Verastem may sell up to $100M in at-the-market offering

Verastem, Inc. (VSTM) may offer and sell common stock with an aggregate offering price of up to $100,000,000 from time to time through Cantor Fitzgerald & Co. in an at-the-market offering.

Available on EDGAR 11/05/2026 - 05:23 PM EST Accepted by SEC EDGAR 11/05/2026 - 05:23 PM EST Learn about SEC filing dates

Rhea-AI Filing Summary

Verastem, Inc. (VSTM) may offer and sell common stock with an aggregate offering price of up to $100,000,000 from time to time through Cantor Fitzgerald & Co. in an at-the-market offering. If Verastem receives all $100,000,000 in gross proceeds, it anticipates net proceeds of approximately $97.6 million after estimated commissions and expenses. Cantor will act as sales agent on a best-efforts basis and may receive commissions of up to 3.0% of the gross sales price per share sold.

Verastem intends to use net proceeds for commercial activities for AVMAPKI FAKZYNJA CO-PACK, continued clinical development of VS-7375, research and development of other product candidates, working capital and other general corporate purposes, which may include possible acquisitions.

Filing Explained

The full-sale scenario is 10,152,284 shares at $9.85 each, but the filing does not commit Verastem to issue that amount.

Verastem says it sold no shares under its prior ATM prospectus before terminating it on October 14, 2026, and this filing sets up a new prospectus for sales under the same Cantor agreement; sales remain optional, but issuing shares would increase the share count and reduce existing holders’ percentage ownership.

At the filing’s assumed $9.85 per share, a full $100 million sale would involve 10,152,284 shares; the actual number depends on sale prices.

The new prospectus permits sales under the ATM but does not report that those shares have been sold.

Key Figures

Aggregate offering price: Up to $100,000,000 Anticipated net proceeds: Approximately $97.6 million Cantor commission: Up to 3.0% +2 more

5 metrics

Aggregate offering price Up to $100,000,000 Common stock offered through the at-the-market offering

Anticipated net proceeds Approximately $97.6 million If Verastem receives all $100,000,000 of gross proceeds, after estimated commissions and expenses

Cantor commission Up to 3.0% Of the gross sales price per share sold

Last reported sale price $9.85 per share November 4, 2026

Shares in assumed offering 10,152,284 shares Assumes an offering price of $9.85 per share; actual shares issued will vary with sales prices

Key Terms

at-the-market equity offerings, best efforts basis, aggregate offering price, underwriter

4 terms

at-the-market equity offerings financial

"sales deemed to be “at-the-market” equity offerings"

A method companies use to raise money by selling newly issued shares directly into the open market over time at the current market price, rather than all at once in a single big sale. Think of it like a store restocking and selling extra items gradually so prices stay closer to normal; for investors it matters because it can increase the number of shares outstanding and slowly dilute existing ownership while providing the company with flexible funding without a large, sudden market shock.

best efforts basis financial

"Cantor will act as sales agent on a best efforts basis"

An agreement executed on a best efforts basis requires a party—often an underwriter or seller—to try hard to complete a transaction but does not guarantee the result. Think of it like a real estate agent who promises to do their utmost to find a buyer but cannot promise a sale; investors care because outcomes (like the amount raised or whether securities are sold) are uncertain and depend on market demand rather than a firm commitment.

aggregate offering price financial

"shares of our common stock having an aggregate offering price of up to $100.0 million"

The aggregate offering price is the total dollar amount that will be raised if all the securities in an offering are sold at the stated offering price, before fees or expenses are taken out. Investors use it to gauge the size of the fundraising and its potential effects—such as how much cash the company will get and how much existing ownership might be reduced—similar to totaling every item’s price in a shopping cart to see the full bill.

underwriter regulatory

"Cantor will be deemed to be an “underwriter” within the meaning of the Securities Act"

An underwriter is a financial firm that evaluates, guarantees and helps sell a new security offering—such as a stock or bond—by buying the issue from the issuer and reselling it to investors or organizing the sale. Think of them as a bridge or safety net: they take on the risk, set the price, handle marketing and paperwork, and their work determines how much money a company can raise and how smoothly the offering reaches the market.

Offering Details

ATM · Up to $100,000,000 aggregate offering price

Offering

Offering Type ATM

Securities Offered Common stock

Offering Amount Up to $100,000,000 aggregate offering price

Use of Proceeds Net proceeds are intended to fund commercial activities for AVMAPKI FAKZYNJA CO-PACK, continued clinical development of VS-7375, continued clinical research and development of other product candidates, working capital and other general corporate purposes.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

How much common stock can VSTM sell in its ATM offering?

Verastem may offer and sell common stock with an aggregate offering price of up to $100,000,000 through Cantor Fitzgerald & Co. in an at-the-market offering. Sales may occur from time to time under the sales agreement.

How much net proceeds does VSTM expect from the offering?

If Verastem receives all $100,000,000 of gross proceeds, it anticipates net proceeds of approximately $97.6 million after estimated commissions and expenses payable by the company.

How does VSTM plan to use the ATM proceeds?

Verastem intends to use net proceeds for commercial activities for AVMAPKI FAKZYNJA CO-PACK, continued clinical development of VS-7375, continued clinical research and development of other product candidates, working capital and other general corporate purposes.

What commission may Cantor receive on VSTM ATM sales?

Cantor may receive a commission of up to 3.0% of the gross sales price per share sold. It will act as sales agent on a best-efforts basis and use commercially reasonable efforts to sell shares Verastem requests to be sold, on mutually agreed terms.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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As filed with the Securities and Exchange Commission on November 5, 2026​

Registration No. 333-      ​

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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

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FORM S-3

REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933

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VERASTEM, INC.

(Exact name of registrant as specified in its charter)​

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​ Delaware (State or other jurisdiction
of incorporation or organization) ​ ​ 27-3269467 (I.R.S. Employer
Identification No.) ​

117 Kendrick Street, Suite 500
Needham, Massachusetts 02494
(781) 292-4200
(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Daniel W. Paterson
Chief Executive Officer
Verastem, Inc.
117 Kendrick Street, Suite 500
Needham, Massachusetts 02494
(781) 292-4200
(Name, address, including zip code, and telephone number, including area code, of agent for service)

​

With copies to:
Marko Zatylny
Thomas Danielski
Ropes & Gray LLP
Prudential Tower
800 Boylston St.
Boston, Massachusetts 02199
(617) 951-7000

From time to time after the effectiveness of the registration statement
(Approximate date of commencement of proposed sale to the public)​

​

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box: ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box: ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. ☐

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Securities Exchange Act of 1934 (“Exchange Act”).

​ Large accelerated filer ☐ ​ ​ Accelerated filer ☐ ​ ​ Non-accelerated filer ☒ ​ ​ Smaller reporting company ☒ ​ ​ Emerging growth company ☐ ​

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

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EXPLANATORY NOTE

This registration statement contains the following documents:

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a base prospectus, which covers the offering, issuance and sale by us of an indeterminate amount of the securities identified below from time to time in one or more offerings; and

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an at-the-market offering prospectus supplement covering the offer, issuance and sale of up to a maximum aggregate offering price of $100,000,000 of our common stock that may be issued and sold under our sales agreement with Cantor Fitzgerald & Co., dated August 8, 2025.

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The base prospectus immediately follows this explanatory note. The at-the-market offering prospectus supplement immediately follows the base prospectus. Upon termination of the sales agreement with Cantor Fitzgerald & Co., any amounts included in the at-the-market offering prospectus supplement that remain unsold will be available for sale in other offerings pursuant to the base prospectus, and if no shares are sold under the sales agreement, the full amount of this registration statement may be sold in other offerings pursuant to the base prospectus and a corresponding prospectus supplement.

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PROSPECTUS

Common Stock
Preferred Stock
Warrants
Debt Securities

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We may offer and sell from time to time, in one or more series or issuances and in an amount and on terms that we will determine at the time of the respective offering, any combination of the securities described in this prospectus.

We will provide specific terms of any offering in a supplement to this prospectus. We may amend or supplement this prospectus from time to time by filing amendments or supplements as required. Any prospectus supplement may also add, update, or change information contained in this prospectus. You should carefully read this prospectus and any amendments or prospectus supplements as well as the documents incorporated or deemed to be incorporated by reference in this prospectus before you purchase any of the securities offered hereby.

These securities may be offered and sold in the same offering or in separate offerings; to or through underwriters, dealers, and agents; or directly to purchasers. The names of any underwriters, dealers, or agents involved in the sale of our securities and their compensation will be described in the applicable prospectus supplement.

Our common stock is listed on The Nasdaq Capital Market under the symbol “VSTM.” On November 4, 2026, the last reported sale price of our common stock, par value $0.0001 per share, was $9.85 per share.

Investing in our securities involves a high degree of risk. Before making an investment decision, please read the information under the heading “Risk Factors” on page 4 of this prospectus, in any applicable prospectus supplement, and under similar headings in the other documents that are incorporated by reference into this prospectus.

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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.

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Prospectus dated November 5, 2026

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TABLE OF CONTENTS

​	​	​	Page				​
ABOUT THIS PROSPECTUS	​	​	​	​	1	​	​
ABOUT THE COMPANY	​	​	​	​	3	​	​
RISK FACTORS	​	​	​	​	4	​	​
FORWARD-LOOKING STATEMENTS	​	​	​	​	5	​	​
USE OF PROCEEDS	​	​	​	​	7	​	​
PLAN OF DISTRIBUTION	​	​	​	​	8	​	​
DESCRIPTION OF COMMON STOCK	​	​	​	​	10	​	​
DESCRIPTION OF PREFERRED STOCK	​	​	​	​	11	​	​
DESCRIPTION OF WARRANTS	​	​	​	​	12	​	​
DESCRIPTION OF DEBT SECURITIES	​	​	​	​	13	​	​
WHERE YOU CAN FIND MORE INFORMATION	​	​	​	​	21	​	​
INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE	​	​	​	​	22	​	​
LEGAL MATTERS	​	​	​	​	23	​	​
EXPERTS	​	​	​	​	23	​	​

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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 (the “SEC”) as a “well-known seasoned issuer” as defined under Rule 405 under the Securities Act of 1933, as amended (the “Securities Act”), using a “shelf” registration process. Under this shelf registration process, we may from time to time offer to sell any combination of the securities described in this prospectus in one or more offerings. Each time we sell securities under this prospectus, we will provide a prospectus supplement and, if necessary, a free writing prospectus that will contain specific information about the terms of that offering. The prospectus supplement and, if necessary, a free writing prospectus may also add to, update or change information contained in this prospectus. Accordingly, to the extent inconsistent, the information in this prospectus will be deemed to be modified or superseded by any inconsistent information contained in a prospectus supplement or a free writing prospectus. You should read this prospectus and the applicable prospectus supplement and any free writing prospectus carefully, including all documents incorporated herein and therein by reference, together with the additional information described below under “Where You Can Find More Information” before making an investment in our securities.

This prospectus does not include all of the information that is in the registration statement. We omitted certain parts of the registration statement from this prospectus as permitted by the SEC. We refer you to the registration statement and its exhibits for additional information about us and the securities that may be sold under this prospectus.

We have not authorized any dealer, agent or other person to give any information or to make any representation other than those contained or incorporated by reference in this prospectus and any accompanying prospectus supplement or any free writing prospectus provided in connection with an offering. You must not rely upon any information or representation not contained or incorporated by reference in this prospectus or an accompanying prospectus supplement. This prospectus and the accompanying prospectus supplement, if any, do not constitute an offer to sell or the solicitation of an offer to buy any securities other than the registered securities to which they relate, nor do this prospectus and the accompanying prospectus supplement constitute an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make such offer or solicitation in such jurisdiction. You should not assume that the information contained in this prospectus and any accompanying prospectus supplement, if any, is accurate on any date subsequent to the date set forth on the front of the document or that any information we have incorporated by reference is correct on any date subsequent to the date of the document incorporated by reference, even though this prospectus and any accompanying prospectus supplement are delivered or securities are sold on a later date. Our business, financial condition, results of operations and prospects may have changed since those dates.

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under “Where You Can Find More Information.”

References in this prospectus to “Verastem,” the “Company,” “we,” “us,” “our” or similar terms refer to Verastem, Inc. and our subsidiaries on a consolidated basis, as appropriate, unless we state otherwise or the context otherwise requires. The phrase “this prospectus” refers to this prospectus and any applicable prospectus supplement, unless the context otherwise requires.

