offering

Historically, our share price has been volatile, and this is likely to continue; purchasers of our securities could incur substantial losses as a result.

Historically, the market price of our common stock has fluctuated significantly, and we expect that this will continue. Purchasers of our securities could incur substantial losses relating to their investment in our shares as a result. The stock market in general has recently experienced volatility that has often been unrelated or disproportionate to the operating performance of particular companies. These broad market fluctuations could result in fluctuations in the price of our common stock, which could cause purchasers of our common stock to incur substantial losses. The market price for our common stock may be influenced by many factors, including:

• the success or failure of competitive products or technologies;

• advancement of our preclinical programs into clinical testing;

• results of clinical trials of our product candidates or those of our competitors;

• regulatory or legal developments in the United States and other countries;

• developments or disputes concerning patent applications, issued patents or other proprietary rights;

• the recruitment or departure of key personnel;

• the level of expenses related to any of our programs and product candidates or preclinical and clinical development programs;

• the results of our efforts to discover, develop, acquire or in-license additional product candidates or products;

• actual or anticipated changes in estimates as to financial results, development timelines or recommendations by securities analysts;

• variations in our financial results or those of companies that are perceived to be similar to us;

• changes in the structure of healthcare payment systems and third-party reimbursement decisions;

• market conditions in the pharmaceutical and biotechnology sectors;

• purchases or sales of our securities by our officers, directors or significant shareholders;

• limited trading volume;

• general economic, industry and market conditions; and

• the use of proceeds from this offering

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Our management will have broad discretion over the use of proceeds from this offering and may not use the proceeds effectively.

Although we currently intend to use the net proceeds from this offering in the manner described in the section titled “Use of Proceeds” in this prospectus supplement, we will have considerable discretion in the application of the net proceeds of this offering. We may use the net proceeds for purposes that do not yield a significant return or any return at all for our stockholders. In addition, pending their use, we may invest the net proceeds from this offering in a manner that does not produce income or that loses value. If we do not invest or apply the net proceeds from this offering in ways that enhance stockholder value, we may fail to achieve expected financial results, which could cause our stock price to decline.

Sales of a substantial number of shares of our common stock in the public market could cause our stock price to fall.

Sales of a substantial number of shares of our common stock in the public market following this offering could cause the market price of our common stock to decline. A substantial majority of the outstanding shares of our common stock are, and the shares of common stock offered hereby will be, freely tradable without restriction or further registration under the Securities Act, unless these shares are owned or purchased by “affiliates” as that term is defined in Rule 144 under the Securities Act. We, along with our directors and executive officers and certain of their affiliates, have agreed that for a period of 60 days after the closing of this offering, subject to specified exceptions, we or they will not offer, sell, contract to sell, pledge or otherwise dispose of, directly or indirectly, any shares of our common stock or securities convertible into or exchangeable or exercisable for any shares of our common stock.

Purchasers in this offering will experience immediate and substantial dilution in the book value of their investment.

Purchasers of our common stock in this offering will experience immediate dilution in the net tangible book value of the common stock purchased in this offering because the price per share of common stock in this offering is substantially higher than the net tangible book value per share of our common stock outstanding immediately after this offering. Our net tangible book value as of June 30, 2025, was approximately $135.0 million, or $1.22 per share of our common stock. If you purchase shares of common stock in this offering, you will suffer immediate and substantial dilution of $6.06 per share with respect to the net tangible book value of the common stock (assuming the no pre-funded warrants are exercised). See “Dilution” in this prospectus supplement for a detailed discussion of the dilution you will incur if you purchase shares in this offering.

If we raise additional capital through the sale of shares of our common stock, convertible securities or debt in the future, your ownership in us could be diluted and restrictions could be imposed on our business.

In addition to this offering, we may issue shares of our common stock or securities convertible into our common stock to raise additional capital in the future. To the extent we issue such securities, our stockholders may experience substantial dilution and the trading price of our common stock could decline. If we obtain funds through a credit facility or through the issuance of debt or preferred securities, such debt or preferred securities could have rights senior to your rights as a common stockholder, which could impair the value of our common stock.

Additionally, in September 2022, we entered into an Open Market Sales Agreement^SM with Jefferies LLC, providing for the offering, issuance and sale by the Company of up to $100 million of our common stock from time to time in “at-the-market” offerings (the “ATM”).

These shares can be freely sold in the public market upon issuance.

Sales of our common stock pursuant to the ATM could result in substantial dilution to the interests of other holders of our common stock. Additionally, the sale of a substantial number of shares of our common stock, or

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the anticipation of such sales, could make it more difficult for us to sell equity or equity-related securities in the future at a time and at a price that we might otherwise wish to effect sales.

There is no public market for the pre-funded warrants being offered by us in this offering.

There is no established public trading market for the pre-funded warrants being sold in this offering, and we do not expect a market to develop. In addition, we do not intend to apply to list the pre-funded warrants on any securities exchange or recognized trading system. Without an active market, the liquidity of the pre-funded warrants will be limited.

Holders of the pre-funded warrants will have no rights as common stockholders until they acquire our Common Stock.

Until you acquire shares of our Common Stock upon exercise of the pre-funded warrants, you will have no rights with respect to our Common Stock issuable upon exercise of the pre-funded warrants, including the right to receive dividend payments, vote or respond to tender offers. Upon exercise of your pre-funded warrants, you will be entitled to exercise the rights of a common stockholder only as to matters for which the record date occurs after the exercise date.

Significant holders or beneficial holders of shares of our Common Stock may not be permitted to exercise the pre-funded warrants that they hold.

A holder (together with its affiliates and other attribution parties) may not exercise any portion of a Pre-Funded Warrant to the extent that after giving effect to such exercise, the holder would own more than 4.99% or 9.99% of our outstanding Common Stock immediately after exercise, which percentage may be changed at the holder’s election to a higher or lower percentage not in excess of 19.99% upon 61 days’ notice to us, subject to the terms of the pre-funded warrants. As a result, you may not be able to exercise your pre-funded warrants for shares of our Common Stock at a time when it would be financially beneficial for you to do so. In such a circumstance, you could seek to sell your pre-funded warrants to realize value, but you may be unable to do so in the absence of an established trading market and due to applicable transfer restrictions.

We will not receive a significant amount or any additional funds upon the exercise of the pre-funded warrants.

Each pre-funded warrant is exercisable for $0.001 per share of common stock underlying such pre-funded warrant, which may be paid by way of a cashless exercise, in which the holder would receive upon such exercise the net number of shares of common stock determined according to the formula set forth in the pre-funded warrant. Accordingly, we will not receive a significant amount of additional funds (if any) upon the exercise of the pre-funded warrants.

If we do not maintain a current and effective registration statement relating to the shares of our common stock issuable upon exercise of the pre-funded warrants, holders will only be able to exercise such pre-funded warrants on a “cashless basis.”

If we do not maintain a current and effective registration statement relating to the shares of our common stock issuable upon exercise of the pre-funded warrants at the time that holders wish to exercise such pre-funded warrants, they will only be able to exercise them on a “cashless basis” provided that an exemption from registration is available. As a result, the number of shares of our common stock that holders will receive upon exercise of the pre-funded warrants will be fewer than it would have been had such holder exercised the warrant for cash, and holders may be limited in their ability to immediately sell shares upon exercise subject to volume or other securities law limitations. Further, if an exemption from registration is not available, holders would not be able to exercise on a cashless basis and would only be able to exercise their pre-funded warrants for cash if a current and effective registration statement relating to the shares of our common stock issuable upon exercise of the pre-funded warrants is available.

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CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein, and any free writing prospectus that we have authorized for use in connection with this offering, contain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Exchange Act of 1934, as amended, or the Exchange Act.

Any statements about our expectations, beliefs, plans, objectives, assumptions or future events or performance are not historical facts and are forward-looking. These statements are often, but are not always, made through the use of words or phrases such as “may,” “will,” “could,” “should,” “expects,” “intends,” “plans,” “anticipates,” “believes,” “estimates,” “predicts,” “projects,” “potential,” “continue,” and similar expressions, or the negative of these terms, or similar expressions. Accordingly, these statements are subject to risks and uncertainties that could cause actual results to differ materially from those expressed in them. Any forward-looking statements are qualified in their entirety by reference to the factors discussed throughout this prospectus supplement, and in particular those factors referenced in the section “Risk Factors.”

This prospectus supplement contains forward-looking statements that relate to future events or our future financial performance, and involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to be materially different from any future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements. Forward-looking statements include, but are not limited to, statements about:

• the initiation, timing, progress, results, and cost of our research and development programs and our current and future preclinical studies and clinical trials and combination clinical trials, including statements regarding the timing of IND filings and acceptance, active enrollment and dosing in clinical trials (including combination clinical trials), future plans for dose expansions and dose escalations, and initiation and completion of studies or clinical trials (including combination trials), plans for filing a registrational trial for vopimetostat in 2026 and the continued enrollment in our vopimetostat monotherapy and combination clinical trials (and related preparatory work for each), plans for the TNG456 clinical trial, and the period during which the results of our clinical trials (including initial and final trial results) will become available (such as the data from the ongoing TNG260 clinical trial, expected in the second half of 2025);

• our ability to discover and develop product candidates efficiently (including the advancement of development candidates on the timelines identified and the ability to identify and contract with clinical trial sites and investigators to use our product candidates in trials);

• our ability and potential (or those of third parties) to manufacture our drug product, drug substance and product candidates successfully for preclinical use, for clinical trials and on a larger scale for commercial use, if approved;

• the ability and willingness of our third-party strategic collaborators to license and to continue research and development activities relating to our development candidates and product candidates;

• our ability to obtain funding for our operations necessary to complete further research, development and commercialization of our product candidates (and that existing cash, cash equivalents and marketable securities will enable us to fund our operating expenses and capital expenditure requirements into 2028);

• our ability to obtain and, if approved, maintain regulatory approval of our product candidates (as well as approval or clearance of screening tests and companion diagnostic tests for our product candidates) and the potential paths to approval our product candidates, including for vopimetostat as a monotherapy or in combination in MTAP-deleted pancreatic and lung cancer;

• our ability to commercialize our products, if approved;

• the pricing and reimbursement of our product candidates, if approved;

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• the implementation of our business model, and strategic plans for our business and product candidates;

• the scope of protection we are able to establish and maintain for intellectual property rights covering our product candidates and our ability to enforce our intellectual property rights;

• estimates of our future expenses, capital requirements, and our need for additional financing;

• the potential benefits of strategic collaboration agreements, our ability to enter into strategic collaborations or arrangements, and our ability to attract collaborators with development, regulatory and commercialization expertise;

• future agreements with third parties in connection with the commercialization of product candidates (if approved) and any other approved products;

• the size and growth potential of the markets for our product candidates, and our ability to serve those markets;

• our financial performance, including the expectation that we will continue to incur operating losses and negative cash flow;

• the rate and degree of market acceptance of our product candidates, if approved;

• regulatory developments in the United States and foreign countries, including product approval requirements and pricing regulations by U.S. regulatory authorities (such as the Centers for Medicare & Medicaid Services) and foreign regulatory authorities;

• our ability to contract with third-party suppliers and manufacturers and their ability to perform adequately;

• our ability (or the ability of third parties with whom we contract) to produce our products or product candidates with advantages in turnaround times or manufacturing cost;

• our ability to deliver the deep, durable target inhibition—with favorable tolerability and safety profiles—necessary to maximize clinical benefit as a result of the unique ability of synthetic lethal targeting to spare normal cells, as well as the success of competing therapies that are or may become available;

• our ability to attract and retain key scientific or management personnel;

• the impact of laws and regulations;

• developments relating to our competitors and industry;

• the impact of trade restrictions (such as sanctions or tariffs); regulatory requirements, legal actions, or enforcement; inflation rates; and inadequate funding for government agencies on our business, financial condition, and results of operations;

• the effect of public health crises on our business operations, including but not limited to our preclinical studies and clinical trials and any future studies or trials;

• the expected benefits of the use of our drugs in patients as single agents and/or in combination, including our belief that TNG456 has sufficient brain penetrance to potentially have meaningful efficacy in glioblastoma;

• the availability of our “at-the-market” program and our ability or inability to secure additional funds through equity financing transaction;

• the issuance and sale of our common stock in the concurrent PIPE;

• general economic and market conditions, including, among others, inflation, interest rates, tax rates economic uncertainty, the actual or perceived failure or financial difficulties of additional financial institutions and economic and trade sanctions, including their effect on our results of operations; and

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• other risks and uncertainties, including those listed under the caption “Risk Factors” in this prospectus supplement and in our Annual Report on Form 10-K for the year ended December 31, 2024 and our most recent Quarterly Reports on Form 10-Q for the quarters ended March 31, 2025 and June 30, 2025.

These forward-looking statements are neither promises nor guarantees of future performance due to a variety of risks and uncertainties, many of which are beyond our control, which could cause actual results to differ materially from those indicated by these forward-looking statements, including, without limitation the risk factors and cautionary statements described in other documents that we file from time to time with the SEC, specifically under “Item 1A: Risk Factors” and elsewhere in our most recent Annual Report on Form 10-K for the period ended December 31, 2024 and our most recent Quarterly Reports on Form 10-Q for the quarters ended March 31, 2025 and June 30, 2025, and our Current Reports on Form 8-K, and in this prospectus supplement under the heading “Risk Factors.”

While we may elect to update forward-looking statements at some point in the future, we assume no obligation to update or revise any forward-looking statements except to the extent required by applicable law.

This prospectus supplement and the documents incorporated by reference also contain estimates, projections and other information concerning our industry, our business, and the markets for certain diseases, including data regarding the estimated size of those markets, and the incidence and prevalence of certain medical conditions. Information that is based on estimates, forecasts, projections, market research or similar methodologies is inherently subject to uncertainties and actual events or circumstances may differ materially from events and circumstances reflected in this information. Unless otherwise expressly stated, we obtained this industry, business, market and other data from reports, research surveys, studies and similar data prepared by market research firms and other third parties, industry, medical and general publications, government data and similar sources.

In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date of this prospectus supplement, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain and you are cautioned not to unduly rely upon these statements.

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USE OF PROCEEDS

We estimate that we will receive net proceeds from this offering of approximately $197.0 million after deducting the underwriting discounts and commissions and estimated offering expenses payable by us. We also estimate that the net proceeds from the PIPE will be approximately $15.0 million, after deducting estimated PIPE expenses payable by us. We will receive nominal proceeds, if any, from the exercise of the pre-funded warrants.

We intend to use the net proceeds from this offering and the PIPE, together with our existing cash, cash equivalents and marketable securities to advance our pipeline and for working capital and other general corporate purposes. Based upon our current operating plan, we believe that the net proceeds from this offering and the PIPE, together with our existing cash, cash equivalents and investments, will enable us to fund our operating expenses and capital expenditure requirements into 2028.

The expected use of the net proceeds from this offering and the PIPE represents our intentions based upon our current plans and business conditions, which could change in the future as our plans and business conditions evolve. The amounts and timing of our actual expenditures will depend on numerous factors, including the factors described under “Risk Factors” in this prospectus supplement, the accompanying prospectus and in the documents incorporated by reference herein, as well as the amount of cash used in our operations. We may find it necessary or advisable to use the net proceeds for other purposes, and we will have broad discretion in the application of the net proceeds. Pending the uses described above, we plan to invest the net proceeds from this offering in short- and intermediate-term, interest-bearing obligations, investment-grade instruments, certificates of deposit or direct or guaranteed obligations of the U.S. government.

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DIVIDEND POLICY

We have never declared or paid cash dividends on our capital stock. We intend to retain all of our future earnings, if any, to finance the growth and development of our business. We do not intend to pay cash dividends to our stockholders in the foreseeable future.

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DILUTION

If you invest in our common stock or pre-funded warrants in this offering, your ownership interest will be diluted to the extent of the difference between the public offering price per share of our common stock or pre-funded warrant in this offering and the as adjusted net tangible book value per share of our common stock immediately after this offering.

The net tangible book value of our common stock as of June 30, 2025 was approximately $135.0 million, or approximately $1.22 per share of common stock based upon 110,871,249 shares outstanding. Net tangible book value per share is equal to our total tangible assets (total assets less intangible assets), less our total liabilities, divided by the total number of shares of common stock outstanding as of June 30, 2025.

Net tangible book value dilution per share to investors participating in this offering represents the difference between the amount per share paid by purchasers of shares of common stock in this offering and the as adjusted net tangible book value per share of common stock immediately after completion of this offering and the concurrent PIPE.