Trademarks and Tradenames

The Verastem name and logo are our trademarks. This prospectus and any applicable prospectus supplement and documents incorporated by reference herein and therein contain references to our trademarks and to trademarks belonging to other entities. Each of the other trademarks, trade names and service marks included in this prospectus belongs to its respective holder. Solely for convenience, trademarks, trade names and service marks referred to in this prospectus, including logos, artwork and other visual displays, may appear without the ® or TM symbols, but such references are not intended to indicate in any way that we

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will not assert, to the fullest extent under applicable law, our rights or the rights of the applicable licensor to these trademarks, trade names and service marks. We do not intend our use or display of other entities’ trade names, trademarks or service marks to imply a relationship with, or endorsement or sponsorship of us by, any other entity.

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ABOUT THE COMPANY

We are a biopharmaceutical company committed to the development and commercialization of new medicines to improve the lives of patients diagnosed with rat sarcoma (“RAS”)/ mitogen-activated protein kinase (“MAPK”) pathway-driven cancers. On May 8, 2025, the U.S. Food and Drug Administration approved AVMAPKI FAKZYNJA CO-PACK (avutometinib capsules; defactinib tablets) for the treatment of adult patients with Kirsten rat sarcoma viral oncogene homolog (“KRAS”) mutant recurrent low-grade serous ovarian cancer who received prior systemic therapy. We market AVMAPKI FAKZYNJA CO-PACK in the United States. Our pipeline is focused on novel small molecule drugs that inhibit critical signaling pathways in cancer that promote cancer cell survival and tumor growth, including RAF/MEK inhibition, FAK inhibition and KRAS G12D inhibition.

AVMAPKI (avutometinib) inhibits MEK kinase activity while also blocking the compensatory reactivation of MEK by upstream RAF. RAF and MEK proteins are regulators of the RAS/RAF/MEK/​ERK (MAPK) pathway. Blocking RAF and/or MEK activates FAK, a key mediator of drug resistance. FAKZYNJA (defactinib) is a FAK inhibitor, and together, the avutometinib and defactinib combination was designed to provide a more complete blockade of the signaling that drives the growth and drug resistance of RAS/MAPK pathway-dependent tumors.

For our clinical-stage pipeline programs, we are evaluating VS-7375, a potential best-in-class oral KRAS G12D (ON/OFF) inhibitor, for the treatment of patients with KRAS G12D-mutated cancers, including pancreatic ductal adenocarcinoma (“PDAC”), non-small cell lung cancer (“NSCLC”), colorectal cancer (“CRC”) and other KRAS G12D-mutated cancers. Based on preclinical data, VS-7375 offers dual, potent inhibition of both ON and OFF states of KRAS G12D. We believe this correlates with better in vivo efficacy and durability versus ON-only RAS inhibitors. VS-7375 has demonstrated a high affinity for KRAS G12D with a long residence time (18 – 24 hours) in preclinical models. We believe this correlates with a more rapid and durable suppression of pERK signaling (which controls growth and cell survival) when compared to other ON-only KRAS G12D inhibitors in tumor cell lines. The selective inhibition of KRAS G12D by VS-7375 has been shown, in preclinical models, to spare T cell proliferation to maintain a normal healthy immune response, versus a RAS-multi-inhibitor, which impairs T cell proliferation at increasing concentrations of drug. The once-daily oral dosing of VS-7375 achieves exposures corresponding to maximal tumor regressions across preclinical models for pancreatic, lung and colorectal cancers. Verastem announced in April 2025 that the U.S. Investigational New Drug application for (VS-7375-101) was cleared and initiated a Phase 1/2 clinical trial in June 2025 in patients with advanced KRAS G12D-mutated solid tumors, including PDAC, NSCLC and CRC.

We were incorporated under the laws of the State of Delaware in August 2010. Our principal executive offices are located at 117 Kendrick Street, Suite 500, Needham, MA 02494, and our telephone number is (781) 292-4200. Our website address is www.verastem.com. We have included our website address as a factual reference and do not intend it to be an active link to our website. The information that can be accessed through our website is not part of this prospectus, and investors should not rely on any such information in deciding whether to purchase our securities.

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RISK FACTORS

Investing in our securities involves a high degree of risk. See “Item 1A — Risk Factors” in our most recent Annual Report on Form 10-K incorporated by reference in this prospectus and in any subsequent Quarterly Report on Form 10-Q and the “Risk Factors” section in the applicable prospectus supplement for a discussion of the factors you should carefully consider before deciding to purchase our securities. Before making a decision about investing in our securities, you should carefully consider these risks as well as other information we include or incorporate by reference into this prospectus and the applicable prospectus supplement. The risks and uncertainties we have described are not the only ones facing our Company. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also affect our business operations, operating results and financial condition. The occurrence of any of these risks might cause you to lose all or part of your investment in the offered securities. The discussion of risks includes or refers to forward-looking statements; you should read the explanation of the qualifications and limitations on such forward-looking statements discussed elsewhere in this prospectus.

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FORWARD-LOOKING STATEMENTS

This prospectus, any prospectus supplement and the other documents we have filed with the SEC that are incorporated herein by reference contain forward-looking statements.

These forward-looking statements generally can be identified by the use of words such as “anticipate,” “expect,” “plan,” “could,” “may,” “believe,” “estimate,” “forecast,” “goal,” “potentially,” “project,” and other words of similar meaning. All statements, other than statements related to present facts or current conditions or historical facts, contained in or incorporated by reference into this prospectus are forward-looking statements, including statements regarding our strategy, future operations, future financial position, future revenues, projected costs, prospects, plans and objectives of management. Such statements relate to, among other things, the commercial success of our marketed product AVMAPKI® FAKZYNJA® CO-PACK (avutometinib capsules; defactinib tablets), the development and activity of our programs and product candidates, avutometinib (rapidly accelerated fibrosarcoma (“RAF”)/ mitogen-activated protein kinase kinase (“MEK”) program), defactinib (focal adhesion kinase (“FAK”) program), and VS-7375 (a selective oral KRAS G12D dual ON/OFF inhibitor), the structure and potential clinical value of our completed, planned and pending clinical trials, including the RAMP 201, RAMP 201J, RAMP 205, RAMP 301, TARGET-D 101, TARGET-D 201, TARGET-D 202, TARGET-D 203 and TARGET-D 301 trials; the timing of commencing and completing trials, including topline data reports; our interactions with regulators; the timeline and indications for clinical development, regulatory submissions and the potential for and timing of commercialization of our product candidates; the potential for additional development programs involving our lead compound and the potential market opportunities thereof; the expected outcome and benefits of our collaboration with GenFleet Therapeutics (Shanghai), Inc. (“GenFleet”) and the estimated addressable markets for, and anticipated market opportunities of, our drug candidates.

Each forward-looking statement is subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied in such statement. Applicable risks and uncertainties include the risks and uncertainties, among other things, regarding: the success in the development and potential commercialization of our product candidates; the uncertainties inherent in research and development, such as negative or unexpected results of clinical trials; the occurrence or timing of applications for our product candidates that may be filed with regulatory authorities in any jurisdictions; whether and when regulatory authorities in any jurisdictions may approve applications that may be filed for our product candidates and, if approved, whether our product candidates will be commercially successful in such jurisdictions; the impact of current and future healthcare reforms, including those affecting the delivery of or payment for healthcare products and services; our ability to obtain, maintain and enforce patent and other intellectual property protection for our product candidates; the scope, timing, and outcome of any legal proceedings; decisions by regulatory authorities regarding trial design, labeling and other matters that could affect the timing, availability or commercial potential of our product candidates; whether preclinical testing of our product candidates and preliminary or interim data from clinical trials will be representative of more mature data or predictive of the results or success of ongoing or later clinical trials; that the timing, scope and rate of reimbursement for our product candidates are uncertain; actions or advice of regulatory agencies to maintain regulatory approval of AVMAPKI FAKZYNJA CO-PACK; that the market opportunities of AVMAPKI FAKZYNJA CO-PACK are based on internal and third-party estimates which may prove to be incorrect; that third-party payors (including government agencies) may not reimburse; the Company’s pro forma cash position; uncertainties related to the regulatory and policy actions proposed and enacted by the current U.S. presidential administration that may adversely affect our business; that there may be competitive developments affecting our product candidates; that data may not be available when expected; that enrollment of clinical trials may take longer than expected; that our marketed products and product candidates may cause adverse safety events and/or unexpected concerns may arise from additional data or analysis, or result in unmanageable safety profiles as compared to their levels of efficacy; that we may be unable to successfully validate, develop and obtain regulatory approval for companion diagnostic tests for our product candidates that require or would commercially benefit from such tests, or experience significant delays in doing so; that we may not be able to confirm the results from the RAMP 201 study or expand the approved indication for AVMAPKI FAKZYNJA CO-PACK; that our product candidates may experience manufacturing or supply interruptions or failures; that any of our third-party contract research organizations, contract manufacturing organizations, clinical sites, or contractors, among others, on whom we rely may fail to fully perform; that we face substantial competition, which may result in others developing

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or commercializing products before or more successfully than we do, which could result in reduced market share or market potential for our product candidates; that the development and commercialization of our product candidates may take longer or cost more than planned, including as a result of conducting additional studies or our decisions regarding execution of such commercialization; that we may not have sufficient cash to fund our contemplated operations, including certain of our product development programs; that we may not attract and retain high-quality personnel; that we or Pfizer, Inc. (“Pfizer”) may fail to fully perform under the license agreement covering certain Pfizer FAK inhibitors, including defactinib; that we or Chugai Pharmaceutical Co. Ltd. may fail to fully perform under the avutometinib license agreement; that we or Secura Bio, Inc. (“Secura”) may fail to fully perform under the asset purchase agreement with Secura, including in relation to milestone payments; that we may not see a return on investment on the payments we have made and may continue to make pursuant to the collaboration and option agreement with GenFleet or that GenFleet may fail to fully perform under the agreement; that we may not be able to establish new or expand on existing collaborations or partnerships, including with respect to in-licensing of our product candidates, on favorable terms, or at all; that we may be unable to obtain adequate financing in the future through product licensing, co-promotional arrangements, public or private equity, debt financing or otherwise; that we may not pursue or submit regulatory filings for our product candidates; and that our product candidates will not receive regulatory approval, become commercially successful products, or result in new treatment options being offered to patients. Other risks and uncertainties include those identified under the heading “Risk Factors” contained in our Annual Report on Form 10-K for the year ended December 31, 2025, as filed with the SEC on March 4, 2026 and our subsequent Quarterly Reports on Form 10-Q, each incorporated by reference in this prospectus, in any subsequent filings with the SEC, and in the applicable “Risk Factors” section in the applicable prospectus supplement. See “Where You Can Find More Information.”

As a result of these and other factors, we may not achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments we may make. The forward-looking statements contained in this prospectus reflect our views as of the date hereof. We do not assume and specifically disclaim any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law. Our business is subject to substantial risks and uncertainties, including those referenced above. Investors, potential investors, and others should give careful consideration to these risks and uncertainties.

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USE OF PROCEEDS

Except as otherwise provided in the applicable prospectus supplement, in connection with an offering of securities pursuant to this prospectus, we currently intend to use the net proceeds we receive from the sale of any securities offered by us under this prospectus primarily for general corporate purposes, which may include working capital, capital expenditures, research and development expenditures, clinical trial expenditures, commercial expenditures, milestone payments under in-license agreements, and possible acquisitions. Additional information on the use of net proceeds we receive from the sale of securities covered by this prospectus may be set forth in the prospectus supplement relating to the specific offering.

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PLAN OF DISTRIBUTION

If we offer any securities under this prospectus, we will amend or supplement this prospectus by means of an accompanying prospectus supplement setting forth the specific terms and conditions and other information about that offering as is required or necessary.

We may sell the securities in any of the following ways (or in any combination thereof) from time to time:

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to or through one or more underwriters;

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through dealers, who may act as agents or principals (including a block trade in which a broker or dealer so engaged will attempt to sell the shares as agent but may position and resell a portion of the block as principal to facilitate the transaction);

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through one or more agents;

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through registered direct offerings;

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as part of a collaboration with a third party;

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as part of an acquisition or merger with a third party;

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through at-the-market issuances;

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in privately negotiated transactions; or

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directly to purchasers or to a single purchaser.

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

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

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at market prices prevailing at the time of sale;

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at prices related to such prevailing market prices; or

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at negotiated prices.

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

The prospectus supplement will describe the terms of the offering of the securities, including the following, as applicable:

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the terms of the securities being offered, including the public offering price of the securities and the proceeds to us;

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the name or names of any underwriters, dealers or agents and the amounts of securities underwritten or purchased by each of them;

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any underwriting discounts and commissions or agency fees and other items constituting underwriters’ or agents’ compensation;

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any options under which underwriters may purchase additional securities from us;

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any discounts or concessions allowed or reallowed or paid to dealers; and

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any securities exchanges on which the securities may be listed.

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Only the agents or underwriters named in each prospectus supplement are agents or underwriters in connection with the securities being offered thereby.

We may authorize underwriters, dealers 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 a specified date in the future. 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 each applicable prospectus supplement. Institutions with whom the contracts, when authorized,

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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 be subject only to those conditions set forth in each applicable prospectus supplement, and each prospectus supplement will set forth any commissions we pay for solicitation of these contracts.

We may indemnify agents, underwriters, dealers, their affiliates, or other third parties who participate in the distribution of securities against certain liabilities, including liabilities under the Securities Act, and agree to contribute to payments which these agents, underwriters, dealers, or other third parties may be required to make. Agents, underwriters, dealers and such other third parties may be customers of, engage in transactions with, or perform services for us in the ordinary course of business. We may also use underwriters or such other third parties with whom we have a material relationship. We will describe the nature of any such relationship in the applicable prospectus supplement.

One or more firms, referred to as “remarketing firms,” may also offer or sell the securities, if a prospectus supplement so indicates, in connection with a remarketing arrangement upon their purchase. Remarketing firms will act as principals for their own accounts or as our agents. These remarketing firms will offer or sell the securities in accordance with the terms of the securities. Each prospectus supplement will identify and describe any remarketing firm and the terms of its agreement, if any, with us and will describe the remarketing firm’s compensation. Remarketing firms may be deemed to be underwriters in connection with the securities they remarket. Remarketing firms may be entitled under agreements that may be entered into with us to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, and may engage in transactions with or perform services for us in the ordinary course of business.

Certain underwriters may use this prospectus and any accompanying prospectus supplement for offers and sales related to market-making transactions in the securities. These underwriters may act as principal or agent in these transactions, and the sales will be made at prices related to prevailing market prices at the time of sale. Any underwriters involved in the sale of the securities may qualify as “underwriters” within the meaning of Section 2(a)(11) of the Securities Act. In addition, the underwriters’ commissions, discounts or concessions may qualify as underwriters’ compensation under the Securities Act and the rules of the Financial Industry Regulatory Authority.

Our common stock is listed on The Nasdaq Capital Market. Underwriters may make a market in our common stock, but will not be obligated to do so and may discontinue any market making at any time without notice. We can give no assurance as to the development, maintenance or liquidity of any trading market for the securities.

Certain persons participating in an offering may engage in overallotment, stabilizing transactions, short covering transactions and penalty bids in accordance with rules and regulations under the Exchange Act. Overallotment involves sales in excess of the offering size, which create a short position. Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum. Short covering transactions involve purchases of the securities in the open market after the distribution is completed to cover short positions. Penalty bids permit the underwriters to reclaim a selling concession from a dealer when the securities originally sold by the dealer are purchased in a short covering transaction to cover short positions. Those activities may cause the price of the securities to be higher than it would otherwise be. If commenced, the underwriters may discontinue any of the activities at any time.

We are subject to the applicable provisions of the Exchange Act and the rules and regulations under the Exchange Act, including Regulation M, which may limit the timing of purchases and sales of any of the securities offered in this prospectus by any other person. The anti-manipulation rules under the Exchange Act may apply to sales of securities in the market and to our actions.

To the extent required, this prospectus may be amended and/or supplemented from time to time to describe a specific plan of distribution.

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DESCRIPTION OF COMMON STOCK

The description of our common stock is incorporated by reference to Exhibit 4.2 of our Annual Report on Form 10-K for the year ended December 31, 2025, as filed with the SEC on March 4, 2026, including any amendments or reports filed for the purpose of updating such description.

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DESCRIPTION OF PREFERRED STOCK

Under the terms of our amended and restated certificate of incorporation, our board of directors is authorized to issue up to 5,000,000 shares of our preferred stock, par value $0.0001 per share, in one or more series without stockholder approval. Our board of directors has the discretion to determine the rights, preferences, privileges and restrictions, including voting rights, dividend rights, conversion rights, redemption privileges and liquidation preferences, of each series of preferred stock. It is not possible to state the actual effect of the issuance of any shares of preferred stock upon the rights of the holders of common stock until the board of directors determines the specific rights of the holders of preferred stock. However, effects of the issuance of preferred stock include restricting dividends on common stock, diluting the voting power of common stock, impairing the liquidation rights of common stock, and making it more difficult for a third party to acquire us, which could have the effect of discouraging a third party from acquiring, or deterring a third party from paying a premium to acquire, a majority of our outstanding voting stock.

If we offer any additional specific class or series of preferred stock under this prospectus, we will describe the terms of the preferred stock in the prospectus supplement for such offering and will file a copy of the certificate establishing the terms of the preferred stock with the SEC. To the extent required, this description will include:

•

the title and stated value;

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•

the number of shares offered, the liquidation preference per share and the purchase price;

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•

the dividend rate(s), period(s) and/or payment date(s), or method(s) of calculation for such dividends;

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whether dividends will be cumulative or non-cumulative and, if cumulative, the date from which dividends will accumulate;

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the procedures for any auction and remarketing, if any;

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the provisions for a sinking fund, if any;

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the provisions for redemption, if applicable;

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any listing of the preferred stock on any securities exchange or market;

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whether the preferred stock will be convertible into our common stock, and, if applicable, the conversion price (or how it will be calculated) and conversion period;

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whether the preferred stock will be exchangeable into debt securities, and, if applicable, the exchange price (or how it will be calculated) and exchange period;

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•

voting rights, if any, of the preferred stock;

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•

a discussion of any material U.S. federal income tax considerations applicable to the preferred stock;

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the relative ranking and preferences of the preferred stock as to dividend rights and rights upon liquidation, dissolution or winding up of the affairs of the Company; and

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•

any material limitations on issuance of any class or series of preferred stock ranking senior to or on a parity with the series of preferred stock as to dividend rights and rights upon liquidation, dissolution or winding up of the Company.

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The preferred stock offered by this prospectus, when issued, will not have, or be subject to, any preemptive or similar rights.

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DESCRIPTION OF WARRANTS

We may issue warrants to purchase shares of our common stock, preferred stock and/or debt securities in one or more series together with other securities or separately, as described in each applicable prospectus supplement. Below is a description of certain general terms and provisions of the warrants that we may offer. Particular terms of the warrants will be described in the applicable warrant agreements and the applicable prospectus supplement for the warrants.

The applicable prospectus supplement will contain, where applicable, the following terms of and other information relating to the warrants:

•

the specific designation and aggregate number of, and the price at which we will issue, the warrants;

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•

the currency or currency units in which the offering price, if any, and the exercise price are payable;

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•

the designation, amount and terms of the securities purchasable upon exercise of the warrants;

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if applicable, the exercise price for shares of our common stock and the number of shares of common stock to be received upon exercise of the warrants;

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if applicable, the exercise price for shares of our preferred stock, the number of shares of preferred stock to be received upon exercise, and a description of that class or series of our preferred stock;

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if applicable, the exercise price for our debt securities, the amount of our debt securities to be received upon exercise, and a description of that series of debt securities;

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•

the date on which the right to exercise the warrants will begin and the date on which that right will expire or, if the warrants may not be continuously exercised throughout that period, the specific date or dates on which the warrants may be exercised;

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•

whether the warrants will be issued in fully registered form or bearer form, in definitive or global form or in any combination of these forms, although, in any case, the form of a warrant included in a unit will correspond to the form of the unit and of any security included in that unit;

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•

any applicable material U.S. federal income tax consequences;

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the identity of the warrant agent for the warrants and of any other depositaries, execution or paying agents, transfer agents, registrars or other agents;

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the proposed listing, if any, of the warrants or any securities purchasable upon exercise of the warrants on any securities exchange;

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if applicable, the date from and after which the warrants and the common stock, preferred stock and/or debt securities will be separately transferable;

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if applicable, the minimum or maximum amount of the warrants that may be exercised at any one time;

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information with respect to book-entry procedures, if any;

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the anti-dilution provisions of the warrants, if any;

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any redemption or call provisions;

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whether the warrants are to be sold separately or with other securities as parts of units; and

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any additional terms of the warrants, including terms, procedures and limitations relating to the exchange and exercise of the warrants.

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DESCRIPTION OF DEBT SECURITIES

We will issue any debt securities offered by this prospectus and any accompanying prospectus supplement under an indenture to be entered into between us and the trustee identified in the applicable prospectus supplement. The terms of the debt securities will include those stated in the indenture and those made part of the indenture by reference to the Trust Indenture Act of 1939, as in effect on the date of the indenture. We have filed a copy of the form of indenture as an exhibit to the registration statement in which this prospectus is included. The indenture will be subject to and governed by the terms of the Trust Indenture Act of 1939.

We may offer debt securities as described in this prospectus that, unless otherwise specified in the applicable prospectus supplement, will represent direct, unsecured obligations of the Company and will rank equally with all of our other unsecured indebtedness.

The applicable prospectus supplement will describe the terms and features of any debt securities which we may offer, in one or more series, as either senior or subordinated debt or as senior or subordinated convertible debt. The following description and any description of debt securities in the applicable prospectus supplement may not be complete and are subject to, and are qualified in their entirety by reference to, the indenture, any supplemental indentures or forms of debt securities, in each case that we will file with the SEC in connection with a public offering of debt securities.

General

We may issue the debt securities in one or more series with the same or various maturities, at par, at a premium, or at a discount. We will describe the particular terms of each series of debt securities in the applicable prospectus supplement relating to that series, which we will file with the SEC.

The prospectus supplement will set forth, to the extent required, the following terms of the debt securities in respect of which the prospectus supplement is delivered:

•

the title of the series (which shall distinguish the debt securities of that particular series from the debt securities of any other series);

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•

any limit upon the aggregate principal amount of the debt securities of the series which may be authenticated and delivered under the indenture;

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•

the price or prices (expressed as a percentage of the principal amount thereof) at which the series of debt securities will be issued;

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•

the date or dates on which principal of the securities of the series is payable;

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•

the rate or rates (which may be fixed or variable) per annum or, if applicable, the method used to determine such rate or rates (including, but not limited to, any commodity, commodity index, stock exchange index or financial index) at which the debt securities of the series shall bear interest, if any, the date or dates from which such interest, if any, shall accrue, the date or dates on which such interest, if any, shall commence and be payable and any regular record date for the interest payable on any interest payment date;

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•

the place or places where the principal, interest and premium, if any, on the debt securities of the series are payable, or the method of such payment, if by wire transfer, mail or other means;

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if applicable, the period or periods within which, the price or prices at which and the terms and conditions upon which the debt securities of the series may be redeemed, in whole or in part, at our option;

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our obligation, if any, to redeem or purchase the debt securities of the series pursuant to any sinking fund or analogous provisions or at the option of a holder thereof, and the period or periods within which, the price or prices at which and the terms and conditions upon which debt securities of the series shall be redeemed or purchased, in whole or in part, pursuant to such obligation;

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the dates, if any, on which and the price or prices at which the debt securities of the series will be repurchased by us at the option of the holders thereof, and other detailed terms and provisions of such repurchase obligations;

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•

if other than denominations of $1,000 and any integral multiple thereof, the denominations in which the debt securities of the series shall be issuable;

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•

the forms of the debt securities of the series in bearer (if to be issued outside of the United States of America) or fully registered form (and, if in fully registered form, whether the debt securities will be issuable as global securities);

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

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the currency of denomination of the debt securities of the series, which may be dollars or any foreign currency, and the agency or organization, if any, responsible for overseeing such composite currency;

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the designation of the currency, currencies or currency units in which payment of the principal of, and interest and premium, if any, on the debt securities of the series will be made;

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if payments of principal of, or interest or premium, if any, on the debt securities of the series are to be made in one or more currencies or currency units other than that or those in which such securities are denominated, the manner in which the exchange rate with respect to such payments will be determined;

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•

the manner in which the amounts of payment of principal of, or interest and premium, if any, on the debt securities of the series will be determined if such amounts may be determined by reference to an index based on a currency or currencies or by reference to a commodity, commodity index, stock exchange index or financial index;

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•

the provisions, if any, relating to any collateral provided for the debt securities of the series;

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any addition to or change in the covenants in the indenture which applies to the debt securities of the series;

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any addition to or change in the events of default which applies to any debt securities of the series, and any change in the right of the trustee or the requisite holders of such debt securities to declare the principal amount thereof due and payable;

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•

the terms and conditions, if any, for conversion of the debt securities into or exchange of the debt securities for shares of common stock or preferred stock of the Company that apply to debt securities of the series;

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•

any depositaries, interest rate calculation agents, exchange rate calculation agents or other agents with respect to debt securities of such series;

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the terms and conditions, if any, upon which the debt securities shall be subordinated in right of payment to other indebtedness of the Company;

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if applicable, that the debt securities of the series, in whole or any specified part, shall be defeasible; and

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•

any other terms of the debt securities of the series (which terms shall not be inconsistent with the provisions of the indenture, except as permitted by the indenture, but which may modify or delete any provision of the indenture insofar as it applies to such series).