After giving effect to the sale by us of shares of our common stock in this offering and shares of our common stock in the PIPE, at the offering price of $8.66 per share and $8.66 per share, respectively, and pre-funded warrants to purchase shares of common stock at the offering price of $8.659 per pre-funded warrant (which equals the public offering price of the common stock at which shares of our common stock are being sold to the public in this offering less the $0.001 per share exercise price of each such pre-funded warrant) (excluding shares of common stock issuable upon exercise of the pre-funded warrants, any proceeds which may be received upon exercise of the pre-funded warrants or any resulting accounting associated with the exercise of the pre-funded warrants), and after deducting the underwriting discounts and commissions and estimated offering and PIPE expenses payable by us, our as adjusted net tangible book value as of June 30, 2025 would have been approximately $347.0 million, or $2.60 per share of our common stock. This represents an immediate increase in net tangible book value of $1.38 per share to our existing stockholders and an immediate dilution in as adjusted net tangible book value of $6.06 per share to new investors in this offering and the concurrent PIPE.

The following table illustrates this calculation on a per share basis:

Offering price per share						$	8.66
Net tangible book value per share as of June 30, 2025		$	1.22
Increase in net tangible book value per share attributable to this offering and the concurrent PIPE			1.38
As adjusted net tangible book value per share after giving effect to this offering and the concurrent PIPE							2.60
Dilution in net tangible book value per share to new investors in this offering and the concurrent PIPE						$	6.06

Assuming the pre-funded warrants were immediately and fully exercised, this would result in an as adjusted net tangible book value, after giving effect to this offering and warrant exercise, of $2.54 per share. This represents an increase in net tangible book value of $1.32 per share to existing stockholders and dilution in net tangible book value per share of $6.12 to investors participating in this offering.

The information above is based upon 110,871,249 shares of our common stock outstanding as of June 30, 2025. The information above excludes:

• 23,729,595 shares of common stock issuable upon the exercise of stock options outstanding as of June 30, 2025, at a weighted average exercise price of $6.52 per share;

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• 1,413,613 shares of common stock issuable upon the vesting of restricted stock units as of June 30, 2025;

• 7,480,243 shares of common stock available for future issuance under our 2021 Stock Option and Incentive Plan (the “2021 Plan”) as of June 30, 2025, as well as any automatic increases in the number of shares of common stock reserved for issuance under the 2021 Plan;

• 3,694,805 shares of common stock available for future issuance under our 2021 Employee Stock Purchase Plan (the “ESPP”) as of June 30, 2025, as well as any automatic increases in the number of shares of common stock reserved for issuance under the ESPP;

• 2,041,015 shares of common stock available for future issuance under the 2023 Inducement Plan as of June 30, 2025;

• 256,100 shares of our common stock issuable upon the exercise of stock options granted subsequent to June 30, 2025, at a weighted-average exercise price of $6.63 per share;

• 42,430 shares of our common stock issuable upon the vesting and settlement of restricted stock units granted subsequent to June, 2025; and

• 3,226,458 shares of common stock issuable upon exercise of the pre-funded warrants issued in this offering.

In addition, we may choose to raise additional capital in the future through the sale of equity or convertible debt securities due to market conditions or strategic considerations, even if we believe we have sufficient funds for our current or future operating plans. To the extent that any of our outstanding options are exercised, shares of common stock are issued upon the vesting and settlement of our restricted stock units outstanding, new equity awards are granted under our equity incentive plans, additional shares of common stock are issued pursuant to the Open Market Sales Agreement^SM with Jefferies LLC or we otherwise issue additional shares of common stock or other equity or convertible debt securities in the future, there may be further dilution to investors participating in this offering.

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DESCRIPTION OF CAPITAL STOCK

The following description of our common stock and preferred stock, together with the additional information we include in any applicable prospectus supplements, summarizes the material terms and provisions of the common stock and preferred stock that we may offer under this prospectus. The following description of our capital stock does not purport to be complete and is subject to, and qualified in its entirety by, our Second Amended and Restated Certificate of Incorporation, as amended from time to time, or certificate of incorporation, and our Amended and Restated Bylaws, as amended from time to time, or bylaws, which are exhibits to the registration statement of which this prospectus forms a part, and by applicable law. The terms of our common stock and preferred stock may also be affected by Delaware law.

General

Our authorized capital stock consists of Four Hundred Million (400,000,000) shares of common stock, par value $0.001 per share and Ten Million (10,000,000) shares of undesignated preferred stock, par value $0.001 per share.

Common stock

Our certificate of incorporation provides the following with respect to the rights, powers, preferences and privileges of the common stock.

Voting Power. Except as otherwise required by law or as otherwise provided in any certificate of designation for any series of preferred stock, the holders of common stock possess all voting power for the election of Tango’s directors and all other matters requiring stockholder action. Holders of common stock are entitled to one vote per share on matters to be voted on by stockholders.

Dividends. Holders of common stock will be entitled to receive such dividends, if any, as may be declared from time to time by our board of directors in its discretion out of funds legally available therefor. In no event will any stock dividends or stock splits or combinations of stock be declared or made on common stock unless the shares of common stock at the time outstanding are treated equally and identically.

Liquidation, Dissolution and Winding Up. In the event of Tango’s voluntary or involuntary liquidation, dissolution, distribution of assets or winding-up, the holders of the common stock will be entitled to receive an equal amount per share of all of Tango’s assets of whatever kind available for distribution to stockholders, after the rights of the holders of the preferred stock have been satisfied.

Preemptive or Other Rights. Our common stock has no preemptive rights, conversion rights or other subscription rights or redemption or sinking fund provisions.

Listing of Securities

Our common stock is listed on the Nasdaq Global Market under the symbol “TNGX”.

Transfer Agent

The transfer agent for our common stock is Computershare Trust Company, N.A.

Preferred stock

Our board of directors will have the authority, without further action by our stockholders, to issue up to 10,000,000 shares of preferred stock in one or more series and to fix the rights, preferences, privileges and

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restrictions thereof. These rights, preferences and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences, sinking fund terms and the number of shares constituting, or the designation of, such series, any or all of which may be greater than the rights of common stock. The issuance of our preferred stock could adversely affect the voting power of holders of common stock and the likelihood that such holders will receive dividend payments and payments upon our liquidation. In addition, the issuance of preferred stock could have the effect of delaying, deferring or preventing a change in control of our company or other corporate action. No shares of convertible preferred stock are outstanding, and we have no present plan to issue any shares of convertible preferred stock.

Registration Rights

Certain of our stockholders (“Holders”) hold registration rights pursuant to an amended and restated registration and stockholder rights agreement (the “Amended and Restated Registration and Stockholder Rights Agreement”).

Stockholders holding a majority-in-interest of such registrable securities are entitled to make a written demand for registration under the Securities Act of 1933, as amended (the “Securities Act”), of all or part of their registrable securities.

In particular, the Amended and Restated Registration and Stockholder Rights Agreement provides for the following registration rights:

• Shelf registration/demand registration rights. At any time and from time to time when an effective shelf registration statement is on file with the SEC, a Holder may request to sell all or any portion of such Holder’s registrable securities by means of an underwritten takedown off of the shelf registration statement, except that we are only obligated to effect such underwritten shelf takedown if such offering will include registrable securities proposed to be sold by the requesting Holder, either individually or together with other requesting Holders, with a total offering price reasonably expected to exceed, in the aggregate, $20.0 million. Additionally, we are not required to effect more than one underwritten shelf takedown in any six-month period.

• Piggyback registration rights. Subject to exceptions for certain offerings and registration statements, if at any time, we propose to file a registration statement under the Securities Act, in connection with an offering of our equity securities or securities or other obligations exercisable or exchangeable for, or convertible into, our equity securities, either for our own account or for the account of other stockholders, the Holders are entitled to include their registrable securities in such registration statement.

• Indemnification. The Amended and Restated Registration and Stockholder Rights Agreement contains customary cross-indemnification provisions, under which we are obligated to indemnify Holders of registrable securities in the event of material misstatements or omissions in the registration statement attributable to us, and Holders of registrable securities are obligated to indemnify us for material misstatements or omissions attributable to them.

Expiration of Registration Rights

The registration rights granted under the Amended and Restated Registration and Stockholder Rights Agreement will terminate on the earlier of (i) the 10th anniversary of the date of the agreement and (ii) with respect to any Holder, on the date that such Holder no longer holds any Registrable Securities.

Anti-Takeover effects of our certificate of incorporation and bylaws and Delaware law

Certificate of Incorporation and Bylaws

Our certificate of incorporation and bylaws include a number of provisions that may have the effect of delaying, deferring or preventing another party from acquiring control of us and encouraging persons considering

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unsolicited tender offers or other unilateral takeover proposals to negotiate with our board of directors rather than pursue non-negotiated takeover attempts. These provisions include the items described below:

• permit our board of directors to issue up to 10,000,000 shares of preferred stock, with any rights, preferences and privileges as they may designate, including the right to approve an acquisition or other change of control;

• provide that the authorized number of directors may be changed only by resolution of our board of directors;

• provide that, subject to the rights of any series of preferred stock to elect directors, directors may be removed only with cause by the holders of at least two thirds (2/3) of all of our then-outstanding shares of the capital stock entitled to vote at an election of directors;

• provide that, subject to the rights of any series of preferred stock to fill director vacancies, all director vacancies, including newly created directorships, may, except as otherwise required by law, be filled by the affirmative vote of a majority of directors then in office, even if less than a quorum;

• provide that stockholders seeking to present proposals before a meeting of stockholders or to nominate candidates for election as directors at a meeting of stockholders must provide advance notice in writing, and also specify requirements as to the form and content of a stockholder’s notice;

• provide that special meetings of our stockholders may be called by our board of directors pursuant to a resolution adopted by a majority of the total number of directors then in office;

• provide that our board of directors will be divided into three classes of directors, with the directors serving three-year terms, therefore making it more difficult for stockholders to change the composition of our board of directors;

• provide that any amendment of our certificate of incorporation must first be approved by a majority of our board of directors, and if required by law or our certificate of incorporation, must thereafter be approved by a majority of the outstanding shares entitled to vote on the amendment and a majority of the outstanding shares of each class entitled to vote thereon as a class, except that the amendment of the provisions relating to stockholder action, board composition, limitation of liability and certificate of incorporation must be approved by not less than two-thirds of the outstanding shares entitled to vote on the amendment, and not less than two-thirds of the outstanding shares of each class entitled to vote thereon as a class;

• our Bylaws may be amended by the affirmative vote of a majority of the directors then in office, subject to any limitations set forth by law or in the bylaws; and may also be amended by the affirmative vote of 75% of the outstanding shares entitled to vote on the amendment; provided, however, if our board of directors recommends such amendment to be voted on at a meeting of the stockholders, such amendment only requires the affirmative vote of the majority of the outstanding shares entitled to vote on such amendment and

• not provide for cumulative voting rights, therefore allowing the holders of a majority of the shares of common stock entitled to vote in any election of directors to elect all of the directors standing for election, if they should so choose.

Delaware Anti-Takeover Law

Tango has opted out of Section 203 of the Delaware General Corporation Law (the “DGCL”). Section 203 of the DGCL prohibits a Delaware corporation from engaging in a “business combination” with an “interested stockholder” (i.e. a stockholder owning 15% or more of company’s voting stock) for three years following the time that the “interested stockholder” becomes such, subject to certain exceptions.

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Exclusive Jurisdiction of Certain Actions

Our bylaws require, to the fullest extent permitted by law, unless we consent in writing to the selection of an alternative forum, that derivative actions brought in the name of Tango, actions against any current or former directors, officers and employees for breach of fiduciary duty, actions asserting a claim arising pursuant to any provision of the DGCL or our certificate of incorporation or our bylaws, actions to interpret, apply, enforce or determine the validity of our certificate of incorporation or our bylaws and actions asserting a claim governed by the internal affairs doctrine may be brought only in the Court of Chancery in the State of Delaware (the “Delaware Forum Provision”). The Delaware Forum Provision will not apply to any causes of action arising under the Securities Act and the Securities Exchange Act of 1934. Our bylaws further provide that unless we consent in writing to the selection of an alternative forum, the federal district courts of the United States shall be the sole and exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act. We refer to such provision as the Federal Forum Provision. Our bylaws provide that any person or entity purchasing or otherwise acquiring any interest in shares of our capital stock is deemed to have notice of and consented to the Delaware Forum Provision and the Federal Forum Provision; provided, however, that stockholders cannot and will not be deemed to have waived our compliance with the U.S. federal securities laws and the rules and regulations thereunder.

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CERTAIN MATERIAL U.S. FEDERAL INCOME TAX CONSIDERATIONS FOR NON-U.S. HOLDERS

The following summary describes the material U.S. federal income tax considerations of the acquisition, ownership and disposition of our common stock and pre-funded warrants acquired in this offering. This discussion does not address all aspects of U.S. federal income taxes, does not discuss the potential application of any alternative minimum tax or Medicare Contribution tax on net investment income, or the special tax accounting rules under Section 451(b) of the Internal Revenue Code, or the Code, and does not address state or local taxes, U.S. federal gift and estate tax laws or, except to the limited extent provided below, any non-U.S. tax consequences that may be relevant to investors in light of their particular circumstances.

Special rules different from those described below may apply to certain investors that are subject to special treatment under the Code, such as:

• insurance companies, banks and other financial institutions;

• tax-exempt organizations (including private foundations) and tax-qualified retirement plans;

• foreign governments and international organizations;

• broker-dealers and traders in securities;

• U.S. expatriates and certain former citizens or long-term residents of the United States;

• Non-U.S. Holders (as defined below) that own, or are deemed to own, more than 5% of our common stock (directly, indirectly or by attribution), including, for this purpose, our pre-funded warrants;

• persons required for U.S. federal income tax purposes to conform the timing of income accruals to their financial statements under Section 451(b) of the Code;

• “controlled foreign corporations,” “passive foreign investment companies” and corporations that accumulate earnings to avoid U.S. federal income tax;

• persons that hold our common stock or pre-funded warrants as part of a “straddle,” “hedge,” “conversion transaction,” “synthetic security” or integrated investment or other risk reduction strategy;

• U.S. Holders (as defined below) whose functional currency for U.S. tax purposes is not the U.S. dollar;

• persons who do not hold our common stock or pre-funded warrants as “capital assets” within the meaning of Section 1221 of the Code (generally, for investment purposes)

• regulated investment companies;

• pension plans;

• “qualified foreign pension funds” as defined in Section 897(l)(2) of the Code and entities all of the interests of which are held by qualified foreign pension funds;

• persons deemed to sell our common stock or pre-funded warrants under the constructive sale provisions of the Code; and

• persons who hold or receive our common stock or pre-funded warrants pursuant to the exercise of any employee stock option or otherwise as compensation.

Such investors are urged to consult their own tax advisors to determine the U.S. federal, state, local and other tax consequences that may be relevant to them.

In addition, this discussion does not address the tax treatment of partnerships or other pass-through entities or persons who hold our common stock or pre-funded warrants through partnerships or other entities which are pass-through entities for U.S. federal income tax purposes. If a partnership or other pass-through entity holds our common stock or pre-funded warrants, the tax treatment of a partner will generally depend upon the stratus of the partner and the activities of the partnership or other pass-through entity. A partner in a partnership or other

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pass-through entity that will hold our common stock or pre-funded warrants should consult his, her or its own tax advisor regarding the tax consequences of the ownership and disposition of our common stock or pre-funded warrants through a partnership or other pass-through entity, as applicable.

Furthermore, the discussion below is based upon the provisions of the Code, and Treasury regulations, rulings and judicial decisions thereunder as of the date hereof, and such authorities may be repealed, revoked or modified, possibly retroactively, and are subject to differing interpretations which could result in U.S. federal income tax consequences different from those discussed below. We have not requested a ruling from the Internal Revenue Service, or the IRS, with respect to the statements made and the conclusions reached in the following summary, and there can be no assurance that the IRS will agree with such statements and conclusions or will not take a contrary position regarding the tax consequences described herein, or that any such contrary position would not be sustained by a court.

For the purposes of this discussion, a “U.S. Holder” means a beneficial owner of our common stock or pre-funded warrants, other than a partnership or other pass-through entity, that is, for U.S. federal income tax purposes, (a) an individual who is a citizen or resident of the United States, (b) a corporation (or other entity taxable as a corporation for U.S. federal income tax purposes), created or organized in or under the laws of the United States, any state thereof or the District of Columbia, (c) an estate, the income of which is subject to U.S. federal income taxation regardless of its source, or (d) a trust if it (1) is subject to the primary supervision of a court within the United States and one or more ”United States persons” (within the meaning of Section 7701(a)(30) of the Code) have the authority to control all substantial decisions of the trust or (2) has a valid election in effect under applicable U.S. Treasury regulations to be treated as a U.S. person.

If you are an individual non-U.S. citizen, you may, in some cases, be deemed to be a resident alien (as opposed to a nonresident alien) by virtue of being present in the United States for at least 31 days in the calendar year and for an aggregate of at least 183 days during a three-year period ending in the current calendar year. Generally, for this purpose, all the days present in the current year, one-third of the days present in the immediately preceding year, and one-sixth of the days present in the second preceding year, are counted.

Resident aliens are generally subject to U.S. federal income tax as if they were U.S. citizens. Individuals who are uncertain of their status as resident or nonresident aliens for U.S. federal income tax purposes are urged to consult their own tax advisors regarding the U.S. federal income tax consequences of the ownership or disposition of our common stock or pre-funded warrants.

PERSONS CONSIDERING THE PURCHASE OF OUR COMMON STOCK OR PRE-FUNDED WARRANTS PURSUANT TO THIS OFFERING SHOULD CONSULT THEIR OWN TAX ADVISORS CONCERNING THE U.S. FEDERAL INCOME TAX CONSEQUENCES OF ACQUIRING, OWNING AND DISPOSING OF OUR COMMON STOCK AND PRE-FUNDED WARRANTS IN LIGHT OF THEIR PARTICULAR SITUATIONS AS WELL AS ANY CONSEQUENCES ARISING UNDER THE LAWS OF ANY OTHER TAXING JURISDICTION, INCLUDING ANY STATE, LOCAL OR NON-U.S. TAX CONSEQUENCES OR ANY U.S. FEDERAL NON-INCOME TAX CONSEQUENCES, AND THE POSSIBLE APPLICATION OF TAX TREATIES.

Characterization of the Pre-Funded Warrants for Tax Purposes

Although the characterization of the pre-funded warrants for U.S. federal income tax purposes is not entirely clear, because the exercise price of the pre-funded warrants is a nominal amount, we expect to treat the pre-funded warrants as our common stock for U.S. federal income tax purposes and a holder of pre-funded warrants should generally be taxed in the same manner as a holder of common stock as described below. Accordingly, for U.S. federal income tax purposes, no gain or loss should be recognized upon the exercise of a pre-funded warrant (other than with respect to cash paid in lieu of a fractional share), and upon exercise, the holding period of the share of common stock received should include the holding period of the pre-funded

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warrant. Similarly, the tax basis of a share of common stock received upon exercise of a pre-funded warrant should include the tax basis of the pre-funded warrant increased by the exercise price of $0.001 per share. The balance of this discussion generally assumes that the characterization described above is respected for U.S. federal income tax purposes, and the discussion below, to the extent it pertains to our common stock, is generally intended to also pertain to the pre-funded warrants.

Our position with respect to the characterization of pre-funded warrants is not binding on the IRS and the IRS may treat the pre-funded warrants as warrants to acquire our common stock and, if so, the amount and character of your gain with respect to an investment in our pre-funded warrants could change. You should consult your tax advisor regarding the characterization of pre-funded warrants for U.S. federal income tax purposes, and the consequences to you of an investment in the pre-funded warrants based on your own particular facts and circumstances.

Tax Consequences to U.S. Holders

Distributions on Common Stock and Pre-funded Warrants

As stated under “Dividend Policy,” we do not expect to make distributions on our common stock (or pre-funded warrants) in the foreseeable future. In the event that we do make distributions of cash or other property, distributions paid on common stock (or pre-funded warrants) will be treated as a dividend to the extent paid out of our current or accumulated earnings and profits (as determined under U.S. federal income tax principles). Dividends received by individuals may be eligible to be taxed at the lower applicable qualified dividends rate, provided certain holding period requirements are satisfied. Distributions in excess of our current and accumulated earnings and profits will be treated as a return of capital to the extent of a U.S. Holder’s tax basis in the common stock (or pre-funded warrant) and thereafter as capital gain from the sale or exchange of such common stock (or pre-funded warrant). The tax treatment of such gain is further described in “—Sale or Other Disposition of Common Stock or Pre-Funded Warrants” below. Dividends received by a corporation may be eligible for a dividends received deduction, subject to applicable limitations. Any such distributions will also be subject to the discussions below under the section titled “—Information Reporting and Backup Withholding.”

A U.S. Holder of a pre-funded warrant is expected to receive any distributions paid with respect to common stock prior to the exercise of the pre-funded warrant and, in such case, would be taxed in the same manner as a U.S. Holder of common stock that receives such a distribution. However, under certain circumstances, it is possible for cash to be held in abeyance for the U.S. Holder until a pre-funded warrant is exercised or the ownership limitations (described under “Description of Pre-Funded Warrants”) would not be exceeded, at which time such U.S. Holder shall be entitled to receive distributions. It is possible that such entitlement to distributions could cause the declaration of a distribution on our common stock to be currently taxable to U.S. Holders of pre-funded warrants, including under the principles governing Section 305 of the Code, even though the holders will not receive such distributions until a future date. Additionally, it is possible that other adjustments to the terms of the pre-funded warrant can be considered a constructive distribution under Section 305 of the Code. A holder of a pre-funded warrant should consult its tax advisor regarding the tax treatment of any distribution with respect to such pre-funded warrant that is held in abeyance in connection with any applicable limitation on the holder’s beneficial ownership of our common stock.

Sale or Other Disposition of Common Stock or Pre-Funded Warrants

For U.S. federal income tax purposes, gain or loss realized on the sale or other disposition of common stock or pre-funded warrants will be capital gain or loss, and will be long-term capital gain or loss if you have held the common stock or pre-funded warrants for more than one year. The amount of the gain or loss will equal the difference between your adjusted tax basis in the common stock or pre-funded warrants disposed of and the amount realized on the disposition. Long-term capital gains recognized by non-corporate U.S. Holders will be subject to reduced tax rates. The deductibility of capital losses is subject to limitations.

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Information Reporting and Backup Withholding

Information reporting requirements generally will apply to any distributions on our common stock and pre-funded warrants, constructive distributions on our pre-funded warrants, and gross proceeds on the sale or other disposition of our common stock and pre-funded warrants, unless the U.S. Holder is an exempt recipient (such as a corporation), regardless of whether any tax was actually withheld. Backup withholding (currently at a 24% rate) will apply to those payments if the U.S. Holder fails to provide its correct taxpayer identification number, or certification of exempt status, or if the U.S. Holder is notified by the IRS that it has failed to report in full payments of interest and dividend income. Any amounts withheld under the backup withholding rules will be allowed as a refund or a credit against a U.S. Holder’s U.S. federal income tax liability provided the required information is furnished timely to the IRS.

If backup withholding is applied to you, you should consult with your own tax advisor to determine whether you have overpaid your U.S. federal income tax, and whether you are able to obtain a tax refund or credit of the overpaid amount.

Tax Consequences to Non-U.S. Holders

For purposes of this discussion, a “Non-U.S. Holder” is a beneficial owner of our common stock or pre-funded warrants that, for U.S. federal income tax purposes is not a U.S. Holder or a partnership (including any entity or arrangement treated as a partnership). If you are not a Non-U.S. Holder, this section does not apply to you.

Distributions on Common Stock and Pre-funded Warrants

As stated under “Dividend Policy,” we do not expect to make any distributions on our common stock (or pre-funded warrants) in the foreseeable future. If we do make distributions on our common stock (or pre-funded warrants), however, such distributions made to a Non-U.S. Holder will constitute dividends for U.S. tax purposes to the extent paid out of our current or accumulated earnings and profits (as determined under U.S. federal income tax principles). Distributions in excess of our current and accumulated earnings and profits will constitute a return of capital that is applied against and reduces, but not below zero, a Non-U.S. Holder’s adjusted tax basis in our common stock (or pre-funded warrants). Any remaining excess will be treated as gain realized as described below under the section titled “—Sale or Other Disposition of Common Stock and Pre-Funded Warrants.”

Any distribution on our common stock (or pre-funded warrants) that is treated as a dividend paid to a Non-U.S. Holder that is not effectively connected with the holder’s conduct of a trade or business in the United States will generally be subject to withholding tax at a 30% rate or such lower rate as may be specified by an applicable income tax treaty between the United States and the Non-U.S. Holder’s country of residence. To obtain a reduced rate of withholding under a treaty, a Non-U.S. Holder generally will be required to provide the applicable withholding agent with a properly executed IRS Form W-8BEN, IRS Form W-8BEN-E or other appropriate form, certifying the Non-U.S. Holder’s entitlement to benefits under that treaty. Such form must be provided prior to the payment of dividends and must be updated periodically. If a Non-U.S. Holder holds stock through a financial institution or other agent acting on the holder’s behalf, the holder will be required to provide appropriate documentation to such agent. The holder’s agent may then be required to provide certification to the applicable withholding agent, either directly or through other intermediaries. If you are eligible for a reduced rate of U.S. withholding tax under an income tax treaty, you should consult with your own tax advisor to determine if you are able to obtain a refund or credit of any excess amounts withheld by timely filing an appropriate claim for a refund with the IRS.

We generally are not required to withhold tax on dividends paid (or constructive dividends deemed paid) to a Non-U.S. Holder that are effectively connected with the holder’s conduct of a trade or business within the

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United States (and, if required by an applicable income tax treaty, are attributable to a permanent establishment or fixed base that the holder maintains in the United States) if a properly executed IRS Form W-8ECI, stating that the dividends are so connected, is furnished to us (or, if shares of our common stock are held through a financial institution or other agent, to the applicable withholding agent). In general, such effectively connected dividends will be subject to U.S. federal income tax on a net income basis at the regular graduated rates applicable to U.S. persons, unless a specific treaty exemption applies. A corporate Non-U.S. Holder receiving effectively connected dividends may also be subject to an additional “branch profits tax,” which is imposed, under certain circumstances, at a rate of 30% (or such lower rate as may be specified by an applicable treaty) on the corporate Non-U.S. Holder’s effectively connected earnings and profits, subject to certain adjustments.

A Non-U.S. Holder of a pre-funded warrant is expected to receive any distributions paid with respect to common stock prior to the exercise of the pre-funded warrant and, in such case, would be taxed in the same manner as Non-U.S. Holder of common stock that receives such a distribution. However, under certain circumstances, it is possible for cash to be held in abeyance for a Non-U.S. Holder until a pre-funded warrant is exercised or the ownership limitations (described under “Description of Pre-Funded Warrants”) would not be exceeded, at which time the Non-U.S. Holder shall be entitled to receive distributions. It is possible that such entitlement to distributions could cause the declaration of a distribution on our common stock to be currently taxable to Non-U.S. Holders of pre-funded warrants, including under the principles governing Section 305 of the Code, even though such holders will not receive the distributions until a future date. Additionally, it is possible that other adjustments to the terms of the pre-funded warrant can be considered a constructive distribution under Section 305 of the Code. A holder of a pre-funded warrant should consult its tax advisor regarding the tax treatment of any distribution with respect to such pre-funded warrant that is held in abeyance in connection with any applicable limitation on the holder’s beneficial ownership of our common stock.

See also the section below titled “—Foreign Accounts” for additional withholding rules that may apply to dividends paid to certain foreign financial institutions or non-financial foreign entities.

Sale or Other Disposition of Common Stock and Pre-Funded Warrants

Subject to the discussion below under the sections titled “—Information Reporting and Backup Withholding” and “—Foreign Accounts,” a Non-U.S. Holder generally will not be subject to U.S. federal income or withholding tax with respect to gain realized on a sale or other disposition of our common stock or pre-funded warrants unless (a) the gain is effectively connected with a trade or business of the holder in the United States (and, if required by an applicable income tax treaty, is attributable to a permanent establishment that the holder maintains in the United States), (b) the Non-U.S. Holder is a nonresident alien individual and is present in the United States for a period or periods aggregating 183 or more days in the taxable year of the disposition and certain other conditions are met, or (c) we are or have been a “United States real property holding corporation” within the meaning of Code Section 897(c)(2) during the shorter of the 5-year period ending on the date of the disposition or the period that the Non-U.S. Holder held such class of stock, unless any class of our stock is regularly traded on an established securities market and the Non-U.S. Holder disposes of such class of stock and holds no more than 5% of such class of stock, directly or indirectly, actually or constructively.

If you are a Non-U.S. Holder described in (a) above, you will be required to pay tax on the net gain derived from the sale at the regular graduated U.S. federal income tax rates applicable to U.S. persons, unless a specific treaty exemption applies. Corporate Non-U.S. Holders described in (a) above may also be subject to the additional branch profits tax at a 30% rate or such lower rate as may be specified by an applicable income tax treaty. If you are an individual Non-U.S. Holder described in (b) above, you will be required to pay a flat 30% tax on the gain derived from the sale, which gain may be offset by certain U.S. source capital losses (even though you are not considered a resident of the United States), provided you have timely filed U.S. federal income tax returns with respect to such losses. With respect to (c) above, in general, we would be a U.S. real property holding corporation if interests in U.S. real estate comprised (by fair market value) at least half of our worldwide real property interests plus our other assets used or held for use in a trade or business. We believe that we are not,

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and do not anticipate becoming, a U.S. real property holding corporation. However, there can be no assurance that we will not become a U.S. real property holding corporation in the future. Our pre-funded warrants are expected to constitute a class of stock for purposes of the rules described above. However, we do not expect our pre-funded warrants to be regularly traded on an established securities market for purposes of such rule.

Information Reporting and Backup Withholding

Generally, we or certain financial middlemen must report information to the IRS with respect to any distributions we pay on our common stock or pre-funded warrants and any constructive distributions deemed paid on pre-funded warrants including the amount of any such distributions, the name and address of the recipient, and the amount, if any, of tax withheld. A similar report is sent to the holder to whom any such distributions are paid. Pursuant to tax treaties or certain other agreements, the IRS may make its reports available to tax authorities in the recipient’s country of residence.

Dividends paid by us (or our paying agents) to a Non-U.S. Holder may also be subject to U.S. backup withholding. U.S. backup withholding generally will not apply to a Non-U.S. Holder who provides a properly executed IRS Form W-8BEN or IRS Form W-8BEN-E, as applicable, or otherwise establishes an exemption, provided that the applicable withholding agent does not have actual knowledge or reason to know the holder is a U.S. person.

Under current U.S. federal income tax law, U.S. information reporting and backup withholding requirements generally will apply to the proceeds of a disposition of our common stock or pre-funded warrants effected by or through a U.S. office of any broker, U.S. or non-U.S., unless the Non-U.S. Holder provides a properly executed IRS Form W-8BEN or IRS Form W-8BEN-E, as applicable, or otherwise meets documentary evidence requirements for establishing non-U.S. person status or otherwise establishes an exemption. Generally, U.S. information reporting and backup withholding requirements will not apply to a payment of disposition proceeds to a Non-U.S. Holder where the transaction is effected outside the United States through a non-U.S. office of a non-U.S. broker. Information reporting and backup withholding requirements may, however, apply to a payment of disposition proceeds if the broker has actual knowledge, or reason to know, that the holder is, in fact, a U.S. person. For information reporting purposes, certain brokers with substantial U.S. ownership or operations will generally be treated in a manner similar to U.S. brokers.

Backup withholding is not an additional tax. If backup withholding is applied to you, you should consult with your own tax advisor to determine whether you have overpaid your U.S. federal income tax, and whether you are able to obtain a tax refund or credit of the overpaid amount.

Foreign Accounts

In addition to, and separately from the withholding rules described above, U.S. federal withholding taxes may apply under the Foreign Account Tax Compliance Act, or FATCA, on certain types of payments, including dividends (and deemed dividends) to non-U.S. financial institutions and certain other non-U.S. entities. Specifically, a 30% withholding tax may be imposed on dividends paid in respect of our common stock or pre-funded warrants, constructive distributions deemed paid with respect to pre-funded warrants and the gross proceeds of the disposition on our common stock or pre-funded warrants paid to a “foreign financial institution” or a “non-financial foreign entity” (each as defined in the Code), unless (1) the foreign financial institution agrees to undertake certain diligence and reporting obligations, (2) the non-financial foreign entity either certifies it does not have any “substantial United States owners” (as defined in the Code) or furnishes identifying information regarding each substantial United States owner, or (3) the foreign financial institution or non-financial foreign entity otherwise qualifies for an exemption from these rules. The 30% federal withholding tax described in this paragraph cannot be reduced under an income tax treaty with the United States. If the payee is a foreign financial institution and is subject to the diligence and reporting requirements in (1) above, it must enter into an agreement with the U.S. Department of the Treasury requiring, among other things, that it undertake to identify accounts held by certain “specified

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United States persons” or “United States-owned foreign entities” (each as defined in the Code), annually report certain information about such accounts, and withhold 30% on certain payments to non-compliant foreign financial institutions and certain other account holders. Foreign financial institutions located in jurisdictions that have an intergovernmental agreement with the United States governing FATCA may be subject to different rules.

The Treasury Secretary has issued proposed regulations providing that the withholding provisions under FATCA do not apply with respect to payment of gross proceeds from a sale or other disposition of our common stock or pre-funded warrants, which may be relied upon by taxpayers until final regulations are issued. Prospective investors should consult their tax advisors regarding the potential application of withholding under FATCA to their investment in our common stock or pre-funded warrants.

EACH PROSPECTIVE INVESTOR SHOULD CONSULT ITS OWN TAX ADVISOR REGARDING THE TAX CONSEQUENCES OF PURCHASING, HOLDING AND DISPOSING OF OUR COMMON STOCK AND PRE-FUNDED WARRANTS, INCLUDING THE CONSEQUENCES OF ANY PROPOSED CHANGE IN APPLICABLE LAW, AS WELL AS TAX CONSEQUENCES ARISING UNDER ANY STATE, LOCAL, NON-U.S. OR U.S. FEDERAL NON-INCOME TAX LAWS SUCH AS ESTATE AND GIFT TAX.