​

We may issue discount debt securities that provide for an amount less than the stated principal amount to be due and payable upon acceleration of the maturity of such debt securities in accordance with the terms of the indenture. We may also issue debt securities in bearer form, with or without coupons. If we issue discount debt securities or debt securities in bearer form, we will describe material U.S. federal income tax considerations and other material special considerations which apply to these debt securities in the applicable prospectus supplement.

We may issue debt securities denominated in or payable in a foreign currency or currencies or a foreign currency unit or units. If we do, we will describe the restrictions, elections, and general tax considerations relating to the debt securities and the foreign currency or currencies or foreign currency unit or units in the applicable prospectus supplement.

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Exchange and/or Conversion Rights

We may issue debt securities which can be exchanged for or converted into shares of our common stock or preferred stock. If we do, we will describe the terms of exchange or conversion in the applicable prospectus supplement relating to these debt securities.

Transfer and Exchange

We may issue debt securities that will be represented by either:

•

“book-entry,” which means that there will be one or more global securities registered in the name of a depositary or a nominee of a depositary; or

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•

“certificated securities,” which means that they will be represented by a certificate issued in definitive registered form.

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We will specify in the prospectus supplement applicable to a particular offering whether the debt securities offered will be book-entry or certificated securities.

Certificated Debt Securities

If we issue certificated debt securities, a holder may transfer or exchange such debt securities at the trustee’s office or at the paying agent’s office or agency in accordance with the terms of the indenture. A holder will not be charged a service charge for any transfer or exchange of certificated debt securities but may be required to pay an amount sufficient to cover any tax or other governmental charge payable in connection with such transfer or exchange.

A holder may effect the transfer of certificated debt securities and of the right to receive the principal of, premium, and/or interest, if any, on the certificated debt securities only by surrendering the certificate representing the certificated debt securities and having us or the trustee issue a new certificate to the new holder.

Global Securities

If we decide to issue debt securities in the form of one or more global securities, then we will register the global securities in the name of the depositary for the global securities or the nominee of the depositary, and the global securities will be delivered by the trustee to the depositary for credit to the accounts of the holders of beneficial interests in the debt securities.

The prospectus supplement will describe the specific terms of the depositary arrangement for debt securities of a series that are issued in global form. None of our Company, the trustee, any payment agent or the security registrar will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in a global debt security or for maintaining, supervising or reviewing any records relating to these beneficial ownership interests.

No Protection in the Event of Change of Control

Unless we indicate otherwise in a prospectus supplement with respect to a particular series of debt securities, the debt securities will not contain any provisions that may afford holders of debt securities protection in the event we have a change in control or in the event of a highly leveraged transaction (whether or not such transaction results in a change in control).

Covenants

We will set forth in the applicable prospectus supplement any restrictive covenants applicable to any issue of debt securities.

Consolidation, Merger and Sale of Assets

Unless we indicate otherwise in a prospectus supplement, we will not, in any transaction or series of transactions, merge or consolidate with or into, or sell, assign, convey or transfer, lease or otherwise dispose of all or substantially all of our properties and assets, unless:

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•

either (A) if the transaction or series of transactions is a merger or consolidation, the Company shall be the surviving person of such merger or consolidation, or (B) the person formed by such consolidation or into which the Company is merged or to which the properties and assets of the Company are transferred shall be a corporation or entity treated as a corporation for U.S. federal income tax purposes organized and existing under the laws of the United States of America, any state thereof or the District of Columbia, or a corporation or comparable legal entity treated as a corporation for U.S. federal income tax purposes organized under the laws of a foreign jurisdiction and shall expressly assume by a supplemental indenture executed and delivered to the trustee, in form reasonably satisfactory to the trustee, all of the obligations of the Company (including, without limitation, the obligation to pay the principal of, and premium and interest, if any, on, the securities and the performance of the other covenants) under the indenture as supplemented, and in each case, the indenture shall remain in full force and effect; and

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•

immediately before and immediately after giving effect to such transaction or series of transactions on a pro forma basis (including, without limitation, any indebtedness incurred or anticipated to be incurred in connection with or in respect of such transaction or series of transactions), no default or event of default shall have occurred and be continuing.

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Events of Default

Unless otherwise specified in the applicable prospectus supplement, the following events will be events of default under the indenture with respect to debt securities of any series:

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we default in the payment of any principal of, or premium, if any, on, the debt securities when it becomes due and payable at maturity, upon acceleration, redemption or otherwise;

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we default in the payment of any interest on any debt security of a series when the same becomes due and payable, and the default continues for a period of 30 days;

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we default in observance or performance of any other covenant in the debt securities of a series or the indenture for 60 days after written notice from the trustee or the holders of not less than 25% in the aggregate principal amount of the debt securities of such series then outstanding, which notice must specify the default, demand that it be remedied and state that the notice is a “Notice of Default”;

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certain events involving bankruptcy, insolvency or reorganization of Verastem or any of our significant subsidiaries; and

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any other event of default provided for in such series of debt securities as may be specified in the applicable prospectus supplement.

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Holders of a majority in principal amount of the debt securities of any series then outstanding have the right to waive any existing default or event of default with respect to such series or compliance with any provision of the indenture (with respect to such series) or the debt securities of such series with written notice to the trustee. Upon any such waiver, such default with respect to such series shall cease to exist, and any event of default with respect to such series arising therefrom shall be deemed to have been cured for every purpose of the indenture; but no such waiver shall extend to any subsequent or other default or event of default or impair any right consequent thereto. If an event of default (other than an event of default resulting from certain events of bankruptcy, insolvency or reorganization with respect to the Company) occurs and is continuing, then the trustee, by written notice, or the holders of not less than 25% in aggregate principal amount of the outstanding debt securities of that series may declare that the entire principal amount, plus the premium, if any, of all the debt securities of that series then outstanding plus accrued and unpaid interest to the date of acceleration is immediately due and payable. At any time after the acceleration, but before a judgment or decree based on such acceleration is obtained by the trustee, the holders of a majority in aggregate principal amount of outstanding debt securities of such series may rescind and annul such acceleration if:

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all existing events of default (other than nonpayment of accelerated principal, premium or interest) have been cured or waived;

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all lawful interest on overdue installments of interest and overdue principal has been paid; and

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•

the rescission would not conflict with any judgment or decree.

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In addition, if the acceleration occurs at any time when we have outstanding indebtedness which is senior to the debt securities, the payment of the principal amount of outstanding debt securities may be subordinated in right of payment to the prior payment of any amounts due under the senior indebtedness, in which case the holders of debt securities will be entitled to payment under the terms prescribed in the instruments evidencing the senior indebtedness and the indenture.

If an event of default resulting from certain events of bankruptcy, insolvency or reorganization with respect to the Company occurs, such principal, premium, if any, and interest amount with respect to all the debt securities of that series shall be due and payable immediately without any declaration or other act on the part of the trustee or the holders of the debt securities of that series.

The holders of a majority in principal amount of the outstanding debt securities of a series will have the right to waive any existing default or compliance with any provision of the indenture or the debt securities of that series and to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, subject to certain limitations specified in the indenture.

No holder of any debt security of a series will have any right to institute any proceeding with respect to the indenture or for any remedy under the indenture, unless:

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the holder gives to the trustee written notice of a continuing event of default with respect to the debt securities of that series;

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the holders of at least 25% in aggregate principal amount of the outstanding debt securities of the affected series make a written request to the trustee;

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the holder or holders offer to the trustee indemnity satisfactory to the trustee against any loss, liability or expense to be incurred in compliance with such request;

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the trustee does not comply with the request within 60 days after such request; and

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the holders of a majority in aggregate principal amount of the outstanding debt securities of the affected series do not give the trustee a direction inconsistent with such request during such 60-day period.

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Modification and Waiver

From time to time, we and the trustee may, without the consent of holders of the debt securities of one or more series, amend the indenture or the debt securities of one or more series, or supplement the indenture, for certain specified purposes, including:

•

to provide that the surviving entity following a change of control of Verastem permitted under the indenture will assume all of our obligations under the indenture and debt securities;

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to provide for certificated debt securities in addition to uncertificated debt securities;

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to comply with any requirements of the SEC under the Trust Indenture Act of 1939;

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to cure any mistake, ambiguity, defect or inconsistency, or make any other change that does not materially and adversely affect the rights of any holder;

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to provide for the issuance of and establish the form and terms and conditions of debt securities of any series as permitted by the indenture; and

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to evidence and provide for the acceptance of the appointment of a successor trustee under the indenture with respect to one or more series and to add to or change any of the provisions of the indenture as shall be necessary to provide for or facilitate the administration of the trusts by more than one trustee.

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From time to time we and the trustee may, with the consent of holders of not less than a majority of the aggregate principal amount of an outstanding series of debt securities, amend or supplement the indenture or the debt securities of such series, or waive compliance in a particular instance by us with any

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provision of the indenture or the debt securities. We may not, however, without the consent of each holder affected by such action, modify or supplement the indenture or the debt securities or waive compliance with any provision of the indenture or the debt securities in order to:

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reduce the amount of debt securities whose holders must consent to an amendment, supplement, or waiver to the indenture or such debt security;

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reduce the rate of or change the time for payment of interest on any of the debt securities;

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reduce the principal of or change the stated maturity of the debt securities, or reduce the amount of, or postpone the date fixed for, the payment of any sinking fund or analogous obligation;

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make any debt security payable in money other than that stated in the debt security;

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change the amount or time of any payment required by the debt securities or reduce the premium payable upon any redemption of the debt securities, or change the time before which no such redemption may be made;

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waive a default or event of default in the payment of the principal of, or interest or premium, if any, on any debt securities (except a rescission of acceleration of the debt securities of any series by the holders of at least a majority in principal amount of the outstanding debt securities of such series and a waiver of the payment default that resulted from such acceleration);

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waive a redemption payment with respect to any debt securities or change any provision with respect to redemption of debt securities;

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take any other action otherwise prohibited by the indenture to be taken without the consent of each holder affected by the action; or

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make any changes to the above provisions or the acceleration provisions of the indenture, except to increase any percentage of debt securities the holders of which must consent to any matter.

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Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

The indenture permits us, at any time, to elect to discharge our obligations with respect to one or more series of debt securities by following certain procedures described in the indenture. These procedures will allow us either:

•

to defease and be discharged from any and all of our obligations with respect to any debt securities except for the following obligations (which discharge is referred to as “legal defeasance”):

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(1)

to replace temporary or mutilated, destroyed, lost or stolen debt securities;

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(2)

the rights, powers, trusts, duties and immunities of the trustee; and

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(3)

to maintain an office or agency in respect of the debt securities and to hold monies for payment in trust; or

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to be released from our obligations with respect to the debt securities under certain covenants contained in the indenture, as well as any additional covenants which may be contained in an applicable supplemental indenture (which release is referred to as “covenant defeasance”).

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In order to exercise either defeasance option, we must irrevocably deposit with the trustee or other qualifying trustee, in trust for that purpose:

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money;

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U.S. Government Obligations (as described below) or Foreign Government Obligations (as described below) which through the scheduled payment of principal and interest in accordance with their terms will provide, not later than the due date of any payment, money; or

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a combination of money and/or U.S. Government Obligations and/or Foreign Government Obligations sufficient in the written opinion of a nationally recognized firm of independent accountants to provide money;

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which, in each case specified above, provides an amount sufficient to pay the principal of, premium, if any, and interest, if any, on the debt securities of the series, on the scheduled due dates or on a selected date of redemption in accordance with the terms of the indenture.

In addition, defeasance may be effected only if, among other things:

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in the case of either legal or covenant defeasance, we deliver to the trustee an opinion of counsel, as specified in the indenture;

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in the case of legal defeasance, we deliver to the trustee an opinion of counsel stating that we have received from, or there has been published by, the Internal Revenue Service a ruling to the effect that, or there has been a change in any applicable federal income tax law with the effect that, and such opinion shall confirm that, the holders of the outstanding debt securities of such series or persons will not recognize income, gain or loss for U.S. federal income tax purposes solely as a result of such legal defeasance and will be subject to U.S. federal income tax on the same amounts, in the same manner, including as a result of prepayment, and at the same times as would have been the case if legal defeasance had not occurred;

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in the case of covenant defeasance, we deliver to the trustee an opinion of counsel to the effect that the holders of the outstanding debt securities will not recognize income, gain or loss for U.S. federal income tax purposes as a result of covenant defeasance and will be subject to U.S. federal income tax on the same amounts, in the same manner and at the same times as would have been the case if covenant defeasance had not occurred; and

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certain other conditions described in the indenture are satisfied.

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If we fail to comply with our remaining obligations under the indenture and any applicable supplemental indenture after a covenant defeasance of the indenture and any applicable supplemental indenture, and the debt securities are declared due and payable because of the occurrence of any undefeased event of default, the amount of money and/or U.S. Government Obligations and/or Foreign Government Obligations on deposit with the trustee could be insufficient to pay amounts due under the debt securities of the affected series at the time of acceleration. We will, however, remain liable in respect of these payments.

The term “U.S. Government Obligations” as used in the above discussion means direct non-callable obligations of or non-callable obligations guaranteed by the United States of America for the payment of which obligation or guarantee the full faith and credit of the United States of America is pledged.

The term “Foreign Government Obligations” as used in the above discussion means, with respect to securities that are denominated in a foreign currency, (i) direct obligations of the government that issued or caused to be issued such currency for the payment of which obligations its full faith and credit is pledged or (ii) obligations of a person controlled or supervised by or acting as an agency or instrumentality of such government the timely payment of which is unconditionally guaranteed as a full faith and credit obligation by such government, which, in either case under clauses (i) and (ii), are not callable or redeemable at the option of the issuer thereof.

Regarding the Trustee

We will identify the trustee with respect to any series of debt securities in the prospectus supplement relating to the applicable debt securities. You should note that if the trustee becomes a creditor of Verastem, the indenture and the Trust Indenture Act of 1939 limit the rights of the trustee to obtain payment of claims in certain cases, or to realize on certain property received in respect of any such claim, as security or otherwise. The trustee and its affiliates may engage in, and will be permitted to continue to engage in, other transactions with us and our affiliates. If, however, the trustee acquires any “conflicting interest” within the meaning of the Trust Indenture Act of 1939, it must eliminate such conflict or resign.

The holders of a majority in principal amount of the then outstanding debt securities of any series may direct the time, method and place of conducting any proceeding for exercising any remedy available to the trustee. If an event of default occurs and is continuing, the trustee, in the exercise of its rights and powers, must use the degree of care and skill of a prudent person under the same circumstances in the conduct of his or her own affairs. Subject to that provision, the trustee will be under no obligation to exercise any of its

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rights or powers under the indenture at the request of any of the holders of the debt securities, unless they have offered to the trustee indemnity or security against the costs, expenses and liabilities which may be incurred therein or thereby.

Governing Law

The indenture and the debt securities, including any claim or controversy arising out of or relating to the indenture or the securities, will be governed by the laws of the State of New York.

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WHERE YOU CAN FIND MORE INFORMATION

This prospectus is part of a registration statement we filed with the SEC. This prospectus does not contain all of the information set forth in the registration statement and the exhibits to the registration statement. For further information, we refer you to the registration statement and the exhibits and schedules filed as a part of the registration statement.

We file annual, quarterly and current reports, proxy statements and other information with the SEC. The SEC maintains a website that contains reports, proxy statements and other information regarding issuers that file electronically with the SEC, including us. The address of the SEC website is www.sec.gov.

We maintain a website at www.verastem.com. Information contained in, or accessible through, our website is not a part of, and is not incorporated into, this prospectus, and you should not consider it part of this prospectus.

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INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

The SEC allows us to “incorporate by reference” into this prospectus certain information we file with it, which means that we can disclose important information about us by referring you to those documents. The information incorporated by reference is considered to be a part of this prospectus, and information in documents that we file later with the SEC will automatically update and supersede information in this prospectus. We incorporate by reference into this prospectus the documents listed below and any future filings, including all filings made after the date of the filing and effectiveness of the registration statement of which this prospectus is part, made by us with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, except for information “furnished” under Items 2.02, 7.01 or 9.01 on Form 8-K or other information “furnished” to the SEC which is not deemed filed and not incorporated in this prospectus, until the termination of the offering of securities described in the applicable prospectus supplement. We hereby incorporate by reference the following documents:

•

our Annual Report on Form 10-K for the year ended December 31, 2025, as filed with the SEC on March 4, 2026;

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•

our Quarterly Reports on Form 10-Q for the quarter ended March 31, 2026, as filed with the SEC on May 7, 2026, for the quarter ended June 30, 2026, as filed with the SEC on August 6, 2026, and for the quarter ended September 30, 2026, as filed with the SEC on November 5, 2026;

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•

our Current Reports on Form 8-K filed with the SEC on February 4, 2026, May 26, 2026, June 17, 2026, June 23, 2026, August 6, 2026, August 7, 2026, October 14, 2026 and October 14, 2026;

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•

the information specifically incorporated by reference into our Annual Report on Form 10-K for the year ended December 31, 2025, from our Definitive Proxy Statement on Schedule 14A for the 2026 Annual Meeting of Stockholders, as filed with the SEC on April 9, 2026; and

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•

the description of our common stock, which is in our Registration Statement on Form 8-A, dated January 23, 2012, as supplemented by the description of our common stock and preferred stock contained in Exhibit 4.2 to our Annual Report on Form 10-K for the fiscal year ended December 31, 2025, filed with the SEC on March 4, 2026.

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Any statement contained in a document incorporated or deemed to be incorporated by reference in this prospectus will be deemed modified, superseded or replaced for purposes of this prospectus to the extent that a statement contained in this prospectus modifies, supersedes or replaces such statement.

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

Investor Relations
Verastem, Inc.
117 Kendrick Street, Suite 500
Needham, Massachusetts 02494
(781) 292-4279
email address: investors@verastem.com

Copies of these filings are also available, without charge, on the SEC’s website at www.sec.gov and on our website at www.verastem.com as soon as reasonably practicable after they are filed electronically with the SEC. The information contained on our website is not a part of this prospectus.

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LEGAL MATTERS

The validity of the issuance of the securities offered pursuant to this prospectus will be passed upon for us by Ropes & Gray LLP, Boston, Massachusetts. The validity of any securities will be passed upon for any underwriters or agents by counsel that we will name in the applicable prospectus supplement.

EXPERTS

The consolidated financial statements of Verastem, Inc. appearing in Verastem, Inc.’s Annual Report on Form 10-K for the year ended December 31, 2025, have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their report thereon, included therein, and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such report given on the authority of such firm as experts in accounting and auditing.

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PROSPECTUS SUPPLEMENT

Up to $100,000,000
Common Stock

​

We previously entered into a Sales Agreement (the “Sales Agreement”) with Cantor Fitzgerald & Co. (“Cantor”), as sales agent, relating to the sale of shares of our common stock, $0.0001 par value per share, offered by this prospectus supplement. We originally filed a prospectus supplement, dated August 8, 2025, as amended on August 12, 2025, with an accompanying prospectus (the “Prior Prospectus”), for the offer and sale of shares of our common stock having an aggregate offering price of up to $100.0 million from time to time through Cantor, acting as our sales agent, pursuant to the Sales Agreement under the shelf registration statement on Form S-3 (No. 333-289399). We did not issue or sell any shares of common stock under the Sales Agreement pursuant to the Prior Prospectus, which Prior Prospectus we suspended and terminated on October 14, 2026. Any shares of common stock to be sold pursuant to the Sales Agreement will be offered and sold under this prospectus supplement. In accordance with the terms of the Sales Agreement, under this prospectus supplement we may offer and sell shares of our common stock from time to time having an aggregate offering price of up to $100.0 million through Cantor, acting as our sales agent.

Our common stock is listed on The Nasdaq Capital Market under the symbol “VSTM.” On November 4, 2026, the last reported sale price of our common stock was $9.85 per share.

Sales of our common stock, if any, under this prospectus supplement may be made in sales deemed to be “at-the-market” equity offerings as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, or the Securities Act. Cantor will act as sales agent on a best efforts basis and use commercially reasonable efforts to sell on our behalf all of the shares of common stock requested to be sold by us, consistent with its normal trading and sales practices, on mutually agreed terms between Cantor and us. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.

Cantor will be entitled to compensation at a commission rate of up to 3.0% of the gross sales price per share sold. In connection with the sale of our common stock on our behalf, Cantor will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of Cantor will be deemed to be underwriting commissions or discounts.

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Investing in our common stock involves a high degree of risk. Before making an investment decision, please read the information under the heading “Risk Factors” beginning on page S-5 of this prospectus supplement and in the documents incorporated by reference into this prospectus supplement.

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

The date of this prospectus supplement is November 5, 2026

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TABLE OF CONTENTS

​	​	​	Page				​
ABOUT THIS PROSPECTUS SUPPLEMENT	​	​	​	​	S-1	​	​
PROSPECTUS SUPPLEMENT SUMMARY	​	​	​	​	S-2	​	​
THE OFFERING	​	​	​	​	S-3	​	​
RISK FACTORS	​	​	​	​	S-5	​	​
FORWARD-LOOKING STATEMENTS	​	​	​	​	S-6	​	​
USE OF PROCEEDS	​	​	​	​	S-8	​	​
PLAN OF DISTRIBUTION	​	​	​	​	S-9	​	​
DESCRIPTION OF COMMON STOCK	​	​	​	​	S-10	​	​
LEGAL MATTERS	​	​	​	​	S-11	​	​
EXPERTS	​	​	​	​	S-11	​	​
WHERE YOU CAN FIND MORE INFORMATION	​	​	​	​	S-11	​	​
INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE	​	​	​	​	S-11	​	​

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ABOUT THIS PROSPECTUS SUPPLEMENT

This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of this offering. The second part, the accompanying prospectus, gives more general information, some of which may not apply to this offering. In the event that the description of this offering varies between this prospectus supplement and the accompanying prospectus, you should rely on the information contained in this prospectus supplement. This prospectus supplement includes or incorporates by reference important information about us, our common stock, and other matters you should know before investing. You should read this prospectus supplement as well as additional information described under the sections of this prospectus supplement entitled “Where You Can Find More Information” and “Incorporation of Certain Documents by Reference” before making an investment decision.

You should rely only on this prospectus supplement and the information incorporated or deemed to be incorporated by reference in this prospectus supplement or in any free writing prospectus that we may authorize for use in connection with this offering. We have not, and Cantor has not, authorized anyone to provide you with information that is in addition to, or different from, that contained or incorporated by reference in this prospectus supplement. If anyone provides you with different or inconsistent information, you should not rely on it. We are not, and Cantor is not, making an offer to sell or soliciting an offer to buy our securities in any jurisdiction in which an offer or solicitation is not authorized or in which the person making that offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make an offer or solicitation. You should not assume that the information contained or incorporated by reference in this prospectus supplement is accurate as of any date other than as of the date of this prospectus supplement or in the case of the documents incorporated by reference, the date of such documents regardless of the time of delivery of this prospectus supplement or any sale of shares of our common stock. Our business, financial condition, liquidity, results of operations and prospects may have changed since those dates.

We are offering to sell, and seeking offers to buy, shares of common stock only in jurisdictions where offers and sales are permitted. The distribution of this prospectus supplement and the offering of the common stock in certain jurisdictions may be restricted by law. Persons outside the United States who come into possession of this prospectus supplement must inform themselves about, and observe any restrictions relating to, the offering of the common stock and the distribution of this prospectus supplement outside the United States. This prospectus supplement does not constitute, and may not be used in connection with, an offer to sell, or a solicitation of an offer to buy, any securities offered by this prospectus supplement by any person in any jurisdiction in which it is unlawful for such person to make such an offer or solicitation.

References in this prospectus supplement to “Verastem,” the “Company,” “we,” “us,” “our” or similar terms refer to Verastem, Inc. and our subsidiaries on a consolidated basis, as appropriate, unless we state otherwise or the context otherwise requires.

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PROSPECTUS SUPPLEMENT SUMMARY

This summary highlights selected information included or incorporated by reference in this prospectus supplement and does not contain all of the information that may be important to you. You should review this entire prospectus supplement and any free writing prospectus supplement we have authorized for use in connection with this offering carefully, including the risk factors and financial statements included or incorporated by reference herein or therein.