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DESCRIPTION OF PRE-FUNDED WARRANTS

The following is a brief summary of certain terms and conditions of the pre-funded warrants being offered by this prospectus supplement. The following description is subject in all respects to the provisions contained in the pre-funded warrants.

Form

The pre-funded warrants will be issued as individual warrant agreements to the investors. The form of pre-funded warrant will be filed as an exhibit to our Current Report on Form 8-K that we expect to file with the SEC in connection with this offering.

Term

The pre-funded warrants will not expire.

Exercisability

The pre-funded warrants are exercisable at any time between their original issuance and their expiration. The pre-funded warrants will be exercisable, at the option of each holder, in whole or in part by delivering to us a duly executed exercise notice solely by means of a cashless exercise, in which the holder would receive upon such exercise the net number of shares of our common stock determined according to the formula set forth in the pre-funded warrant. No fractional shares of common stock will be issued in connection with the exercise of a pre-funded warrant. In lieu of fractional shares, we will pay the holder an amount in cash equal to the fractional amount multiplied by the last trade price of our common stock on the exercise date.

Exercise limitations

Under the pre-funded warrants, we may not effect the exercise of any pre-funded warrant, and a holder will not be entitled to exercise any portion of any pre-funded warrant, (i) if immediately prior to exercise the holder (together with its affiliates) beneficially owns an aggregate number of shares of our common stock greater than 4.99% or 9.99%, as applicable, of the number of shares of our common stock outstanding immediately before giving effect to the exercise of any pre-funded warrant or (ii) to the extent that immediately following exercise, the holder (together with its affiliates) would beneficially own in excess of 4.99% or 9.99%, as applicable, of the number of shares of common stock outstanding immediately after giving effect to the issuance of such shares of common stock, and without taking account any other pre-funded warrants. However, any holder may increase or decrease such percentage to any other percentage not in excess of 19.99% upon at least 61 days’ prior notice from the holder to us.

Exercise price

The exercise price per whole share of our common stock purchasable upon the exercise of the pre-funded warrants is $0.001 per share of common stock. The exercise price of the pre-funded warrants and the number of shares of our common stock issuable upon exercise of the pre-funded warrants is subject to appropriate adjustment in the event of certain stock dividends and distributions, stock splits, stock combinations, reclassifications or similar events affecting our common stock. The exercise price will not be adjusted below the par value of our common stock.

Transferability

Subject to applicable laws, the pre-funded warrants may be offered for sale, sold, transferred or assigned without our consent. The pre-funded warrants will be held in definitive form by the purchasers. The ownership of the pre-funded warrants and any transfers of the pre-funded warrants will be registered in a warrant register maintained by us or our transfer agent.

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Exchange listing

We do not plan on applying to list the pre-funded warrants on the Nasdaq Global Select Market, any other national securities exchange or any other nationally recognized trading system.

Warrant agent

We will initially serve as the warrant agent under the pre-funded warrants.

Fundamental transactions

Upon the consummation of a fundamental transaction (as described in the pre-funded warrants, and generally including any reorganization, recapitalization or reclassification of our common stock, the sale, transfer or other disposition of all or substantially all of our assets, our consolidation or merger with or into another person in which we are not the surviving entity, the acquisition of more than 50% of our outstanding common stock, or any person or group becoming the beneficial owner of 50% of the voting power of our outstanding common stock), the holders of the pre-funded warrants will be entitled to receive, upon exercise of the pre-funded warrants, the same kind and amount of securities, cash or other property that such holders would have received had they exercised the pre-funded warrants immediately prior to such fundamental transaction, without regard to any limitations on exercise contained in the pre-funded warrants. Notwithstanding the foregoing, in the event of a fundamental transaction where the consideration consists solely of cash, solely of marketable securities or a combination of cash and marketable securities, then each pre-funded warrant shall automatically be deemed to be exercised in full in a cashless exercise effective immediately prior to and contingent upon the consummation of such fundamental transaction.

No rights as a stockholder

Except by virtue of such holder’s ownership of shares of our common stock, the holder of a pre-funded warrant does not have the rights or privileges of a holder of our common stock, including any voting rights, until such holder exercises the pre-funded warrant. Additionally, a holder is generally not entitled to receive distributions paid with respect to common stock prior to the exercise of the pre-funded warrant, and instead such distributions are expected to be held in abeyance for the holder until such pre-funded warrant is exercised or the ownership limitations would not be exceeded, at which time such holder shall be entitled to receive such distributions.

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UNDERWRITING

Leerink Partners LLC is acting as representative of each of the underwriters named below. Leerink Partners LLC and Cantor Fitzgerald & Co. are acting as joint bookrunning managers for this offering. Subject to the terms and conditions set forth in the underwriting agreement among us and the underwriters, we have agreed to sell to the underwriters, and each of the underwriters has agreed, severally and not jointly, to purchase from us, the number of shares of common stock and pre-funded warrants set forth opposite its name below.

Underwriter		Number of Shares				Number of Pre-Funded Warrants
Leerink Partners LLC			14,716,336				2,258,521
Cantor Fitzgerald & Co.			6,307,001				967,937
Total			21,023,337				3,226,458

Subject to the terms and conditions set forth in the underwriting agreement, the underwriters have agreed, severally and not jointly, to purchase all of the shares of common stock and pre-funded warrants sold under the underwriting agreement if any of the shares and pre-funded warrants are purchased. If an underwriter defaults, the underwriting agreement provides that the purchase commitments of the non-defaulting underwriters may be increased or the underwriting agreement may be terminated.

We have agreed to indemnify the underwriters against certain liabilities, including liabilities under the Securities Act, or to contribute to payments the underwriters may be required to make in respect of those liabilities.

The underwriters are offering the shares and pre-funded warrants, subject to prior sale, when, as and if issued to and accepted by them, subject to approval of legal matters by their counsel, including the validity of the shares and pre-funded warrants, and subject to other conditions contained in the underwriting agreement, such as the receipt by the underwriters of officers’ certificates and legal opinions. The underwriters reserve the right to withdraw, cancel or modify offers to the public and to reject orders in whole or in part.

Discounts and Commissions

The representative has advised us that the underwriters propose initially to offer the shares and pre-funded warrants to the public at the offering price set forth on the cover page of this prospectus supplement and to dealers at that price less a concession not in excess of $0.3118 per share and $0.3118 per pre-funded warrant. After the initial offering, the offering price, concession or any other term of this offering may be changed by the representative.

The following table shows the offering price, underwriting discounts and commissions and proceeds, before expenses, to us.

		Per Share				Per Pre-Funded Warrant				Total
Offering price		$	8.6600			$	8.6590			$	209,999,998
Underwriting discounts and commissions		$	0.5196			$	0.5196			$	12,600,193
Proceeds, before expenses, to us		$	8.1404			$	8.1394			$	197,399,805

We estimate expenses payable by us in connection with this offering, other than the underwriting discounts and commissions referred to above, will be approximately $373,000. We also have agreed to reimburse the underwriters for their FINRA counsel fee. In accordance with FINRA Rule 5110, this reimbursed fee is deemed underwriting compensation for this offering.

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No Sales of Similar Securities

We, our executive officers and directors and certain or our existing security holders have agreed not to sell or transfer any common stock or securities convertible into or exchangeable or exercisable for common stock, for 60 days after the date of this prospectus supplement without first obtaining the written consent of Leerink Partners LLC on behalf of the underwriters. Specifically, we and these other persons have agreed, with certain limited exceptions, not to directly or indirectly:

• offer, pledge, sell or contract to sell any common stock;

• sell any option or contract to purchase any common stock;

• purchase any option or contract to sell any common stock;

• grant any option, right or warrant for the sale of any common stock;

• otherwise dispose of or transfer any common stock;

• request or demand that we file a registration statement related to the common stock; or

• enter into any swap or other agreement or any transaction that transfers, in whole or in part, the economic consequence of ownership of any common stock, whether any such swap, agreement or transaction is to be settled by delivery of shares or other securities, in cash or otherwise.

The lock-up provisions apply to common stock and to securities convertible into or exchangeable or exercisable for common stock. They also apply to common stock owned now or acquired later by the person executing the lock-up agreement or for which the person executing the lock-up agreement later acquires the power of disposition.

Nasdaq Global Market Listing

Our common stock is listed on the Nasdaq Global Market under the symbol “TNGX.” We do not intend to list the pre-funded warrants on the Nasdaq Global Market or any other national securities exchange or nationally recognized trading system.

Price Stabilization, Short Positions and Penalty Bids

Until the distribution of the shares is completed, SEC rules may limit underwriters and selling group members from bidding for and purchasing our common stock. However, the representative may engage in transactions that stabilize the price of the common stock, such as bids or purchases to peg, fix or maintain that price.

In connection with this offering, the underwriters may purchase and sell our common stock in the open market. These transactions may include short sales, purchases on the open market to cover positions created by short sales and stabilizing transactions. Short sales involve the sale by the underwriters of a greater number of shares than they are required to purchase in this offering. Because we have not granted the underwriters an option to purchase additional shares, the underwriters must close out any short position by purchasing shares in the open market. Stabilizing transactions consist of various bids for or purchases of shares of common stock made by the underwriters in the open market prior to the closing of this offering.

The underwriters may also impose a penalty bid. This occurs when a particular underwriter repays to the underwriters a portion of the underwriting discount received by it because the representative has repurchased shares sold by or for the account of such underwriter in stabilizing or short covering transactions.

Similar to other purchase transactions, the underwriters’ purchases to cover the syndicate short sales may have the effect of raising or maintaining the market price of our common stock or preventing or retarding a

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decline in the market price of our common stock. As a result, the price of our common stock may be higher than the price that might otherwise exist in the open market. The underwriters may conduct these transactions on the Nasdaq Global Market, in the over-the-counter market or otherwise.

Neither we nor any of the underwriters make any representation or prediction as to the direction or magnitude of any effect that the transactions described above may have on the price of our common stock. In addition, neither we nor any of the underwriters make any representation that the representative will engage in these transactions or that these transactions, once commenced, will not be discontinued without notice.

Electronic Distribution

In connection with this offering, certain of the underwriters or securities dealers may distribute prospectuses by electronic means, such as e-mail.

Other Relationships

The underwriters and certain of their affiliates are full service financial institutions engaged in various activities, which may include securities trading, commercial and investment banking, financial advisory, investment management, investment research, principal investment, hedging, financing and brokerage activities. Some of the underwriters and certain of their affiliates may in the future engage in investment banking and other commercial dealings in the ordinary course of business with us and our affiliates, for which they may in the future receive customary fees, commissions and expenses.

In addition, in the ordinary course of their business activities, the underwriters and their affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers. Such investments and securities activities may involve securities and/or instruments of ours or our affiliates. The underwriters and their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

Selling Restrictions

Notice to Prospective Investors in the European Economic Area

In relation to each Member State of the European Economic Area (each, a “Relevant State”), no shares have been offered or will be offered pursuant to the offering to the public in that Relevant State prior to the publication of a prospectus in relation to the shares which has been approved by the competent authority in that Relevant State or, where appropriate, approved in another Relevant State and notified to the competent authority in that Relevant State, all in accordance with the Prospectus Regulation, except that shares may be offered to the public in that Relevant State at any time:

A. to any legal entity which is a qualified investor as defined under Article 2 of the Prospectus Regulation;

B. to fewer than 150 natural or legal persons (other than qualified investors as defined under Article 2 of the Prospectus Regulation), subject to obtaining the prior consent of the representative for any such offer; or

C. in any other circumstances falling within Article 1(4) of the Prospectus Regulation,

provided that no such offer of shares shall require us or the representative to publish a prospectus pursuant to Article 3 of the Prospectus Regulation or supplement a prospectus pursuant to Article 23 of the Prospectus Regulation.

For the purposes of this provision, the expression an “offer to the public” in relation to any shares in any Relevant State means the communication in any form and by any means of sufficient information on the terms of the offer and any shares to be offered so as to enable an investor to decide to purchase or subscribe for any shares, and the expression “Prospectus Regulation” means Regulation (EU) 2017/1129, as amended.

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Notice to Prospective Investors in the United Kingdom

No shares have been offered or will be offered pursuant to the offering to the public in the United Kingdom prior to the publication of a prospectus in relation to the Shares which has been approved by the Financial Conduct Authority, except that the shares may be offered to the public in the United Kingdom at any time:

A. to any legal entity which is a qualified investor as defined under Article 2 of the UK Prospectus Regulation;

B. to fewer than 150 natural or legal persons (other than qualified investors as defined under Article 2 of the UK Prospectus Regulation), subject to obtaining the prior consent of the representative for any such offer; or

C. in any other circumstances falling within Section 86 of the Financial Services and Markets Act 2000 (the “FMSA”),

provided that no such offer of the shares shall require us or any representative to publish a prospectus pursuant to Section 85 of the FSMA or supplement a prospectus pursuant to Article 23 of the UK Prospectus Regulation. For the purposes of this provision, the expression an “offer to the public” in relation to the shares in the United Kingdom means the communication in any form and by any means of sufficient information on the terms of the offer and any shares to be offered so as to enable an investor to decide to purchase or subscribe for any shares and the expression “UK Prospectus Regulation” means Regulation (EU) 2017/1129 as it forms part of domestic law by virtue of the European Union (Withdrawal) Act 2018.

Notice to Prospective Investors in Canada

The shares may be sold only to purchasers purchasing, or deemed to be purchasing, as principal that are accredited investors, as defined in National Instrument 45-106 Prospectus Exemptions or subsection 73.3(1) of the Securities Act (Ontario), and are permitted clients, as defined in National Instrument 31-103 Registration Requirements, Exemptions and Ongoing Registrant Obligations. Any resale of the shares must be made in accordance with an exemption from, or in a transaction not subject to, the prospectus requirements of applicable securities laws.

Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus supplement (including any amendment thereto) contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory for particulars of these rights or consult with a legal advisor.

Pursuant to section 3A.3 of National Instrument 33-105 Underwriting Conflicts (NI 33-105), the underwriters are not required to comply with the disclosure requirements of NI 33-105 regarding underwriter conflicts of interest in connection with this offering.

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LEGAL MATTERS

Certain legal matters in connection with this offering will be passed upon for us by Goodwin Procter LLP, Boston, Massachusetts. Certain legal matters in connection with this offering will be passed upon for the underwriter by Cooley LLP, Boston, Massachusetts.

EXPERTS

The financial statements and management’s assessment of the effectiveness of internal control over financial reporting (which is included in Management’s Report on Internal Control Over Financial Reporting) incorporated in this Prospectus by reference to the Annual Report on Form 10-K for the year ended December 31, 2024 have been so incorporated in reliance on the report (which contains an explanatory paragraph relating to the Company’s incurrence of significant operating losses and expectation to continue generating operating losses and negative cash flows from operations for the foreseeable future as described in Note 1 to the financial statements) of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at www.sec.gov.

Our website address is https://tangotx.com. The information on our website, however, is not, and should not be deemed to be, a part of this prospectus supplement or the accompanying prospectus.

This prospectus supplement and the accompanying prospectus is part of a registration statement on Form S-3 that we filed with the SEC and does not contain all of the information in the registration statement. The full registration statement may be obtained from the SEC or us, as provided above. Statements in this prospectus supplement and the accompanying prospectus about any documents filed as exhibits to the registration statement are summaries, and each statement is qualified in all respects by reference to the document to which it refers. You should refer to the actual documents for a more complete description of the relevant matters. You may inspect a copy of the registration statement through the SEC’s website, as provided above.

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INCORPORATION BY REFERENCE

The SEC allows us to incorporate by reference the information and reports we file with it, which means that we can disclose important information to you by referring you to these documents. The information incorporated by reference is an important part of this prospectus supplement, and information that we file later with the SEC will automatically update and supersede the information already incorporated by reference. We are incorporating by reference the documents listed below, which we have already filed with the SEC (SEC File No. 001-39385), and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, including all filings made after the date of this prospectus supplement, except as to any portion of any future report or document that is not deemed filed under such provisions until we sell all of the securities:

• Annual Report on Form 10-K for the year ended December 31, 2024, filed with the SEC on February 27, 2025;

• The information specifically incorporated by reference into our Annual Report on Form 10-K for the year ended December  31, 2024 from our definitive proxy statement on Schedule 14A (other than information furnished rather than filed), which was filed with the SEC on April 21, 2025;

• Quarterly Reports on Form 10-Q filed with the SEC for the quarters ended March 31, 2025 and June 30, 2025 filed with the SEC on May 12, 2025 and August 5, 2025, respectively;

• Current Reports on Form 8-K filed with the SEC on June 6, 2025 and August  25, 2025 and October 23, 2025, excluding information “furnished” pursuant to Items 7.01 or 9.01; and

• The description of our common stock contained in our Registration Statement on Form 8-A (File No. 001-39385) as filed with the SEC on September  2, 2020, including any amendments or reports filed for the purpose of updating this description, including Exhibit 4.2 to our Annual Report on Form 10-K for the year ended December 31, 2024, as filed with the SEC on February 27, 2025.