Company Overview

We are a biopharmaceutical company committed to the development and commercialization of new medicines to improve the lives of patients diagnosed with rat sarcoma (“RAS”)/ mitogen-activated protein kinase (“MAPK”) pathway-driven cancers. On May 8, 2025, the U.S. Food and Drug Administration approved AVMAPKI FAKZYNJA CO-PACK (avutometinib capsules; defactinib tablets) for the treatment of adult patients with Kirsten rat sarcoma viral oncogene homolog (“KRAS”) mutant recurrent low-grade serous ovarian cancer who received prior systemic therapy. We market AVMAPKI FAKZYNJA CO-PACK in the United States. Our pipeline is focused on novel small molecule drugs that inhibit critical signaling pathways in cancer that promote cancer cell survival and tumor growth, including RAF/MEK inhibition, FAK inhibition and KRAS G12D inhibition.

AVMAPKI (avutometinib) inhibits MEK kinase activity while also blocking the compensatory reactivation of MEK by upstream RAF. RAF and MEK proteins are regulators of the RAS/RAF/MEK/​ERK (MAPK) pathway. Blocking RAF and/or MEK activates FAK, a key mediator of drug resistance. FAKZYNJA (defactinib) is a FAK inhibitor, and together, the avutometinib and defactinib combination was designed to provide a more complete blockade of the signaling that drives the growth and drug resistance of RAS/MAPK pathway-dependent tumors.

For our clinical-stage pipeline programs, we are evaluating VS-7375, a potential best-in-class oral KRAS G12D (ON/OFF) inhibitor, for the treatment of patients with KRAS G12D-mutated cancers, including pancreatic ductal adenocarcinoma (“PDAC”), non-small cell lung cancer (“NSCLC”), colorectal cancer (“CRC”) and other KRAS G12D-mutated cancers. Based on preclinical data, VS-7375 offers dual, potent inhibition of both ON and OFF states of KRAS G12D. We believe this correlates with better in vivo efficacy and durability versus ON-only RAS inhibitors. VS-7375 has demonstrated a high affinity for KRAS G12D with a long residence time (18-24 hours) in preclinical models. We believe this correlates with a more rapid and durable suppression of pERK signaling (which controls growth and cell survival) when compared to other ON-only KRAS G12D inhibitors in tumor cell lines. The selective inhibition of KRAS G12D by VS-7375 has been shown, in preclinical models, to spare T cell proliferation to maintain a normal healthy immune response, versus a RAS-multi-inhibitor, which impairs T cell proliferation at increasing concentrations of drug. The once-daily oral dosing of VS-7375 achieves exposures corresponding to maximal tumor regressions across preclinical models for pancreatic, lung and colorectal cancers. Verastem announced in April 2025 that the U.S. Investigational New Drug application for (VS-7375-101) was cleared and initiated a Phase 1/2 clinical trial in June 2025 in patients with advanced KRAS G12D-mutated solid tumors, including PDAC, NSCLC and CRC.

We were incorporated under the laws of the State of Delaware in August 2010. Our principal executive offices are located at 117 Kendrick Street, Suite 500, Needham, MA 02494, and our telephone number is (781) 292-4200. Our website address is www.verastem.com. We have included our website address as a factual reference and do not intend it to be an active link to our website. The information that can be accessed through our website is not part of this prospectus supplement, and investors should not rely on any such information in deciding whether to purchase our securities.

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THE OFFERING

Common stock offered by us

Shares of our common stock having an aggregate offering price of up to $100,000,000.

Manner of offering

“At-the-market” offering that may be made from time to time through our sales agent, Cantor. See “Plan of Distribution” on page S-9.

Common Stock to be Outstanding After this Offering

Up to 104,620,983 shares of our common stock, assuming the sale of 10,152,284 shares of our common stock in this offering at an assumed offering price of $9.85 per share, which was the last reported sale price of our common stock on Nasdaq on November 4, 2026. The actual number of shares of our common stock issued will vary depending on the sales prices under this offering.

Use of proceeds

If we receive all $100,000,000 of gross proceeds from the sale of the shares of our common stock under this prospectus supplement, we anticipate that our net proceeds, after deducting estimated commissions and expenses payable by us, will be approximately $97.6 million. We intend to use the net proceeds from this offering to fund commercial activities for the AVMAPKI FAKZYNJA CO-PACK, continued clinical development of VS-7375, continued clinical research and development of other product candidates, and for working capital and other general corporate purposes, which may include capital expenditures, research and development expenditures, clinical trial expenditures, potential commercial launch expenditures, milestone payments under collaboration and in-license agreements, and possible acquisitions. See “Use of Proceeds” on page S-8.

Risk factors

You should read the “Risk Factors” section of this prospectus supplement and the documents incorporated by reference in this prospectus supplement for a discussion of factors to consider before deciding to purchase shares of our common stock.

The Nasdaq Capital Market symbol

VSTM

The number of shares of common stock shown above to be outstanding after this offering is based on 94,468,699 shares outstanding as of September 30, 2026, and excludes:

•

3,248,991 shares of our common stock issuable upon the exercise of stock options outstanding under our Amended and Restated 2012 Incentive Plan, our Amended and Restated 2021 Equity Incentive Plan, and our inducement award program (collectively, our “Equity Incentive Plans”), at a weighted-average exercise price of $8.65 per share;

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•

3,823,547 shares of our common stock issuable upon the settlement of restricted stock units under our Equity Incentive Plans including 269,247 restricted stock units that were vested but unsettled as of September 30, 2026;

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•

10,970,607 shares of our common stock reserved and available for future issuance under our Amended and Restated 2021 Equity Incentive Plan, of which 70,625 shares are issuable upon the vesting of restricted stock units granted subsequent to September 30, 2026, under the Amended and Restated 2021 Equity Incentive Plan;

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941,829 shares of our common stock reserved and available for future issuance under our inducement award program, of which 380,500 shares are issuable upon the vesting of restricted stock units and

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50,000 shares are issuable upon the exercise of stock options at a weighted-average exercise price of $7.90 per share granted subsequent to September 30, 2026, under the inducement award program;

•

5,017,782 shares of our common stock reserved for future issuance under our Amended and Restated 2018 Employee Stock Purchase Plan;

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•

30,937,500 shares of our common stock issued and sold pursuant to the underwriting agreement dated October 14, 2026 (the “Underwriting Agreement”), among Verastem, Inc., Jefferies LLC and Guggenheim Securities, LLC, as representatives of the underwriters named therein;

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•

312,503 shares of our common stock issued upon exercise of pre-funded warrants issued and sold pursuant to the Underwriting Agreement; and

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•

9,727,142 shares of our common stock issuable upon the exercise of our currently outstanding pre-funded warrants at an exercise price equal to $0.0001 per share.

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Unless otherwise indicated, all information in this prospectus supplement reflects or assumes no issuance or exercise of stock options or warrants after September 30, 2026.

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RISK FACTORS

You should consider carefully the risks described below and discussed under the section captioned “Risk Factors” contained in our annual report on Form 10-K for the year ended December 31, 2025 and in any subsequent quarterly reports on Form 10-Q and annual reports on Form 10-K, as updated by our subsequent filings under the Exchange Act, each of which is incorporated by reference in this prospectus supplement, together with other information in this prospectus supplement, and the information and documents incorporated by reference in this prospectus supplement, and any free writing prospectus that we have authorized for use in connection with this offering before you make a decision to invest in our common stock. If any of the following events actually occur, our business, operating results, prospects or financial condition could be materially and adversely affected. This could cause the trading price of our common stock to decline and you may lose all or part of your investment. The risks described below are not the only ones that we face. Additional risks not presently known to us or that we currently deem immaterial may also affect our business operations.

Additional Risks Relating to this Offering and Our Common Stock

We may allocate the net proceeds from this offering in ways that you and other stockholders may not approve.

We currently intend to use the net proceeds of this offering, if any, to fund commercial activities for the AVMAPKI FAKZYNJA CO-PACK, continued clinical development of VS-7375, continued clinical research and development of other product candidates, and for working capital and other general corporate purposes, which may include capital expenditures, research and development expenditures, clinical trial expenditures, potential commercial launch expenditures, milestone payments under collaboration and in-license agreements, and possible acquisitions. This expected use of the net proceeds from this offering represents our intentions based upon our current plans and business conditions. The amounts and timing of our actual expenditures may vary significantly depending on numerous factors, including the progress of our development efforts, the status of and results from clinical trials, as well as any collaborations that we may enter into with third parties for our product candidates, and any unforeseen cash needs. Because of the number and variability of factors that will determine our use of the proceeds from this offering, their ultimate use may vary substantially from their currently intended use. As a result, our management will retain broad discretion over the allocation of the net proceeds from this offering and could spend the proceeds in ways that do not necessarily improve our operating results or enhance the value of our common stock. See “Use of Proceeds.”

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FORWARD-LOOKING STATEMENTS

This prospectus, any prospectus supplement and the other documents we have filed with the SEC that are incorporated herein by reference contain forward-looking statements.

These forward-looking statements generally can be identified by the use of words such as “anticipate,” “expect,” “plan,” “could,” “may,” “believe,” “estimate,” “forecast,” “goal,” “potentially,” “project,” and other words of similar meaning. All statements, other than statements related to present facts or current conditions or historical facts, contained in or incorporated by reference into this prospectus are forward-looking statements, including statements regarding our strategy, future operations, future financial position, future revenues, projected costs, prospects, plans and objectives of management. Such statements relate to, among other things, the commercial success of our marketed product AVMAPKI® FAKZYNJA® CO-PACK (avutometinib capsules; defactinib tablets), the development and activity of our programs and product candidates, avutometinib (rapidly accelerated fibrosarcoma (“RAF”)/ mitogen-activated protein kinase kinase (“MEK”) program), defactinib (focal adhesion kinase (“FAK”) program), and VS-7375 (a selective oral KRAS G12D dual ON/OFF inhibitor), the structure and potential clinical value of our completed, planned and pending clinical trials, including the RAMP 201, RAMP 201J, RAMP 205, RAMP 301, TARGET-D 101, TARGET-D 201, TARGET-D 202, TARGET-D 203 and TARGET-D 301 trials; the timing of commencing and completing trials, including topline data reports; our interactions with regulators; the timeline and indications for clinical development, regulatory submissions and the potential for and timing of commercialization of our product candidates; the potential for additional development programs involving our lead compound and the potential market opportunities thereof; the expected outcome and benefits of our collaboration with GenFleet Therapeutics (Shanghai), Inc. (“GenFleet”) and the estimated addressable markets for, and anticipated market opportunities of, our drug candidates.

Each forward-looking statement is subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied in such statement. Applicable risks and uncertainties include the risks and uncertainties, among other things, regarding: the success in the development and potential commercialization of our product candidates; the uncertainties inherent in research and development, such as negative or unexpected results of clinical trials; the occurrence or timing of applications for our product candidates that may be filed with regulatory authorities in any jurisdictions; whether and when regulatory authorities in any jurisdictions may approve applications that may be filed for our product candidates and, if approved, whether our product candidates will be commercially successful in such jurisdictions; the impact of current and future healthcare reforms, including those affecting the delivery of or payment for healthcare products and services; our ability to obtain, maintain and enforce patent and other intellectual property protection for our product candidates; the scope, timing, and outcome of any legal proceedings; decisions by regulatory authorities regarding trial design, labeling and other matters that could affect the timing, availability or commercial potential of our product candidates; whether preclinical testing of our product candidates and preliminary or interim data from clinical trials will be representative of more mature data or predictive of the results or success of ongoing or later clinical trials; that the timing, scope and rate of reimbursement for our product candidates are uncertain; actions or advice of regulatory agencies to maintain regulatory approval of AVMAPKI FAKZYNJA CO-PACK; that the market opportunities of AVMAPKI FAKZYNJA CO-PACK are based on internal and third-party estimates which may prove to be incorrect; that third-party payors (including government agencies) may not reimburse; the Company’s pro forma cash position; uncertainties related to the regulatory and policy actions proposed and enacted by the current U.S. presidential administration that may adversely affect our business; that there may be competitive developments affecting our product candidates; that data may not be available when expected; that enrollment of clinical trials may take longer than expected; that our marketed products and product candidates may cause adverse safety events and/or unexpected concerns may arise from additional data or analysis, or result in unmanageable safety profiles as compared to their levels of efficacy; that we may be unable to successfully validate, develop and obtain regulatory approval for companion diagnostic tests for our product candidates that require or would commercially benefit from such tests, or experience significant delays in doing so; that we may not be able to confirm the results from the RAMP 201 study or expand the approved indication for AVMAPKI FAKZYNJA CO-PACK; that our product candidates may experience manufacturing or supply interruptions or failures; that any of our third-party contract research organizations, contract manufacturing organizations, clinical sites, or contractors, among others, on whom we rely may fail to fully perform; that we face substantial competition, which may result in others developing

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or commercializing products before or more successfully than we do, which could result in reduced market share or market potential for our product candidates; that the development and commercialization of our product candidates may take longer or cost more than planned, including as a result of conducting additional studies or our decisions regarding execution of such commercialization; that we may not have sufficient cash to fund our contemplated operations, including certain of our product development programs; that we may not attract and retain high-quality personnel; that we or Pfizer Inc. (“Pfizer”) may fail to fully perform under the license agreement covering certain Pfizer FAK inhibitors, including defactinib; that we or Chugai Pharmaceutical Co., Ltd. may fail to fully perform under the avutometinib license agreement; that we or Secura Bio, Inc. (“Secura”) may fail to fully perform under the asset purchase agreement with Secura, including in relation to milestone payments; that we may not see a return on investment on the payments we have made and may continue to make pursuant to the collaboration and option agreement with GenFleet or that GenFleet may fail to fully perform under the agreement; that we may not be able to establish new or expand on existing collaborations or partnerships, including with respect to in-licensing of our product candidates, on favorable terms, or at all; that we may be unable to obtain adequate financing in the future through product licensing, co-promotional arrangements, public or private equity, debt financing or otherwise; that we may not pursue or submit regulatory filings for our product candidates; and that our product candidates will not receive regulatory approval, become commercially successful products, or result in new treatment options being offered to patients. Other risks and uncertainties include those identified under the heading “Risk Factors” contained in our Annual Report on Form 10-K for the year ended December 31, 2025, as filed with the SEC on March 4, 2026 and our subsequent Quarterly Reports on Form 10-Q, each incorporated by reference in this prospectus supplement, in any subsequent filings with the SEC, and in the “Risk Factors” section of this prospectus supplement. See “Where You Can Find More Information.”