Upon request, we will provide, without charge, to each person, including any beneficial owner, to whom a copy of this prospectus supplement is delivered, a copy of the documents incorporated by reference into this prospectus supplement but not delivered with the prospectus supplement. You may request a copy of these filings, and any exhibits we have specifically incorporated by reference as an exhibit in this prospectus supplement, at no cost by writing or telephoning us at the following address: Tango Therapeutics, Inc., 201 Brookline Avenue, Suite 901, Boston, Massachusetts 02215, telephone: (857) 320-4900. You may also access these documents, free of charge on the SEC’s website at www.sec.gov or on our website at https://tangotx.com. Information contained on our website is not incorporated by reference into this prospectus supplement, and you should not consider any information on, or that can be accessed from, our website as part of this prospectus supplement or the accompanying prospectus.

Notwithstanding the foregoing, unless specifically stated to the contrary, information that we furnish (and that is not deemed “filed” with the SEC) under Items 2.02 and 7.01 of any Current Report on Form 8-K, including the related exhibits under Item 9.01, is not incorporated by reference into this prospectus supplement or the registration statement of which this prospectus supplement is a part.

This prospectus supplement and the accompanying prospectus are part of a registration statement we filed with the SEC. We have incorporated exhibits into the registration statement. You should read the exhibits carefully for provisions that may be important to you.

You should rely only on the information incorporated by reference or provided in this prospectus supplement and the accompanying prospectus. We have not authorized anyone to provide you with different information. We are not making an offer of these securities in any state where the offer is not permitted. You should not assume that the information in this prospectus supplement, the accompanying prospectus or in the documents incorporated by reference is accurate as of any date other than the date on the front of this prospectus supplement or those documents.

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Any statement contained in a document that is incorporated by reference will be modified or superseded for all purposes to the extent that a statement contained in this prospectus supplement or in any other document that is subsequently filed with the SEC and incorporated by reference into this prospectus supplement and the accompanying prospectus, modifies or is contrary to that previous statement. Any statement so modified or superseded will not be deemed a part of this prospectus supplement and the accompanying prospectus, except as so modified or superseded. Since information that we later file with the SEC will update and supersede previously incorporated information, you should look at all of the SEC filings that we incorporate by reference to determine if any of the statements in this prospectus supplement or in any documents previously incorporated by reference have been modified or superseded.

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PROSPECTUS

$400,000,000

Tango Therapeutics, Inc.

Common Stock

Preferred Stock

Debt Securities

Warrants

Units

We may offer and sell, from time to time issue, in one or more series or classes, up to $400,000,000 in aggregate principal amount of our common stock, preferred stock, debt securities, warrants and/or units, in any combination, together or separately, in one or more offerings in amounts, at prices and on the terms that we will determine at the time of the offering and which will be set forth in a prospectus supplement to this prospectus and any related free writing prospectus.

We may offer these securities separately or together in units. Each time we sell securities described herein, we will provide prospective investors with a supplement to this prospectus that will specify the terms of the securities being offered. See “Plan of Distribution” in this prospectus. We may sell these securities to or through underwriters or dealers and also to other purchasers or through agents. We will set forth the names of any underwriters or agents, and any fees, conversions, or discount arrangements, in the applicable prospectus supplement. We may not sell any securities under this prospectus without delivery of the applicable prospectus supplement. You should read this document and any prospectus supplement or amendment carefully before you invest in our securities.

Our common stock is listed on The Nasdaq Global Market under the symbol “TNGX.” On May 8, 2025, the closing price for our common stock, as reported on The Nasdaq Global Market, was $1.10 per share.

Investing in these securities involves certain risks. See “Risk Factors” on page 2 of this prospectus as well as those included in any accompanying prospectus supplement and in the documents incorporated by reference in this prospectus for a discussion of the factors you should carefully consider before deciding to purchase these securities.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is May 21, 2025.

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TABLE OF CONTENTS

ABOUT THIS PROSPECTUS			1
RISK FACTORS			2
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS			3
OUR COMPANY			5
USE OF PROCEEDS			6
SECURITIES THAT MAY BE OFFERED			7
DESCRIPTION OF CAPITAL STOCK			8
DESCRIPTION OF DEBT SECURITIES			11
DESCRIPTION OF WARRANTS			17
DESCRIPTION OF UNITS			18
PLAN OF DISTRIBUTION			21
LEGAL MATTERS			24
EXPERTS			24
WHERE YOU CAN FIND MORE INFORMATION			24
INCORPORATION BY REFERENCE			25

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we filed with the Securities and Exchange Commission, which we refer to as the “SEC,” utilizing a “shelf” registration process. Under this shelf registration process, we may from time to time sell any combination of the securities described in this prospectus in one or more offerings for an aggregate offering price of up to $400,000,000.

This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide one or more prospectus supplements that will contain specific information about the terms of the offering. The prospectus supplement may also add, update or change information contained in this prospectus. This prospectus, together with any accompanying prospectus supplement, contains important information you should know before investing in our securities, including important information about us and the securities being offered. You should read both this prospectus and the accompanying prospectus supplement together with the additional information described under the headings “Where You Can Find More Information” and “Incorporation by Reference” beginning on page 24 of this prospectus.

You should rely only on the information contained in or incorporated by reference in this prospectus, any accompanying prospectus supplement or in any related free writing prospectus filed by us with the SEC. We have not authorized anyone to provide you with different or additional information. If anyone provides you with different, additional or inconsistent information, you should not rely on it. We do not take responsibility for, and can provide no assurance as to the reliability of, any information that others may give you. This prospectus and the accompanying prospectus supplement do not constitute an offer to sell or the solicitation of an offer to buy any securities other than the securities described in the accompanying prospectus supplement or an offer to sell or the solicitation of an offer to buy such securities in any circumstances in which such offer or solicitation is unlawful. You should assume that the information appearing in this prospectus, any prospectus supplement, the documents incorporated by reference and any related free writing prospectus is accurate only as of their respective dates, regardless of the time of delivery of this prospectus, any applicable prospectus supplement or any sale of securities. Our business, financial condition, results of operations and prospects may have changed materially since those dates. This prospectus, any applicable prospectus supplement and the information incorporated herein or therein by reference contains market data, industry statistics and other data that have been obtained or compiled from information made available by independent third parties. We have not independently verified the accuracy and completeness of such data.

THIS PROSPECTUS MAY NOT BE USED TO OFFER AND SELL SECURITIES UNLESS IT IS ACCOMPANIED BY AN ADDITIONAL PROSPECTUS OR A PROSPECTUS SUPPLEMENT.

As used in this prospectus, unless the context otherwise requires, references to “Tango,” “company,” “we,” “us” and “our” refer to Tango Therapeutics, Inc. and, where appropriate, our subsidiaries.

We were formerly known as BCTG Acquisition Corp. (“BCTG”) and were incorporated in Delaware in May 2020 as a special purpose acquisition company, formed for the purpose of effecting a merger, capital stock exchange, asset acquisition, stock purchase, reorganization or other similar business. On August 10, 2021, we consummated the merger pursuant to the Agreement and Plan of Merger, dated as of April 13, 2021, by and among BCTG, BCTG Merger Sub Inc. and Tango Therapeutics Sub, Inc. Upon the consummation of the merger, we changed our name to “Tango Therapeutics, Inc.” We own various U.S. federal trademark applications and unregistered trademarks, including our company name. All other trademarks or trade names referred to in this prospectus are the property of their respective owners. Solely for convenience, the trademarks and trade names in this prospectus are referred to without the symbols ^® and ^™, but such references should not be construed as any indicator that their respective owners will not assert, to the fullest extent under applicable law, their rights thereto.

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RISK FACTORS

Investing in our securities involves a high degree of risk. You should carefully consider the risks set forth in our filings with the SEC that are incorporated by reference herein and any prospectus supplement, as well as other information we include or incorporate by reference into this prospectus and any applicable prospectus supplement, before making an investment decision. Our business, financial condition or results of operations could be materially adversely affected by the materialization of any of these risks. The trading price of our securities could decline due to the materialization of any of these risks, and you may lose all or part of your investment. This prospectus and the documents incorporated herein by reference also contain forward-looking statements that involve risks and uncertainties. Actual results could differ materially from those anticipated in these forward-looking statements as a result of certain factors, including the risks described in the documents incorporated herein by reference, including our most recent Annual Report on Form 10-K, our Quarterly Reports on Form 10-Q and our Current Reports on Form 8-K and the other documents we file with the SEC that are deemed incorporated by reference into this prospectus.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus, including the documents that we incorporate by reference, includes forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). Forward-looking statements relate to, among others, our plans, objectives and expectations for our business, operations and financial performance and condition, and can be identified by terminology such as “may,” “will,” “could,” “should,” “expect,” “intend,” “plan,” “anticipate,” “believe,” “estimate,” “predict,” “potential,” “project,” “seek,” “endeavor,” “target,” “continue” and similar expressions that do not relate solely to historical matters. Forward-looking statements are based on management’s belief and assumptions and on information currently available to management. Although we believe that the expectations reflected in forward-looking statements are reasonable, such statements involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by forward-looking statements.

Forward-looking statements include, but are not limited to, statements about:

∎ the initiation, timing, progress, results, and cost of our research and development programs and our current and future preclinical studies and clinical trials and combination clinical trials, including statements regarding the timing of IND filings and acceptance, active enrollment and dosing in clinical trials (including combination clinical trials), future plans for dose expansions and dose escalations, and initiation and completion of studies or clinical trials (including combination trials), plans for filing a registrational trial and initiating a combination clinical trial in TNG462, and related preparatory work for each, plans for the TNG456 clinical trial, and the period during which the results of the clinical trials (including initial and final trial results) will become available (such as the clinical data update from the ongoing TNG462 clinical trial and the data from the ongoing TNG260 clinical trial, both expected in the second half of 2025);

∎ our ability to discover and develop product candidates efficiently (including the advancement of development candidates on the timelines identified and the ability to identify and contract with clinical trial sites and investigators to use our product candidates in trials);

∎ our ability and potential (or those of third parties) to manufacture our drug product, drug substance and product candidates successfully for preclinical use, for clinical trials and on a larger scale for commercial use, if approved;

∎ the ability and willingness of our third-party strategic collaborators to license and to continue research and development activities relating to our development candidates and product candidates;

∎ our ability to obtain funding for our operations necessary to complete further research, development and commercialization of our product candidates (and that existing cash, cash equivalents and marketable securities will enable us to fund our operating expenses and capital expenditure requirements into the first quarter of 2027);

∎ our ability to obtain and, if approved, maintain regulatory approval of our product candidates (as well as approval or clearance of screening tests and companion diagnostic tests for our product candidates) and the potential paths to approval for TNG462 in MTAP-deleted pancreatic and lung cancer;

∎ our ability to commercialize our products, if approved;

∎ the pricing and reimbursement of our product candidates, if approved;

∎ the implementation of our business model, and strategic plans for our business and product candidates;

∎ the scope of protection we are able to establish and maintain for intellectual property rights covering our product candidates and our ability to enforce our intellectual property rights;

∎ estimates of our future expenses, capital requirements, and our need for additional financing;

∎ the potential benefits of strategic collaboration agreements, our ability to enter into strategic collaborations or arrangements, and our ability to attract collaborators with development, regulatory and commercialization expertise;

∎ future agreements with third parties in connection with the commercialization of product candidates (if approved) and any other approved products;

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∎ the size and growth potential of the markets for our product candidates, and our ability to serve those markets;

∎ our financial performance, including the expectation that we will continue to incur operating losses and negative cash flow;

∎ the rate and degree of market acceptance of our product candidates, if approved;

∎ regulatory developments in the United States and foreign countries, including product approval requirements and pricing regulations by U.S. regulatory authorities (such as the Centers for Medicare & Medicaid Services) and foreign regulatory authorities;

∎ our ability to contract with third-party suppliers and manufacturers and their ability to perform adequately;

∎ our ability (or the ability of third parties with whom we contract) to produce our products or product candidates with advantages in turnaround times or manufacturing cost;

∎ our ability to deliver the deep, sustained target inhibition necessary to optimize tumor response and clinical benefit as a result of the unique ability of synthetic lethal targeting to spare normal cells, as well as the success of competing therapies that are or may become available;

∎ our ability to attract and retain key scientific or management personnel;

∎ the impact of laws and regulations;

∎ developments relating to our competitors and industry;

∎ the impact of trade restrictions (such as sanctions or tariffs); regulatory requirements, legal actions, or enforcement; inflation rates; and inadequate funding for government agencies on our business, financial condition, and results of operations;

∎ the effect of public health crises on our business operations, including but not limited to our preclinical studies and clinical trials and any future studies or trials;

∎ the expected benefits of the use of our drugs in patients as single agents and/or in combination, including our beliefs that: TNG462 has the potential to be a best-in-class molecule; and preclinical studies demonstrate TNG456 brain exposure has the potential to be sufficient for meaningful efficacy in GBM; and

∎ other risks and uncertainties, including those under the caption “Risk Factors.”

The forward-looking statements in this prospectus represent our views as of the date of this prospectus. We anticipate that subsequent events and developments will cause our views to change. However, while we may elect to update these forward-looking statements at some point in the future, we have no current intention of doing so except to the extent required by applicable law. You should therefore not rely on these forward-looking statements as representing our views as of any date subsequent to the date of this prospectus.

We may from time-to-time provide estimates, projections and other information concerning our industry, our business and the markets for our programs, product candidates and collaborations. Information that is based on estimates, forecasts, projections, market research or similar methodologies is inherently subject to uncertainties and actual events or circumstances may differ materially from events and circumstances that are assumed in this information. Unless otherwise expressly stated, we obtained this industry, business, market, and other data from our own internal estimates and research as well as from reports, research surveys, studies, and similar data prepared by market research firms and other third parties, industry, medical and general publications, government data and similar sources. While we are not aware of any misstatements regarding any third-party information presented in this prospectus, their estimates, in particular, as they relate to projections, involve numerous assumptions, are subject to risks and uncertainties and are subject to change based on various factors. You should read this prospectus, any applicable prospectus supplement and any related free writing prospectus and the documents that we reference therein and have filed with the SEC as exhibits thereto completely and with the understanding that our actual future results may be materially different from any future results expressed or implied by these forward-looking statements. These estimates involve numerous assumptions, are subject to risks and uncertainties and are subject to change based on various factors, including those discussed under “Item 1A: Risk Factors” and elsewhere in our most recent Annual Report on Form 10-K, our subsequent Quarterly Reports on Form 10-Q and our Current Reports on Form 8-K, and the section of any accompanying prospectus supplement entitled “Risk Factors.”

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OUR COMPANY

Overview

Tango Therapeutics was founded with a clear mission: to discover the next wave of targeted therapies in oncology by addressing the specific genetic alterations that drive cancer. We develop new drugs directed at tumor suppressor gene loss in defined patient populations with high unmet medical need. Tumor suppressor gene loss remains a largely unaddressed target space specifically because these genetic events cannot be directly targeted. Our novel small molecules are designed to be selectively active in cancer cells with specific genetic alterations, killing those cancer cells while sparing normal cells. We also are extending this target space beyond the classic, cell-autonomous effects of tumor suppressor gene loss to include the discovery of novel targets that reverse tumor suppressor gene mediated immune evasion which prevents the immune system from recognizing and killing cancer cells. We believe our approach will provide the ability to deliver deep, durable target inhibition with favorable tolerability and safety profiles, thus potentially maximizing clinical benefit.

We are currently developing two MTA-cooperative PRMT5 inhibitors: TNG462 for non-CNS cancers, including pancreatic and lung cancer, and TNG456, our next-generation, brain-penetrant PRMT5 inhibitor, for CNS cancers, including GBM.

TNG260 is a first-in-class CoREST inhibitor, which in preclinical studies reversed the immune evasion effect of STK11 loss-of-function mutations. TNG260 has a favorable safety, tolerability and pharmacokinetic profile in dose escalation and clinical proof-of-mechanism has now been established based on pharmacodynamic data from on-treatment patient biopsies.

TNG961 is a development candidate targeting HBS1L in FOCAD-deleted solid tumors. FOCAD deletion occurs in 20-40% of all MTAP-deleted cancers. FOCAD deletion is common in NSCLC, occurring in ~7% of these patients. 20-40% of cancers with MTAP deletion have a coincident FOCAD deletion on chromosome 9, and cancers with FOCAD deletion are dependent on HBS1L for mRNA processing, thus protein synthesis. By degrading HBS1L and disrupting the HBS1L/PELO complex, TNG961 causes tumor regression in FOCAD-deleted preclinical models of multiple histologies.

Corporate History and Information

Tango Therapeutics, Inc. was incorporated in Delaware on May 21, 2020 under the name BCTG Acquisition Corp. On April 13, 2021, BCTG Acquisition Corp., BCTG Merger Sub Inc. and Tango Therapeutics, Inc. (now known as Tango Therapeutics Sub, Inc.) signed a definitive merger agreement (the “Merger Agreement”). Tango Therapeutics, Inc., prior to August 10, 2021, is referred to herein as Old Tango. Pursuant to the Merger Agreement, the business combination (“Business Combination”) was approved on August 9, 2021 by shareholders of BCTG Acquisition Corp. (“BCTG”), resulting in BCTG acquiring 100% of Old Tango’s issued and outstanding equity securities on August 10, 2021. As a result of the Business Combination, Tango Therapeutics, Inc. was renamed Tango Therapeutics Sub, Inc. (and is sometimes referred to as Old Tango) and BCTG was renamed “Tango Therapeutics, Inc.”

Our principal corporate office is located at 201 Brookline Avenue, Suite 901, Boston, MA 02215, and our telephone number is 857-320-4900. Our website address is https://tangotx.com. We do not incorporate the information on or accessible through our website into this prospectus, and you should not consider any information on, or that can be accessed through, our website as part of this prospectus.

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USE OF PROCEEDS

We currently intend to use the net proceeds from the sale of any security under this prospectus primarily for general corporate purposes, including funding working capital, operating expenses and to fund the research and development of our product candidates, including manufacturing and clinical trial expenses. We may also use the proceeds to make acquisitions or investments in businesses, products or technologies that are complementary to our own, although we have no current plans, commitments or agreements with respect to any acquisitions as of the date of this prospectus. Pending these uses, we may invest the net proceeds from this offering in short-term U.S. Treasury securities or other securities in accordance with our investment policy, or may hold such proceeds as cash, until they are used for their stated purpose. We have not determined the amount of net proceeds to be used specifically for such purposes. As a result, management will retain broad discretion over the allocation of net proceeds.

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SECURITIES THAT MAY BE OFFERED

This prospectus contains summary descriptions of the securities we may offer from time to time. These summary descriptions are not meant to be complete descriptions of each security. The particular terms of any security will be described in the applicable prospectus supplement. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities described herein, we will provide prospective investors with a supplement to this prospectus that will contain specific information about the terms of that offering, including the specific amounts, prices and terms of the securities offered. We may sell the securities to or through underwriters, dealers or agents, directly to purchasers or through a combination of any of these methods of sale or as otherwise set forth below under “Plan of Distribution.” We, as well as any agents acting on our behalf, reserve the sole right to accept and to reject in whole or in part any proposed purchase of securities. Any prospectus supplement will set forth the names of any underwriters, dealers, agents or other entities involved in the sale of securities described in that prospectus supplement and any applicable fee, commission or discount arrangements with them.

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DESCRIPTION OF CAPITAL STOCK

The following description of our capital stock is intended as a summary only and therefore is not a complete description of our capital stock. This description is based upon, and is qualified by reference to, our certificate of incorporation, our bylaws, and applicable provisions of Delaware corporate law. You should read our certificate of incorporation and our bylaws, in each case, as amended and supplemented, which are filed as exhibits to the registration statement of which this prospectus forms a part, for the provisions that are important to you.

Authorized and Outstanding Stock

Our certificate of incorporation authorizes the issuance of 210,000,000 shares, consisting of 200,000,000 shares of common stock, $0.001 par value per share, and 10,000,000 shares of preferred stock, $0.001 par value, all of which shares of preferred stock are undesignated.

Common Stock

Our certificate of incorporation provides the following with respect to the rights, powers, preferences and privileges of the common stock.

Voting Power. Except as otherwise required by law or as otherwise provided in any certificate of designation for any series of preferred stock, the holders of common stock possess all voting power for the election of Tango’s directors and all other matters requiring stockholder action. Holders of common stock are entitled to one vote per share on matters to be voted on by stockholders.

Dividends. Holders of common stock will be entitled to receive such dividends, if any, as may be declared from time to time by our board of directors in its discretion out of funds legally available therefor. In no event will any stock dividends or stock splits or combinations of stock be declared or made on common stock unless the shares of common stock at the time outstanding are treated equally and identically.

Liquidation, Dissolution and Winding Up. In the event of Tango’s voluntary or involuntary liquidation, dissolution, distribution of assets or winding-up, the holders of the common stock will be entitled to receive an equal amount per share of all of Tango’s assets of whatever kind available for distribution to stockholders, after the rights of the holders of the preferred stock have been satisfied.

Preemptive or Other Rights. Our common stock has no preemptive rights, conversion rights or other subscription rights or redemption or sinking fund provisions.

Listing of Securities

Our common stock is listed on the Nasdaq Global Market under the symbol “TNGX”.

Transfer Agent

The transfer agent for our common stock is Computershare Trust Company, N.A.

Preferred stock

Our board of directors will have the authority, without further action by our stockholders, to issue up to 10,000,000 shares of preferred stock in one or more series and to fix the rights, preferences, privileges and restrictions thereof. These rights, preferences and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences, sinking fund terms and the number of shares constituting, or the designation of, such series, any or all of which may be greater than the rights of common stock. The issuance of our preferred stock could adversely affect the voting power of holders of common stock and the likelihood that such holders will receive dividend payments and payments upon our liquidation. In addition, the issuance of preferred stock could have the effect of delaying, deferring or preventing a change in control of our company or other corporate action. No shares of convertible preferred stock are outstanding, and we have no present plan to issue any shares of convertible preferred stock.

Registration Rights

Certain of our stockholders (“Holders”) hold registration rights pursuant to an amended and restated registration and stockholder rights agreement (the “Amended and Restated Registration and Stockholder Rights Agreement”).

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Stockholders holding a majority-in-interest of such registrable securities are entitled to make a written demand for registration under the Securities Act of 1933, as amended (the “Securities Act”), of all or part of their registrable securities.

In particular, the Amended and Restated Registration and Stockholder Rights Agreement provides for the following registration rights:

∎ Shelf registration/demand registration rights. At any time and from time to time when an effective shelf registration statement is on file with the SEC, a Holder may request to sell all or any portion of such Holder’s registrable securities by means of an underwritten takedown off of the shelf registration statement, except that we are only obligated to effect such underwritten shelf takedown if such offering will include registrable securities proposed to be sold by the requesting Holder, either individually or together with other requesting Holders, with a total offering price reasonably expected to exceed, in the aggregate, $20.0 million. Additionally, we are not required to effect more than one underwritten shelf takedown in any six-month period.

∎ Piggyback registration rights. Subject to exceptions for certain offerings and registration statements, if at any time, we propose to file a registration statement under the Securities Act, in connection with an offering of our equity securities or securities or other obligations exercisable or exchangeable for, or convertible into, our equity securities, either for our own account or for the account of other stockholders, the Holders are entitled to include their registrable securities in such registration statement.

∎ Indemnification. The Amended and Restated Registration and Stockholder Rights Agreement contains customary cross-indemnification provisions, under which we are obligated to indemnify Holders of registrable securities in the event of material misstatements or omissions in the registration statement attributable to us, and Holders of registrable securities are obligated to indemnify us for material misstatements or omissions attributable to them.

Expiration of Registration Rights

The registration rights granted under the Amended and Restated Registration and Stockholder Rights Agreement will terminate on the earlier of (i) the 10th anniversary of the date of the agreement and (ii) with respect to any Holder, on the date that such Holder no longer holds any Registrable Securities.

Anti-Takeover Effects of our Certificate of Incorporation and Bylaws and Delaware Law

Certificate of Incorporation and Bylaws

Our certificate of incorporation and bylaws include a number of provisions that may have the effect of delaying, deferring or preventing another party from acquiring control of us and encouraging persons considering unsolicited tender offers or other unilateral takeover proposals to negotiate with our board of directors rather than pursue non-negotiated takeover attempts. These provisions include the items described below:

∎ permit our board of directors to issue up to 10,000,000 shares of preferred stock, with any rights, preferences and privileges as they may designate, including the right to approve an acquisition or other change of control;

∎ provide that the authorized number of directors may be changed only by resolution of our board of directors;

∎ provide that, subject to the rights of any series of preferred stock to elect directors, directors may be removed only with cause by the holders of at least two thirds (2/3) of all of our then-outstanding shares of the capital stock entitled to vote at an election of directors;

∎ provide that, subject to the rights of any series of preferred stock to fill director vacancies, all director vacancies, including newly created directorships, may, except as otherwise required by law, be filled by the affirmative vote of a majority of directors then in office, even if less than a quorum;

∎ provide that stockholders seeking to present proposals before a meeting of stockholders or to nominate candidates for election as directors at a meeting of stockholders must provide advance notice in writing, and also specify requirements as to the form and content of a stockholder’s notice;

∎ provide that special meetings of our stockholders may be called by our board of directors pursuant to a resolution adopted by a majority of the total number of directors then in office;

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∎ provide that our board of directors will be divided into three classes of directors, with the directors serving three-year terms, therefore making it more difficult for stockholders to change the composition of our board of directors;

∎ provide that any amendment of our certificate of incorporation must first be approved by a majority of our board of directors, and if required by law or our certificate of incorporation, must thereafter be approved by a majority of the outstanding shares entitled to vote on the amendment and a majority of the outstanding shares of each class entitled to vote thereon as a class, except that the amendment of the provisions relating to stockholder action, board composition, limitation of liability and certificate of incorporation must be approved by not less than two-thirds of the outstanding shares entitled to vote on the amendment, and not less than two-thirds of the outstanding shares of each class entitled to vote thereon as a class;

∎ our Bylaws may be amended by the affirmative vote of a majority of the directors then in office, subject to any limitations set forth by law or in the bylaws; and may also be amended by the affirmative vote of 75% of the outstanding shares entitled to vote on the amendment; provided, however, if our board of directors recommends such amendment to be voted on at a meeting of the stockholders, such amendment only requires the affirmative vote of the majority of the outstanding shares entitled to vote on such amendment and

∎ not provide for cumulative voting rights, therefore allowing the holders of a majority of the shares of common stock entitled to vote in any election of directors to elect all of the directors standing for election, if they should so choose.

Delaware Anti-Takeover Law

Tango has opted out of Section 203 of the Delaware General Corporation Law (the “DGCL”). Section 203 of the DGCL prohibits a Delaware corporation from engaging in a “business combination” with an “interested stockholder” (i.e. a stockholder owning 15% or more of company’s voting stock) for three years following the time that the “interested stockholder” becomes such, subject to certain exceptions.

Exclusive Jurisdiction of Certain Actions

Our bylaws require, to the fullest extent permitted by law, unless we consent in writing to the selection of an alternative forum, that derivative actions brought in the name of Tango, actions against any current or former directors, officers and employees for breach of fiduciary duty, actions asserting a claim arising pursuant to any provision of the DGCL or our certificate of incorporation or our bylaws, actions to interpret, apply, enforce or determine the validity of our certificate of incorporation or our bylaws and actions asserting a claim governed by the internal affairs doctrine may be brought only in the Court of Chancery in the State of Delaware (the “Delaware Forum Provision”). The Delaware Forum Provision will not apply to any causes of action arising under the Securities Act and the Securities Exchange Act of 1934. Our bylaws further provide that unless we consent in writing to the selection of an alternative forum, the federal district courts of the United States shall be the sole and exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act. We refer to such provision as the Federal Forum Provision. Our bylaws provide that any person or entity purchasing or otherwise acquiring any interest in shares of our capital stock is deemed to have notice of and consented to the Delaware Forum Provision and the Federal Forum Provision; provided, however, that stockholders cannot and will not be deemed to have waived our compliance with the U.S. federal securities laws and the rules and regulations thereunder.

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DESCRIPTION OF DEBT SECURITIES

We may issue debt securities from time to time, in one or more series, as either senior or subordinated debt or as senior or subordinated convertible debt. While the terms we have summarized below will apply generally to any debt securities that we may offer under this prospectus, we will describe the particular terms of any debt securities that we may offer in more detail in the applicable prospectus supplement. The terms of any debt securities offered under a prospectus supplement may differ from the terms described below. Unless the context requires otherwise, whenever we refer to the indenture, we also are referring to any supplemental indentures that specify the terms of a particular series of debt securities.

We will issue the debt securities under the indenture that we will enter into with the trustee named in the indenture. The indenture will be qualified under the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”). We have filed the form of indenture as an exhibit to the registration statement of which this prospectus is a part, and supplemental indentures and forms of debt securities containing the terms of the debt securities being offered will be filed as exhibits to the registration statement of which this prospectus is a part, or will be incorporated by reference from, reports that we file with the SEC.

The following summary of material provisions of the debt securities and the indenture is subject to, and qualified in its entirety by reference to, all of the provisions of the indenture applicable to a particular series of debt securities. We urge you to read the applicable prospectus supplements and any related free writing prospectuses related to the debt securities that we may offer under this prospectus, as well as the complete indenture that contains the terms of the debt securities.

General

The indenture does not limit the amount of debt securities that we may issue. It provides that we may issue debt securities up to the principal amount that we may authorize and may be in any currency or currency unit that we may designate. Except for the limitations on consolidation, merger and sale of all or substantially all of our assets contained in the indenture, the terms of the indenture do not contain any covenants or other provisions designed to give holders of any debt securities protection against changes in our operations, financial condition or transactions involving us.

We may issue the debt securities issued under the indenture as “discount securities,” which means they may be sold at a discount below their stated principal amount. These debt securities, as well as other debt securities that are not issued at a discount, may be issued with “original issue discount” (“OID”) for U.S. federal income tax purposes because of interest payment and other characteristics or terms of the debt securities. Material U.S. federal income tax considerations applicable to debt securities issued with OID will be described in more detail in any applicable prospectus supplement.

We will describe in the applicable prospectus supplement the terms of the series of debt securities being offered, including:

∎ the title of the series of debt securities;

∎ any limit upon the aggregate principal amount that may be issued;

∎ the maturity date or dates;

∎ the form of the debt securities of the series;

∎ the applicability of any guarantees;

∎ whether or not the debt securities will be secured or unsecured, and the terms of any secured debt;

∎ whether the debt securities rank as senior debt, senior subordinated debt, subordinated debt or any combination thereof, and the terms of any subordination;

∎ if the price (expressed as a percentage of the aggregate principal amount thereof) at which such debt securities will be issued is a price other than the principal amount thereof, the portion of the principal amount thereof payable upon declaration of acceleration of the maturity thereof, or if applicable, the portion of the principal amount of such debt securities that is convertible into another security or the method by which any such portion shall be determined;

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∎ the interest rate or rates, which may be fixed or variable, or the method for determining the rate and the date interest will begin to accrue, the dates interest will be payable and the regular record dates for interest payment dates or the method for determining such dates;

∎ our right, if any, to defer payment of interest and the maximum length of any such deferral period;

∎ if applicable, the date or dates after which, or the period or periods during which, and the price or prices at which, we may, at our option, redeem the series of debt securities pursuant to any optional or provisional redemption provisions and the terms of those redemption provisions;

∎ the date or dates, if any, on which, and the price or prices at which we are obligated, pursuant to any mandatory sinking fund or analogous fund provisions or otherwise, to redeem, or at the holder’s option to purchase, the series of debt securities and the currency or currency unit in which the debt securities are payable;

∎ the denominations in which we will issue the series of debt securities, if other than denominations of $1,000 and any integral multiple thereof;

∎ any and all terms, if applicable, relating to any auction or remarketing of the debt securities of that series and any security for our obligations with respect to such debt securities and any other terms which may be advisable in connection with the marketing of debt securities of that series;

∎ whether the debt securities of the series shall be issued in whole or in part in the form of a global security or securities; the terms and conditions, if any, upon which such global security or securities may be exchanged in whole or in part for other individual securities; and the depositary for such global security or securities;

∎ if applicable, the provisions relating to conversion or exchange of any debt securities of the series and the terms and conditions upon which such debt securities will be so convertible or exchangeable, including the conversion or exchange price, as applicable, or how it will be calculated and may be adjusted, any mandatory or optional (at our option or the holders’ option) conversion or exchange features, the applicable conversion or exchange period and the manner of settlement for any conversion or exchange;

∎ if other than the full principal amount thereof, the portion of the principal amount of debt securities of the series which shall be payable upon declaration of acceleration of the maturity thereof;

∎ additions to or changes in the covenants applicable to the particular debt securities being issued, including, among others, the consolidation, merger or sale covenant;

∎ additions to or changes in the events of default with respect to the securities and any change in the right of the trustee or the holders to declare the principal, premium, if any, and interest, if any, with respect to such securities to be due and payable;

∎ additions to or changes in or deletions of the provisions relating to covenant defeasance and legal defeasance;

∎ additions to or changes in the provisions relating to satisfaction and discharge of the indenture;

∎ additions to or changes in the provisions relating to the modification of the indenture both with and without the consent of holders of debt securities issued under the indenture;

∎ the currency of payment of debt securities if other than U.S. dollars and the manner of determining the equivalent amount in U.S. dollars;

∎ whether interest will be payable in cash or additional debt securities at our or the holders’ option and the terms and conditions upon which the election may be made;

∎ the terms and conditions, if any, upon which we will pay amounts in addition to the stated interest, premium, if any and principal amounts of the debt securities of the series to any holder that is not a “United States person” for federal tax purposes;

∎ any restrictions on transfer, sale or assignment of the debt securities of the series; and

∎ any other specific terms, preferences, rights or limitations of, or restrictions on, the debt securities, any other additions or changes in the provisions of the indenture, and any terms that may be required by us or advisable under applicable laws or regulations.