As a result of these and other factors, we may not achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments we may make. The forward-looking statements contained in this prospectus supplement reflect our views as of the date hereof. We do not assume and specifically disclaim any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law. Our business is subject to substantial risks and uncertainties, including those referenced above. Investors, potential investors, and others should give careful consideration to these risks and uncertainties.

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USE OF PROCEEDS

If we receive all $100,000,000 of gross proceeds from the sale of the shares of our common stock under this prospectus supplement, we anticipate that the net proceeds we will receive from this offering will be approximately $97.6 million, after deducting the estimated underwriting discounts and commissions and estimated offering expenses payable by us. The amount of the proceeds from this offering will depend upon the number of shares of our common stock sold and the market price at which they are sold. There can be no assurance that we will be able to sell any shares under or fully utilize the Sales Agreement with Cantor as a source of financing.

We intend to use the net proceeds from this offering to fund commercial activities for the AVMAPKI FAKZYNJA CO-PACK, continued clinical development of VS-7375, continued clinical research and development of other product candidates, and for working capital and other general corporate purposes, which may include capital expenditures, research and development expenditures, clinical trial expenditures, potential commercial launch expenditures, milestone payments under collaboration and in-license agreements, and possible acquisitions.

This expected use of the net proceeds from this offering represents our intentions based upon our current plans and business conditions. The amounts and timing of our actual expenditures may vary significantly depending on numerous factors, including the progress of our development efforts, the status of and results from clinical trials, as well as any collaborations that we may enter into with third parties for our product candidates, and any unforeseen cash needs. As a result, we cannot estimate with certainty the amount of net proceeds to be used for the purposes described above, and our management will retain broad discretion over the allocation of the net proceeds from this offering.

Pending our use of the net proceeds from this offering described above, we intend to invest the net proceeds in a variety of capital preservation investments, including short-term, investment-grade, interest-bearing instruments and U.S. government securities.

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PLAN OF DISTRIBUTION

We have entered into a Sales Agreement with Cantor, under which we may issue and sell shares of our common stock having an aggregate gross sales price of up to $100,000,000 from time to time through Cantor acting as sales agent. The Sales Agreement has been incorporated by reference as an exhibit to our registration statement on Form S-3 of which this prospectus supplement forms a part.

Upon delivery of a placement notice and subject to the terms and conditions of the Sales Agreement, Cantor may sell shares of our common stock by any method permitted by law deemed to be an “at-the-market” offering as defined in Rule 415 promulgated under the Securities Act. We may instruct Cantor not to sell common stock if the sales cannot be effected at or above the price designated by us from time to time. We or Cantor may suspend the offering of common stock upon notice and subject to other conditions.

We will pay Cantor commissions, in cash, for its services in acting as agent in the sale of our common stock. Cantor will be entitled to compensation at a commission rate of up to 3.0% of the gross sales price per share sold. Because there is no minimum offering amount required as a condition to close this offering, the actual total public offering amount, commissions and proceeds to us, if any, are not determinable at this time. We also agreed to reimburse Cantor for the reasonable out-of-pocket fees and disbursements of its legal counsel, which were payable upon execution of the Sales Agreement, in an amount not to exceed $75,000, in addition to ongoing disbursements of legal counsel payable in an amount not to exceed $25,000 in connection with each diligence bring-down or program refresh thereafter.

Settlement for sales of shares of common stock will occur on the first business day following the date on which any sales are made, or on some other date that is agreed upon by us and Cantor in connection with a particular transaction, in return for payment of the net proceeds to us. Sales of our common stock as contemplated in this prospectus supplement will be settled through the facilities of The Depository Trust Company or by such other means as we and Cantor may agree upon. There is no arrangement for funds to be received in an escrow, trust or similar arrangement.

Cantor will use its commercially reasonable efforts, consistent with its sales and trading practices, to solicit offers to purchase the shares of common stock under the terms and subject to the conditions set forth in the Sales Agreement. In connection with the sale of the shares of common stock on our behalf, Cantor will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of Cantor will be deemed to be underwriting commissions or discounts. We have agreed to provide indemnification and contribution to Cantor against certain civil liabilities, including liabilities under the Securities Act.

The offering of shares of our common stock pursuant to the Sales Agreement will terminate upon the earlier of (i) the sale of all the shares of our common stock that are subject to the Sales Agreement having an aggregate offering price of $100,000,000 or (ii) termination of the Sales Agreement as permitted therein. We and Cantor may each terminate the Sales Agreement at any time upon ten days’ prior notice.

Cantor and its affiliates may in the future provide various investment banking, commercial banking and other financial services for us and our affiliates, for which services they may in the future receive customary fees. To the extent required by Regulation M, Cantor will not engage in any market making activities involving our common stock while the offering is ongoing under this prospectus supplement.

This prospectus supplement in electronic format may be made available on a website maintained by Cantor, and Cantor may distribute this prospectus supplement electronically.

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DESCRIPTION OF COMMON STOCK

The description of our common stock is incorporated by reference to Exhibit 4.2 of our most recent Annual Report on Form 10-K, including any amendments or reports filed for the purpose of updating such description.

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LEGAL MATTERS

The validity of the issuance of the securities offered hereby will be passed upon by our counsel, Ropes & Gray LLP, Boston, Massachusetts. Cantor is being represented in connection with this offering by Latham & Watkins LLP, San Diego, California.

EXPERTS

The consolidated financial statements of Verastem, Inc. appearing in Verastem, Inc.’s Annual Report on Form 10-K for the year ended December 31, 2025, have been audited by Ernst & Young LLP, an independent registered public accounting firm, as set forth in their report thereon, included therein, and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such report given on the authority of such firm as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

This prospectus supplement is part of a registration statement we filed with the SEC. This prospectus supplement does not contain all of the information set forth in the registration statement and the exhibits to the registration statement. For further information, we refer you to the registration statement and the exhibits and schedules filed as a part of the registration statement.

We file annual, quarterly and current reports, proxy statements and other information with the SEC. The SEC maintains a website that contains reports, proxy statements and other information regarding issuers that file electronically with the SEC, including us. The address of the SEC website is www.sec.gov.

We maintain a website at www.verastem.com. Information contained in, or accessible through, our website is not a part of, and is not incorporated into, this prospectus supplement, and you should not consider it part of this prospectus supplement.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

The SEC allows us to “incorporate by reference” the information we file with it, which means that we can disclose important information about us by referring you to those documents instead of having to repeat the information in this prospectus supplement. The information incorporated by reference is considered to be part of this prospectus supplement, and later information that we file with the SEC will automatically update and supersede this information. We incorporate by reference into this prospectus supplement the documents listed below and any future filings, including all filings made after the date of the filing and effectiveness of the registration statement of which this prospectus supplement is part, made by us with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, except for information “furnished” under Items 2.02, 7.01 or 9.01 on Form 8-K or other information “furnished” to the SEC which is not deemed filed and not incorporated in this prospectus supplement, until the termination of the offering of securities described in this prospectus supplement. We hereby incorporate by reference the following documents:

•

our Annual Report on Form 10-K for the year ended December 31, 2025, as filed with the SEC on March 4, 2026;

​

•

our Quarterly Reports on Form 10-Q for the quarter ended March 31, 2026, as filed with the SEC on May 7, 2026, for the quarter ended June 30, 2026, as filed with the SEC on August 6, 2026, and for the quarter ended September 30, 2026, as filed with the SEC on November 5, 2026;

​

•

our Current Reports on Form 8-K filed with the SEC on February 4, 2026, May 26, 2026, June 17, 2026, June 23, 2026, August 6, 2026, August 7, 2026, October 14, 2026 and October 14, 2026;

​

•

the information specifically incorporated by reference into our Annual Report on Form 10-K for the year ended December 31, 2025, from our Definitive Proxy Statement on Schedule 14A for the 2026 Annual Meeting of Stockholders, as filed with the SEC on April 9, 2026; and

​

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•

the description of our common stock, which is in our Registration Statement on Form 8-A, dated January 23, 2012, as supplemented by the description of our common stock and preferred stock contained in Exhibit 4.2 to our Annual Report on Form 10-K for the fiscal year ended December 31, 2025, filed with the SEC on March 4, 2026.

​

Any statement contained in a document incorporated or deemed to be incorporated by reference in this prospectus supplement will be deemed modified, superseded or replaced for purposes of this prospectus supplement to the extent that a statement contained in this prospectus supplement modifies, supersedes or replaces such statement.

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

Investor Relations
Verastem, Inc.
117 Kendrick Street, Suite 500
Needham, Massachusetts 02494
(781) 292-4279
email address: investors@verastem.com

Copies of these filings are also available, without charge, on the SEC’s website at www.sec.gov and on our website at www.verastem.com as soon as reasonably practicable after they are filed electronically with the SEC. The information contained on our website is not a part of this prospectus supplement.

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​

​

Up to $100,000,000
Common Stock

​

PROSPECTUS SUPPLEMENT

​

November 5, 2026

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PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14.   Other Expenses of Issuance and Distribution.

The following table sets forth the various expenses to be incurred in connection with the issuance and distribution of the offered securities being registered, other than underwriting discounts and commissions.

​	Securities and Exchange Commission registration fee	​	​	​	$	(1)(2)	​	​
​	Printing and engraving expenses	​	​	​	​	​ *	​	​
​	Legal fees and expenses	​	​	​	​	​ *	​	​
​	Accounting fees and expenses	​	​	​	​	​ *	​	​
​	Transfer Agent and Registrar fees	​	​	​	​	​ *	​	​
​	Trustee’s fees and expenses	​	​	​	​	​ *	​	​
​	Miscellaneous	​	​	​	​	​ *	​	​
​	Total	​	​	​	$	​ *	​	​

​

(1)

In accordance with Rules 456(b) and 457(r) of the Securities Act, we are deferring payment of the registration fee for the securities offered under this registration statement other than the $100,000,000 of our common stock that may be issued and sold from time to time under the sales agreement prospectus supplement.

​

(2)

The registrant is filing this registration statement to replace its existing registration statement (File No. 333-289399) (the “Prior Registration Statement”). A portion of the filing fee associated with this registration statement was carried forward from the Prior Registration Statement, and an additional filing fee is due only in connection with the $49,999,992.75 maximum aggregate offering price of new securities registered upon the effectiveness of this registration statement. Pursuant to Rule 415(a)(6) under the Securities Act, the offering of unsold securities with a maximum aggregate offering price of $50,000,007.25 under the Prior Registration Statement will be deemed terminated as of the date of effectiveness of this registration statement. Please see the registration fee table contained in Exhibit 107 to this registration statement for more information.

​

*

Estimated expenses are not presently known and will be reflected in the applicable prospectus supplement.

​

Item 15.   Indemnification of Directors and Officers.