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Conversion or Exchange Rights

We will set forth in the applicable prospectus supplement the terms on which a series of debt securities may be convertible into or exchangeable for our common stock or our other securities. We will include provisions as to settlement upon conversion or exchange and whether conversion or exchange is mandatory, at the option of the holder or at our option. We may include provisions pursuant to which the number of shares of our common stock or our other securities that the holders of the series of debt securities receive would be subject to adjustment.

Consolidation, Merger or Sale

Unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, the indenture will not contain any covenant that restricts our ability to merge or consolidate, or sell, convey, transfer or otherwise dispose of our assets as an entirety or substantially as an entirety. However, any successor to or acquirer of such assets (other than any subsidiary of ours) must assume all of our obligations under the indenture or the debt securities, as appropriate.

Events of Default under the Indenture

Unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, the following are events of default under the indenture with respect to any series of debt securities that we may issue:

∎ if we fail to pay any installment of interest on any series of debt securities, as and when the same shall become due and payable, and such default continues for a period of 90 days; provided, however, that a valid extension of an interest payment period by us in accordance with the terms of any indenture supplemental thereto shall not constitute a default in the payment of interest for this purpose;

∎ if we fail to pay the principal of, or premium, if any, on any series of debt securities as and when the same shall become due and payable whether at maturity, upon redemption, by declaration or otherwise, or in any payment required by any sinking or analogous fund established with respect to such series; provided, however, that a valid extension of the maturity of such debt securities in accordance with the terms of any indenture supplemental thereto shall not constitute a default in the payment of principal or premium, if any;

∎ if we fail to observe or perform any other covenant or agreement contained in the debt securities or the indenture, other than a covenant specifically relating to another series of debt securities, and our failure continues for 90 days after we receive written notice of such failure, requiring the same to be remedied and stating that such is a notice of default thereunder, from the trustee or holders of at least 25% in aggregate principal amount of the outstanding debt securities of the applicable series; and

∎ if specified events of bankruptcy, insolvency or reorganization occur.

If an event of default with respect to debt securities of any series occurs and is continuing, other than an event of default specified in the last bullet point above, the trustee or the holders of at least 25% in aggregate principal amount of the outstanding debt securities of that series, by notice to us in writing, and to the trustee if notice is given by such holders, may declare the unpaid principal of, premium, if any, and accrued interest, if any, due and payable immediately. If an event of default specified in the last bullet point above occurs with respect to us, the principal amount of and accrued interest, if any, of each issue of debt securities then outstanding shall be due and payable without any notice or other action on the part of the trustee or any holder.

The holders of a majority in principal amount of the outstanding debt securities of an affected series may waive any default or event of default with respect to the series and its consequences, except defaults or events of default regarding payment of principal, premium, if any, or interest, unless we have cured the default or event of default in accordance with the indenture. Any waiver shall cure the default or event of default.

Subject to the terms of the indenture, if an event of default under an indenture shall occur and be continuing, the trustee will be under no obligation to exercise any of its rights or powers under such indenture at the request or direction of any of the holders of the applicable series of debt securities, unless such holders have offered the trustee reasonable indemnity. The holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available

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to the trustee, or exercising any trust or power conferred on the trustee, with respect to the debt securities of that series, provided that:

∎ the direction so given by the holder is not in conflict with any law or the applicable indenture; and

∎ subject to its duties under the Trust Indenture Act, the trustee need not take any action that might involve it in personal liability or might be unduly prejudicial to the holders not involved in the proceeding.

A holder of the debt securities of any series will have the right to institute a proceeding under the indenture or to appoint a receiver or trustee, or to seek other remedies only if:

∎ the holder has given written notice to the trustee of a continuing event of default with respect to that series;

∎ the holders of at least 25% in aggregate principal amount of the outstanding debt securities of that series have made written request;

∎ such holders have offered to the trustee indemnity satisfactory to it against the costs, expenses and liabilities to be incurred by the trustee in compliance with the request; and

∎ the trustee does not institute the proceeding, and does not receive from the holders of a majority in aggregate principal amount of the outstanding debt securities of that series other conflicting directions within 90 days after the notice, request and offer.

These limitations do not apply to a suit instituted by a holder of debt securities if we default in the payment of the principal, premium, if any, or interest on, the debt securities.

We will periodically file statements with the trustee regarding our compliance with specified covenants in the indenture.

Modification of Indenture; Waiver

We and the trustee may change an indenture without the consent of any holders with respect to specific matters:

∎ to cure any ambiguity, defect or inconsistency in the indenture or in the debt securities of any series;

∎ to comply with the provisions described above under “Description of Debt Securities—Consolidation, Merger or Sale”;

∎ to provide for uncertificated debt securities in addition to or in place of certificated debt securities;

∎ to add to our covenants, restrictions, conditions or provisions such new covenants, restrictions, conditions or provisions for the benefit of the holders of all or any series of debt securities, to make the occurrence, or the occurrence and the continuance, of a default in any such additional covenants, restrictions, conditions or provisions an event of default or to surrender any right or power conferred upon us in the indenture;

∎ to add to, delete from or revise the conditions, limitations, and restrictions on the authorized amount, terms, or purposes of issue, authentication and delivery of debt securities, as set forth in the indenture;

∎ to make any change that does not adversely affect the interests of any holder of debt securities of any series in any material respect;

∎ to provide for the issuance of and establish the form and terms and conditions of the debt securities of any series as provided above under “Description of Debt Securities—General” to establish the form of any certifications required to be furnished pursuant to the terms of the indenture or any series of debt securities, or to add to the rights of the holders of any series of debt securities;

∎ to evidence and provide for the acceptance of appointment under any indenture by a successor trustee; or

∎ to comply with any requirements of the SEC in connection with the qualification of any indenture under the Trust Indenture Act.

In addition, under the indenture, the rights of holders of a series of debt securities may be changed by us and the trustee with the written consent of the holders of at least a majority in aggregate principal amount of the outstanding debt securities of each series that is affected. However, unless we provide otherwise in the prospectus supplement

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applicable to a particular series of debt securities, we and the trustee may make the following changes only with the consent of each holder of any outstanding debt securities affected:

∎ extending the fixed maturity of any debt securities of any series;

∎ reducing the principal amount, reducing the rate of or extending the time of payment of interest, or reducing any premium payable upon the redemption of any series of any debt securities; or

∎ reducing the percentage of debt securities, the holders of which are required to consent to any amendment, supplement, modification or waiver.

Discharge

Each indenture provides that we can elect to be discharged from our obligations with respect to one or more series of debt securities, except for specified obligations, including obligations to:

∎ provide for payment;

∎ register the transfer or exchange of debt securities of the series;

∎ replace stolen, lost or mutilated debt securities of the series;

∎ pay principal of and premium and interest on any debt securities of the series;

∎ maintain paying agencies;

∎ hold monies for payment in trust;

∎ recover excess money held by the trustee;

∎ compensate and indemnify the trustee; and

∎ appoint any successor trustee.

In order to exercise our rights to be discharged, we must deposit with the trustee money or government obligations sufficient to pay all the principal of, any premium, if any, and interest on, the debt securities of the series on the dates payments are due.

Form, Exchange and Transfer

We will issue the debt securities of each series only in fully registered form without coupons and, unless we provide otherwise in the applicable prospectus supplement, in denominations of $1,000 and any integral multiple thereof. The indenture provides that we may issue debt securities of a series in temporary or permanent global form and as book-entry securities that will be deposited with, or on behalf of, The Depository Trust Company (“DTC”) or another depositary named by us and identified in the applicable prospectus supplement with respect to that series. To the extent the debt securities of a series are issued in global form and as book-entry, a description of terms relating to any book-entry securities will be set forth in the applicable prospectus supplement.

At the option of the holder, subject to the terms of the indenture and the limitations applicable to global securities described in the applicable prospectus supplement, the holder of the debt securities of any series can exchange the debt securities for other debt securities of the same series, in any authorized denomination and of like tenor and aggregate principal amount.

Subject to the terms of the indenture and the limitations applicable to global securities set forth in the applicable prospectus supplement, holders of the debt securities may present the debt securities for exchange or for registration of transfer, duly endorsed or with the form of transfer endorsed thereon duly executed if so required by us or the security registrar, at the office of the security registrar or at the office of any transfer agent designated by us for this purpose. Unless otherwise provided in the debt securities that the holder presents for transfer or exchange, we will impose no service charge for any registration of transfer or exchange, but we may require payment of any taxes or other governmental charges.

We will name in the applicable prospectus supplement the security registrar, and any transfer agent in addition to the security registrar, that we initially designate for any debt securities. We may at any time designate additional transfer agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for the debt securities of each series.

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If we elect to redeem the debt securities of any series, we will not be required to:

∎ issue, register the transfer of, or exchange any debt securities of that series during a period beginning at the opening of business 15 days before the day of mailing of a notice of redemption of any debt securities that may be selected for redemption and ending at the close of business on the day of the mailing; or

∎ register the transfer of or exchange any debt securities so selected for redemption, in whole or in part, except the unredeemed portion of any debt securities we are redeeming in part.

Information Concerning the Trustee

The trustee, other than during the occurrence and continuance of an event of default under an indenture, undertakes to perform only those duties as are specifically set forth in the applicable indenture. Upon an event of default under an indenture, the trustee must use the same degree of care as a prudent person would exercise or use in the conduct of his or her own affairs. Subject to this provision, the trustee is under no obligation to exercise any of the powers given it by the indenture at the request of any holder of debt securities unless it is offered reasonable security and indemnity against the costs, expenses and liabilities that it might incur.

Payment and Paying Agents

Unless we otherwise indicate in the applicable prospectus supplement, we will make payment of the interest on any debt securities on any interest payment date to the person in whose name the debt securities, or one or more predecessor securities, are registered at the close of business on the regular record date for the interest.

We will pay principal of and any premium and interest on the debt securities of a particular series at the office of the paying agents designated by us, except that unless we otherwise indicate in the applicable prospectus supplement, we will make interest payments by check that we will mail to the holder or by wire transfer to certain holders. Unless we otherwise indicate in the applicable prospectus supplement, we will designate the corporate trust office of the trustee as our sole paying agent for payments with respect to debt securities of each series. We will name in the applicable prospectus supplement any other paying agents that we initially designate for the debt securities of a particular series. We will maintain a paying agent in each place of payment for the debt securities of a particular series.

All money we pay to a paying agent or the trustee for the payment of the principal of or any premium or interest on any debt securities that remains unclaimed at the end of two years after such principal, premium or interest has become due and payable will be repaid to us, and the holder of the debt security thereafter may look only to us for payment thereof.

Governing Law

The indenture and the debt securities will be governed by and construed in accordance with the laws of the state of New York, except to the extent that the Trust Indenture Act is applicable.

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DESCRIPTION OF WARRANTS

The following description, together with the additional information we may include in any applicable prospectus supplements, summarizes the material terms and provisions of the warrants that we may offer under this prospectus and the related warrant agreements and warrant certificates. While the terms summarized below will apply generally to any warrants that we may offer, we will describe the particular terms of any series of warrants in more detail in the applicable prospectus supplement. If we indicate in the prospectus supplement, the terms of any warrants offered under that prospectus supplement may differ from the terms described below. Specific warrant agreements will contain additional important terms and provisions and will be incorporated by reference as an exhibit to the registration statement, which includes this prospectus.

General

We may issue warrants for the purchase of common stock, preferred stock and/or debt securities in one or more series. We may issue warrants independently or together with common stock, preferred stock and debt securities, and the warrants may be attached to or separate from these securities.

We will evidence each series of warrants by warrant certificates that we will issue under a separate warrant agreement. We will enter into the warrant agreement with a warrant agent. We will indicate the name and address of the warrant agent in the applicable prospectus supplement relating to a particular series of warrants.

We will describe in the applicable prospectus supplement the terms of the series of warrants, including:

∎ the offering price and aggregate number of warrants offered;

∎ the currency for which the warrants may be purchased;

∎ if applicable, the designation and terms of the securities with which the warrants are issued and the number of warrants issued with each such security or each principal amount of such security;

∎ if applicable, the date on and after which the warrants and the related securities will be separately transferable;

∎ in the case of warrants to purchase common stock or preferred stock, the number of shares of common stock or preferred stock, as the case may be, purchasable upon the exercise of one warrant and the price at which these shares may be purchased upon such exercise;

∎ in the case of warrants to purchase debt securities, the principal amount of debt securities purchasable upon exercise of one warrant and the price at, and currency in which, this principal amount of debt securities may be purchased upon such exercise;

∎ the effect of any merger, consolidation, sale or other disposition of our business on the warrant agreement and the warrants;

∎ the terms of any rights to redeem or call the warrants;

∎ any provisions for changes to or adjustments in the exercise price or number of securities issuable upon exercise of the warrants;

∎ the periods during which, and places at which, the warrants are exercisable;

∎ the manner of exercise;

∎ the dates on which the right to exercise the warrants will commence and expire;

∎ the manner in which the warrant agreement and warrants may be modified;

∎ federal income tax consequences of holding or exercising the warrants;

∎ the terms of the securities issuable upon exercise of the warrants; and

∎ any other specific terms, preferences, rights or limitations of or restrictions on the warrants.

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DESCRIPTION OF UNITS

We may issue units comprised of one or more of the other securities that may be offered under this prospectus, in any combination. We may issue units in such amounts and in as many distinct series as we wish. This section outlines certain provisions of the units that we may issue. If we issue units, they will be issued under one or more unit agreements to be entered into between us and a bank or other financial institution, as unit agent. The information described in this section may not be complete in all respects and is qualified entirely by reference to the unit agreement with respect to the units of any particular series. The specific terms of any series of units offered will be described in the applicable prospectus supplement. If so described in a particular supplement, the specific terms of any series of units may differ from the general description of terms presented below. We urge you to read any prospectus supplement related to any series of units we may offer, as well as the complete unit agreement and unit certificate that contain the terms of the units. If we issue units, forms of unit agreements and unit certificates relating to such units will be incorporated by reference as exhibits to the registration statement, which includes this prospectus.

Each unit that we may issue will be issued so that the holder of the unit is also the holder of each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each included security. The unit agreement under which a unit is issued may provide that the securities included in the unit may not be held or transferred separately, at any time or at any time before a specified date. The applicable prospectus supplement may describe:

∎ the designation and terms of the units and of the securities comprising the units, including whether and under what circumstances those securities may be held or transferred separately;

∎ any provisions of the governing unit agreement;

∎ the price or prices at which such units will be issued;

∎ the applicable United States federal income tax considerations relating to the units;

∎ any provisions for the issuance, payment, settlement, transfer or exchange of the units or of the securities comprising the units; and

∎ any other terms of the units and of the securities comprising the units.

The provisions described in this section, as well as those described under “Description of Capital Stock,” and “Description of Warrants” will apply to the securities included in each unit, to the extent relevant and as may be updated in any prospectus supplements.

Issuance in Series

We may issue units in such amounts and in as many distinct series as we wish. This section summarizes terms of the units that apply generally to all series. Most of the financial and other specific terms of a particular series of units will be described in the applicable prospectus supplement.

Unit Agreements

We will issue the units under one or more unit agreements to be entered into between us and a bank or other financial institution, as unit agent. We may add, replace or terminate unit agents from time to time. We will identify the unit agreement under which each series of units will be issued and the unit agent under that agreement in the applicable prospectus supplement.

The following provisions will generally apply to all unit agreements unless otherwise stated in the applicable prospectus supplement:

Modification without Consent

We and the applicable unit agent may amend any unit or unit agreement without the consent of any holder:

∎ to cure any ambiguity;

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∎ any provisions of the governing unit agreement that differ from those described below;

∎ to correct or supplement any defective or inconsistent provision; or

∎ to make any other change that we believe is necessary or desirable and will not adversely affect the interests of the affected holders in any material respect.

We do not need any approval to make changes that affect only units to be issued after the changes take effect. We may also make changes that do not adversely affect a particular unit in any material respect, even if they adversely affect other units in a material respect. In those cases, we do not need to obtain the approval of the holder of the unaffected unit; we need only obtain any required approvals from the holders of the affected units.

Modification with Consent

We may not amend any particular unit or a unit agreement with respect to any particular unit unless we obtain the consent of the holder of that unit, if the amendment would:

∎ impair any right of the holder to exercise or enforce any right under a security included in the unit if the terms of that security require the consent of the holder to any changes that would impair the exercise or enforcement of that right; or

∎ reduce the percentage of outstanding units or any series or class the consent of whose holders is required to amend that series or class, or the applicable unit agreement with respect to that series or class, as described below.