Section 102 of the Delaware General Corporation Law permits a corporation to eliminate the personal liability of its directors to the corporation or its stockholders for monetary damages for a breach of fiduciary duty as a director, except where the director breached his or her duty of loyalty, failed to act in good faith, engaged in intentional misconduct or knowingly violated a law, authorized the payment of a dividend or approved a stock repurchase in violation of Delaware corporate law or obtained an improper personal benefit. Our amended and restated certificate of incorporation provides that no director shall be personally liable to us or our stockholders for monetary damages for any breach of fiduciary duty as a director, notwithstanding any provision of law imposing such liability, except to the extent that the Delaware General Corporation Law prohibits the elimination or limitation of liability of directors for breaches of fiduciary duty.

Section 145 of the Delaware General Corporation Law provides that a corporation has the power to indemnify a director, officer, employee or agent of the corporation and certain other persons serving at the request of the corporation in related capacities against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by the person in connection with an action, suit or proceeding to which he or she is a party or is threatened to be made a party by reason of such position, if such person acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the corporation, and, in any criminal action or proceeding, had no

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reasonable cause to believe his or her conduct was unlawful, except that, in the case of actions brought by or in the right of the corporation, no indemnification shall be made with respect to any claim, issue or matter as to which such person shall have been adjudged to be liable to the corporation unless and only to the extent that the Court of Chancery or other adjudicating court determines that, despite the adjudication of liability but in view of all of the circumstances of the case, such person is fairly and reasonably entitled to indemnification for such expenses which the Court of Chancery or such other court shall deem proper.

Our amended and restated certificate of incorporation provides that we will indemnify each person who was or is a party or threatened to be made a party to any threatened, pending or completed action, suit or proceeding whether civil, criminal, administrative or investigative (other than an action by or in the right of us) by reason of the fact that he or she is or was, or has agreed to become, our director or officer, or is or was serving, or has agreed to serve, at our request as a director, officer, partner, employee or trustee of, or in a similar capacity with, another corporation, partnership, joint venture, trust or other enterprise (all such persons being referred to as an “Indemnitee”), or by reason of any action alleged to have been taken or omitted in such capacity, against all expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred in connection with such action, suit or proceeding and any appeal therefrom, if such Indemnitee acted in good faith and in a manner he or she reasonably believed to be in, or not opposed to, our best interests, and, with respect to any criminal action or proceeding, he or she had no reasonable cause to believe his or her conduct was unlawful.

Our amended and restated certificate of incorporation also provides that we will indemnify any Indemnitee who was or is a party to an action or suit by or in the right of us to procure a judgment in our favor by reason of the fact that the Indemnitee is or was, or has agreed to become, our director or officer, or is or was serving, or has agreed to serve, at our request as a director, officer, partner, employee or trustee of, or in a similar capacity with, another corporation, partnership, joint venture, trust or other enterprise, or by reason of any action alleged to have been taken or omitted in such capacity, against all expenses (including attorneys’ fees) and, to the extent permitted by law, amounts paid in settlement actually and reasonably incurred in connection with such action, suit or proceeding, and any appeal therefrom, if the Indemnitee acted in good faith and in a manner he or she reasonably believed to be in, or not opposed to, our best interests, except that no indemnification shall be made with respect to any claim, issue or matter as to which such person shall have been adjudged to be liable to us, unless a court determines that, despite such adjudication but in view of all of the circumstances, he or she is entitled to indemnification of such expenses. Notwithstanding the foregoing, to the extent that any Indemnitee has been successful, on the merits or otherwise, he or she will be indemnified by us against all expenses (including attorneys’ fees) actually and reasonably incurred by him or her or on his or her behalf in connection therewith. If we do not assume the defense, expenses must be advanced to an Indemnitee under certain circumstances.

We have entered into indemnification agreements with our directors. In general, these agreements provide that we will indemnify the director to the fullest extent permitted by law for claims arising in his or her capacity as a director of our Company or in connection with his or her service at our request for another corporation or entity. The indemnification agreements also provide for procedures that will apply in the event that a director makes a claim for indemnification and establish certain presumptions that are favorable to the director.

We maintain a general liability insurance policy which covers certain liabilities of our directors and officers arising out of claims based on acts or omissions in their capacities as directors or officers.

Also see “Undertakings.”

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Item 16.   Exhibits.

​	Exhibit	​	​	Description	​
​	1.1	​	​	Form of Underwriting Agreement*	​
​	1.2	​	​	Sales Agreement, dated August 8, 2025, by and between the Company and Cantor Fitzgerald & Co. (incorporated by reference to Exhibit 1.2 to the Registration Statement on Form S-3 as filed with the SEC on August 8, 2025)	​
​	3.1	​	​	Restated Certificate of Incorporation of the Registrant (incorporated by reference to Exhibit 3.1 of the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 as filed with the SEC on March 12, 2019)	​
​	3.2	​	​	Certificate of Amendment to the Restated Certificate of Incorporation of the Registrant (incorporated by reference to Exhibit 3.2 to the Annual Report on Form 10-K filed by the Registrant on March 12, 2019)	​
​	3.3	​	​	Certificate of Amendment to the Restated Certificate of Incorporation of Verastem, Inc. (incorporated by reference to Exhibit 3.1 to the Form 8-K filed by the Registrant with the SEC on May 21, 2020)	​
​	3.4	​	​	Certificate of Amendment to Restated Certificate of Incorporation of Verastem, Inc. (incorporated by reference to Exhibit 3.1 to the Form 8-K filed by the Registrant with the SEC on May 31, 2023)	​
​	3.5	​	​	Amended and Restated Bylaws of the Company (incorporated by reference to Exhibit 3.4 to Amendment No. 3 to the Registration Statement on Form S-1 as filed with the SEC on January 13, 2012)	​
​	3.6	​	​	Certificate of Designation of Preferences, Rights and Limitations of Series A Convertible Preferred Stock (incorporated by reference to Exhibit 3.1 to the Form 8-K filed by the Registrant with the SEC on November 7, 2022)	​
​	3.7	​	​	Certificate of Designation of Preferences, Rights and Limitations of Series B Convertible Preferred Stock (incorporated by reference to Exhibit 3.1 to the Form 8-K filed by the Registrant with the SEC on January 25, 2023)	​
​	4.1	​	​	Specimen certificate evidencing shares of common stock (incorporated by reference to Exhibit 4.1 to Amendment No. 3 to the Registration Statement on Form S-1 as filed with the SEC on January 13, 2012)	​
​	4.2	​	​	Description of Securities (incorporated by reference to Exhibit 4.2 to the Annual Report on Form 10-K filed by the Registrant on March 4, 2026)	​
​	4.3	​	​	Form of Pre-Funded Warrant to Purchase Common Stock (incorporated by reference to Exhibit 10.3 to the Form 8-K filed by the Registrant with the Securities and Exchange Commission on April 25, 2025)	​
​	4.4	​	​	Form of Pre-Funded Warrant (incorporated by reference to Exhibit 4.1 to Form 8-K filed by the Registrant with the Securities and Exchange Commission on November 17, 2025)	​
​	4.5	​	​	Form of Common Stock Warrant Agreement and Warrant Certificate*	​
​	4.6	​	​	Form of Preferred Stock Warrant Agreement and Warrant Certificate*	​
​	4.7	​	​	Form of Debt Securities Warrant Agreement and Warrant Certificate*	​
​	4.8	​	​	Form of Indenture (filed herewith)	​
​	5.1	​	​	Opinion of Ropes & Gray LLP relating to the base prospectus (filed herewith)	​
​	5.2	​	​	Opinion of Ropes & Gray LLP relating to the at-the-market offering prospectus supplement (filed herewith)	​
​	23.1	​	​	Consent of Ropes & Gray LLP (included in Exhibit 5.1)	​
​	23.2	​	​	Consent of Ropes & Gray LLP (included in Exhibit 5.2)	​
​	23.3	​	​	Consent of Ernst & Young LLP (filed herewith)	​
​	24.1	​	​	Power of Attorney (incorporated by reference to the signature page hereto)	​
​	25.1	​	​	Statement of Eligibility of Trustee Under Debt Indenture (filed herewith)	​
​	107	​	​	Filing Fee Table (filed herewith)	​

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​

*

To be filed, if necessary, subsequent to the effectiveness of this registration statement by an amendment to this registration statement or incorporated by reference pursuant to a Current Report on Form 8-K in connection with the offering of securities.

​

Item 17.   Undertakings.

(a)   The undersigned registrant hereby undertakes:

(1)   To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i)   To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

(ii)   To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Filing Fee Tables” or “Calculation of Registration Fee” table, as applicable, in the effective registration statement;

(iii)   To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided, however, that the undertakings set forth in paragraphs (1)(i), (1)(ii) and (1)(iii) above do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in this registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of this registration statement.

(2)   That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3)   To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4)   That, for the purpose of determining liability under the Securities Act of 1933 to any purchaser:

(i)   If the registrant is relying on Rule 430B:

(A)   Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(B)   Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5), or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii), or (x) for the purpose of providing the information required by Section 10(a) of the Securities Act of 1933 shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person

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that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

(ii)   If the registrant is subject to Rule 430C, each prospectus filed pursuant to Rule 424(b) as part of a registration statement relating to an offering, other than registration statements relying on Rule 430B or other than prospectuses filed in reliance on Rule 430A, shall be deemed to be part of and included in the registration statement as of the date it is first used after effectiveness. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such first use, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such date of first use.

(5)   That, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities, the undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser: (i) any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424; (ii) any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant; (iii) the portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and (iv) any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

(6)   That, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant’s annual report pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(7)   That, for purposes of determining any liability under the Securities Act of 1933:

(i)   the information omitted from the form of prospectus filed as part of the registration statement in reliance upon Rule 430A and contained in the form of prospectus filed by the Registrant pursuant to Rule 424(b)(1) or (4) or 497(h) under the Securities Act of 1933 shall be deemed to be part of the registration statement as of the time it was declared effective; and

(ii)   each post-effective amendment that contains a form of prospectus shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(8)   To file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act of 1939 in accordance with the rules and regulations prescribed by the Commission under Section 305(b)(2) of the Trust Indenture Act of 1939.

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Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions or otherwise, the registrant has been advised that in the opinion of the Commission such indemnification is against public policy as expressed in the Securities Act and is therefore unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act of 1933, and will be governed by the final adjudication of such issue.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement on Form S-3 to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Needham, Commonwealth of Massachusetts on November 5, 2026.

VERASTEM, INC.

By:

/s/ Daniel W. Paterson

​

​

Daniel W. Paterson
President and Chief Executive Officer

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Daniel W. Paterson and Daniel Calkins and each of them, either of whom may act without the joinder of the other, as his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and in his or her name, place, and stead, in any and all capacities, to sign any and all amendments and supplements thereto (including post-effective amendments and registration statements filed pursuant to Rule 462(b)) to this registration statement, and to file the same, with all exhibits thereto, and other documents in connection therewith with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or either of them, or their or his or her substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed below by the following persons in the capacities and on the dates indicated.

​	SIGNATURES	​	​	TITLE	​	​	DATE	​
​	/s/ Daniel W. Paterson ​ Daniel W. Paterson	​	​	President, Chief Executive Officer and Director (Principal executive officer)	​	​	November 5, 2026	​
​	/s/ Daniel Calkins ​ Daniel Calkins	​	​	Chief Financial Officer (Principal financial and accounting officer)	​	​	November 5, 2026	​
​	/s/ Brian M. Stuglik ​ Brian M. Stuglik	​	​	Director	​	​	November 5, 2026	​
​	/s/ Paul A. Bunn, M.D. ​ Paul A. Bunn, M.D.	​	​	Director	​	​	November 5, 2026	​
​	/s/ Michael Bailey ​ Michael Bailey	​	​	Director	​	​	November 5, 2026	​
​	/s/ John H. Johnson ​ John H. Johnson	​	​	Director	​	​	November 5, 2026	​
​	/s/ Anil Kapur ​ Anil Kapur	​	​	Director	​	​	November 5, 2026	​

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​	SIGNATURES	​	​	TITLE	​	​	DATE	​
​	/s/ Michael Kauffman, M.D., Ph.D. ​ Michael Kauffman, M.D., Ph.D.	​	​	Director	​	​	November 5, 2026	​
​	/s/ Michelle Robertson ​ Michelle Robertson	​	​	Director	​	​	November 5, 2026	​
​	/s/ Eric Rowinsky, M.D. ​ Eric Rowinsky, M.D.	​	​	Director	​	​	November 5, 2026	​
​	/s/ Karin Tollefson ​ Karin Tollefson	​	​	Director	​	​	November 5, 2026	​

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