Any other change to a particular unit agreement and the units issued under that agreement would require the following approval:

∎ If the change affects only the units of a particular series issued under that agreement, the change must be approved by the holders of a majority of the outstanding units of that series; or

∎ If the change affects the units of more than one series issued under that agreement, it must be approved by the holders of a majority of all outstanding units of all series affected by the change, with the units of all the affected series voting together as one class for this purpose.

These provisions regarding changes with majority approval also apply to changes affecting any securities issued under a unit agreement, as the governing document.

In each case, the required approval must be given by written consent.

Unit Agreements Will Not Be Qualified under Trust Indenture Act

No unit agreement will be qualified as an indenture, and no unit agent will be required to qualify as a trustee, under the Trust Indenture Act. Therefore, holders of units issued under unit agreements will not have the protections of the Trust Indenture Act with respect to their units.

Mergers and Similar Transactions Permitted; No Restrictive Covenants or Events of Default

The unit agreements will not restrict our ability to merge or consolidate with, or sell our assets to, another corporation or other entity or to engage in any other transactions. If at any time we merge or consolidate with, or sell our assets substantially as an entirety to, another corporation or other entity, the successor entity will succeed to and assume our obligations under the unit agreements. We will then be relieved of any further obligation under these agreements.

The unit agreements will not include any restrictions on our ability to put liens on our assets, nor will they restrict our ability to sell our assets. The unit agreements also will not provide for any events of default or remedies upon the occurrence of any events of default.

Governing Law

The unit agreements and the units will be governed by New York law.

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Form, Exchange and Transfer

We will issue each unit in global—i.e., book-entry—form only. Units in book-entry form will be represented by a global security registered in the name of a depositary, which will be the holder of all the units represented by the global security. Those who own beneficial interests in a unit will do so through participants in the depositary’s system, and the rights of these indirect owners will be governed solely by the applicable procedures of the depositary and its participants. We will describe book-entry securities, and other terms regarding the issuance and registration of the units in the applicable prospectus supplement.

Each unit and all securities comprising the unit will be issued in the same form.

If we issue any units in registered, non-global form, the following will apply to them.

The units will be issued in the denominations stated in the applicable prospectus supplement. Holders may exchange their units for units of smaller denominations or combined into fewer units of larger denominations, as long as the total amount is not changed.

∎ Holders may exchange or transfer their units at the office of the unit agent. Holders may also replace lost, stolen, destroyed or mutilated units at that office. We may appoint another entity to perform these functions or perform them ourselves.

∎ Holders will not be required to pay a service charge to transfer or exchange their units, but they may be required to pay for any tax or other governmental charge associated with the transfer or exchange. The transfer or exchange, and any replacement, will be made only if our transfer agent is satisfied with the holder’s proof of legal ownership. The transfer agent may also require an indemnity before replacing any units.

∎ If we have the right to redeem, accelerate or settle any units before their maturity, and we exercise our right as to less than all those units or other securities, we may block the exchange or transfer of those units during the period beginning 15 days before the day we mail the notice of exercise and ending on the day of that mailing, in order to freeze the list of holders to prepare the mailing. We may also refuse to register transfers of or exchange any unit selected for early settlement, except that we will continue to permit transfers and exchanges of the unsettled portion of any unit being partially settled. We may also block the transfer or exchange of any unit in this manner if the unit includes securities that are or may be selected for early settlement.

Only the depositary will be entitled to transfer or exchange a unit in global form, since it will be the sole holder of the unit.

Payments and Notices

In making payments and giving notices with respect to our units, we will follow the procedures as described in the applicable prospectus supplement.

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PLAN OF DISTRIBUTION

We may sell the securities offered through this prospectus and any accompanying prospectus supplement, if required, in any of the following ways: (i) to or through underwriters or dealers, (ii) directly to purchasers, including our affiliates, (iii) through agents, (iv) in an “at the market offering,” within the meaning of Rule 415(a)(4) of the Securities Act, to or through market makers or into an existing market for the securities; or (v) through a combination of any of these methods or any other method permitted by law. The securities may be distributed at a fixed price or prices, which may be changed, market prices prevailing at the time of sale, prices related to the prevailing market prices, or negotiated prices, either:

∎ on or through the facilities of The Nasdaq Global Market or any other securities exchange or quotation or trading service on which such securities may be listed, quoted or traded at the time of sale; and/or

∎ to or through a market maker otherwise than on The Nasdaq Global Market or such other securities exchanges or quotation or trading services.

In addition, we may issue the securities as a dividend or distribution or in a subscription rights offering to our existing security holders.

We may directly solicit offers to purchase securities, or agents may be designated to solicit such offers. In the prospectus supplement relating to such offering, we will name any agent that could be viewed as an underwriter under the Securities Act and describe any commissions that we must pay to any such agent. Any such agent will be acting on a best efforts basis for the period of its appointment or, if indicated in the applicable prospectus supplement, on a firm commitment basis. This prospectus may be used in connection with any offering of our securities through any of these methods or other methods described in the applicable prospectus supplement.

The distribution of the securities may be effected from time to time in one or more transactions:

∎ at a fixed price, or prices, which may be changed from time to time;

∎ at market prices prevailing at the time of sale;

∎ at prices related to such prevailing market prices; or

∎ at negotiated prices.

Each prospectus supplement will describe the method of distribution of the securities and any applicable restrictions.

The prospectus supplement with respect to the securities of a particular series will describe the terms of the offering of the securities, including the following:

∎ the name of the agent or any underwriters;

∎ the public offering or purchase price;

∎ any discounts and commissions to be allowed or paid to the agent or underwriters;

∎ all other items constituting underwriting compensation;

∎ any discounts and commissions to be allowed or paid to dealers; and

∎ any exchanges on which the securities will be listed.

If any underwriters or agents are used in the sale of the securities in respect of which this prospectus is delivered, we will enter into an underwriting agreement, sale agreement or other agreement with them at the time of sale to them, and we will set forth in the prospectus supplement relating to such offering the names of the underwriters or agents and the terms of the related agreement with them.

In connection with the offering of securities, we may grant to the underwriters an option to purchase additional securities with an additional underwriting commission, as may be set forth in the accompanying prospectus supplement. If we grant any such option, the terms of such option will be set forth in the prospectus supplement for such securities.

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If a dealer is used in the sale of the securities in respect of which the prospectus is delivered, we will sell such securities to the dealer, as principal. The dealer, who may be deemed to be an “underwriter” as that term is defined in the Securities Act, may then resell such securities to the public at varying prices to be determined by such dealer at the time of resale.

If we offer securities in a subscription rights offering to our existing security holders, we may enter into a standby underwriting agreement with dealers, acting as standby underwriters. We may pay the standby underwriters a commitment fee for the securities they commit to purchase on a standby basis. If we do not enter into a standby underwriting arrangement, we may retain a dealer-manager to manage a subscription rights offering for us.

Agents, underwriters, dealers and other persons may be entitled under agreements which they may enter into with us to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, and may be customers of, engage in transactions with or perform services for us in the ordinary course of business.

If so indicated in the applicable prospectus supplement, we will authorize underwriters or other persons acting as our agents to solicit offers by certain institutions to purchase securities from us pursuant to delayed delivery contracts providing for payment and delivery on the date stated in the prospectus supplement. Each contract will be for an amount not less than, and the aggregate amount of securities sold pursuant to such contracts shall not be less nor more than, the respective amounts stated in the prospectus supplement. Institutions with whom the contracts, when authorized, may be made include commercial and savings banks, insurance companies, pension funds, investment companies, educational and charitable institutions and other institutions, but shall in all cases be subject to our approval. Delayed delivery contracts will not be subject to any conditions except that:

∎ the purchase by an institution of the securities covered under that contract shall not at the time of delivery be prohibited under the laws of the jurisdiction to which that institution is subject; and

∎ if the securities are also being sold to underwriters acting as principals for their own account, the underwriters shall have purchased such securities not sold for delayed delivery. The underwriters and other persons acting as our agents will not have any responsibility in respect of the validity or performance of delayed delivery contracts.

Offered securities may also be offered and sold, if so indicated in the prospectus supplement, in connection with a remarketing upon their purchase, in accordance with a redemption or repayment pursuant to their terms, or otherwise, by one or more remarketing firms, acting as principals for their own accounts or as agents for us. Any remarketing firm will be identified and the terms of its agreement, if any, with us and its compensation will be described in the applicable prospectus supplement. Remarketing firms may be deemed to be underwriters in connection with their remarketing of offered securities.

Certain agents, underwriters and dealers, and their associates and affiliates, may be customers of, have borrowing relationships with, engage in other transactions with, or perform services, including investment banking services, for us or one or more of our respective affiliates in the ordinary course of business.

In order to facilitate the offering of the securities, any underwriters may engage in transactions that stabilize, maintain or otherwise affect the price of the securities or any other securities the prices of which may be used to determine payments on such securities. Specifically, any underwriters may overallot in connection with the offering, creating a short position for their own accounts. In addition, to cover overallotments or to stabilize the price of the securities or of any such other securities, the underwriters may bid for, and purchase, the securities or any such other securities in the open market. Finally, in any offering of the securities through a syndicate of underwriters, the underwriting syndicate may reclaim selling concessions allowed to an underwriter or a dealer for distributing the securities in the offering if the syndicate repurchases previously distributed securities in transactions to cover syndicate short positions, in stabilization transactions or otherwise. Any of these activities may stabilize or maintain the market price of the securities above independent market levels. Any such underwriters are not required to engage in these activities and may end any of these activities at any time.

We may engage in at the market offerings into an existing trading market in accordance with Rule 415(a)(4) under the Securities Act. In addition, we may enter into derivative transactions with third parties, or sell securities not

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covered by this prospectus to third parties in negotiated transactions. If the applicable prospectus supplement so indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including in short sale transactions. If so, the third party may use securities pledged by us or borrowed from us or others to settle those sales or to close out any related open borrowings of stock, and may use securities received from us in settlement of those derivatives to close out any related open borrowings of stock. The third party in such sale transactions will be an underwriter and, if not identified in this prospectus, will be named in the applicable prospectus supplement (or a post-effective amendment). In addition, we may otherwise loan or pledge securities to a financial institution or other third party that in turn may sell the securities short using this prospectus and an applicable prospectus supplement. Such financial institution or other third party may transfer its economic short position to investors in our securities or in connection with a concurrent offering of other securities.

Under Rule 15c6-1 of the Exchange Act, trades in the secondary market generally are required to settle in one business day, unless the parties to any such trade expressly agree otherwise. The applicable prospectus supplement may provide that the original issue date for your securities may be more than one scheduled business day after the trade date for your securities. Accordingly, in such a case, if you wish to trade securities on any date prior to the first business day before the original issue date for your securities, you will be required, by virtue of the fact that your securities initially are expected to settle in more than one scheduled business day after the trade date for your securities, to make alternative settlement arrangements to prevent a failed settlement.

The securities may be new issues of securities and may have no established trading market, other than the shares of Common Stock, which are listed on Nasdaq Global Market. The securities may or may not be listed on a national securities exchange. We can make no assurance as to the liquidity of or the existence of trading markets for any of the securities.

The specific terms of any lock-up provisions in respect of any given offering will be described in the applicable prospectus supplement.

Any underwriters, dealers and agents may engage in transactions with us, or perform services for us, in the ordinary course of business for which they receive compensation.

The anticipated date of delivery of offered securities will be set forth in the applicable prospectus supplement relating to each offer.

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LEGAL MATTERS

Unless the applicable prospectus supplement indicates otherwise, the validity of the securities in respect of which this prospectus is being delivered will be passed upon by Goodwin Procter LLP, Boston, Massachusetts. Additional legal matters may be passed upon for us or any underwriters, dealers or agents, by counsel that we will name in the applicable prospectus supplement.

EXPERTS

The financial statements and management’s assessment of the effectiveness of internal control over financial reporting (which is included in Management’s Report on Internal Control Over Financial Reporting) incorporated in this Prospectus by reference to the Annual Report on Form 10-K for the year ended December 31, 2024 have been so incorporated in reliance on the report (which contains an explanatory paragraph relating to the Company’s incurrence of significant operating losses and expectation to continue generating operating losses and negative cash flows from operations for the foreseeable future as described in Note 1 to the financial statements) of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at www.sec.gov and on our investor website at https://ir.tangotx.com/. Our website is not a part of this prospectus and is not incorporated by reference in this prospectus.

We have the authority to designate and issue more than one class or series of stock having various preferences, conversion and other rights, voting powers, restrictions, limitations as to dividends, qualifications, and terms and conditions of redemption. See “Description of Capital Stock.” We will furnish a full statement of the relative rights and preferences of each class or series of our stock which has been so designated and any restrictions on the ownership or transfer of our stock to any stockholder upon request and without charge. Written requests for such copies should be directed to Tango Therapeutics, Inc., 201 Brookline Avenue, Suite 901, Boston, MA 02215, Attention: Corporate Secretary.

This prospectus is part of a registration statement on Form S-3 we filed with the SEC. This prospectus omits some information contained in the registration statement in accordance with SEC rules and regulations. You should review the information and exhibits in the registration statement for further information about us and our consolidated subsidiaries and the securities we are offering. Statements in this prospectus concerning any document we filed as an exhibit to the registration statement or that we otherwise filed with the SEC are not intended to be comprehensive and are qualified by reference to these filings. You should review the complete document to evaluate these statements.

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INCORPORATION BY REFERENCE

The SEC allows us to incorporate by reference much of the information we file with the SEC, which means that we can disclose important information to you by referring you to those publicly available documents. The information that we incorporate by reference in this prospectus is considered to be part of this prospectus. Because we are incorporating by reference future filings with the SEC, this prospectus is continually updated and those future filings may modify or supersede some of the information included or incorporated in this prospectus. This means that you must look at all of the SEC filings that we incorporate by reference to determine if any of the statements in this prospectus or in any document previously incorporated by reference have been modified or superseded. This prospectus incorporates by reference the documents listed below and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) (in each case, other than those documents or the portions of those documents not deemed to be filed) between the date of the initial registration statement and the effectiveness of the registration statement and following the effectiveness of the registration statement until the offering of the securities under the registration statement is terminated or completed:

∎ Annual Report on Form 10-K for the fiscal year ended December 31, 2024, filed with the SEC on February 27, 2025;

∎ The information specifically incorporated by reference into our Annual Report on Form 10-K for the year ended December  31, 2024 from our amended definitive proxy statement on Schedule 14A (other than information furnished rather than filed) filed with the SEC on April 24, 2025;

∎ Quarterly Report on Form 10-Q for the quarter ended March 31, 2025, filed with the SEC on May 12, 2025; and

∎ The description of our common stock contained in our Registration Statement on Form 8-A filed on September  2, 2020, including any amendments or reports filed for the purpose of updating such description, including Exhibit 4.2 to our Annual Report on Form 10-K for the year ended December 31, 2024.

This prospectus is part of a registration statement we filed with the SEC. We have incorporated exhibits into this registration statement. You should read the exhibits carefully for provisions that may be important to you.

In addition, all reports and other documents filed by us pursuant to the Exchange Act after the date of the initial registration statement and prior to effectiveness of the registration statement shall be deemed to be incorporated by reference into this prospectus.

Notwithstanding the foregoing, unless specifically stated to the contrary, information that we furnish (and that is not deemed “filed” with the SEC) under Items 2.02 and 7.01 of any Current Report on Form 8-K, including the related exhibits under Item 9.01, is not incorporated by reference into this prospectus or the registration statement of which this prospectus is a part.

You may request a copy of these filings, at no cost, by writing or telephoning us at the following address or telephone number:

201 Brookline Avenue, Suite 901

Boston, MA 02215

Attn: Corporate Secretary

(857) 320-4900

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Tango Therapeutics, Inc.

21,023,337 Shares of Common Stock

Pre-funded Warrants to Purchase 3,226,458 Shares of Common Stock

Prospectus Supplement

Leerink Partners Cantor

October 23, 2025

FAQ

What is Tango Therapeutics (TNGX) offering in this transaction?

The company is offering 21,023,337 shares of common stock and pre-funded warrants to purchase up to 3,226,458 shares, with warrant shares also covered.

What are the offering prices for TNGX securities?

Common stock is priced at $8.66 per share and pre-funded warrants at $8.659 per warrant, with a $0.001 per-share exercise price.

How much will TNGX receive in proceeds?

Estimated net proceeds are $197,399,805 before expenses from the public offering. Total offering price is $209,999,998.

Is there a concurrent private placement (PIPE) for TNGX?

Yes. Tango agreed to sell 1,732,101 shares at $8.66 per share in a PIPE exempt from registration; this offering is not conditioned on the PIPE.

How will Tango use the proceeds and how long will funding last?

Tango intends to advance its pipeline and for general corporate purposes, stating combined funds are expected to support operations into 2028.

What is TNGX’s cash position cited in the document?

The company estimates cash, cash equivalents and marketable securities of approximately $152.8 million as of September 30, 2025.

When is the expected delivery date for the offering?

The underwriter expects to deliver the securities on or about October 24, 2025.