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

Rhea-AI Filing Summary

Cidara Therapeutics, Inc. (Nasdaq: CDTX) has filed a high-impact Form 424B5 prospectus supplement to offer up to $250 million of common stock and pre-funded warrants, with an additional 15% over-allotment option (≈$37.5 million) available to the underwriters J.P. Morgan, Morgan Stanley, Guggenheim Securities and Cantor. Based on the assumed reference price of $21.02 (June 20, 2025 close), the base deal would involve roughly 11.9 million new shares; final pricing will be negotiated. The company is a “smaller reporting company,” allowing scaled disclosure.

Use of proceeds & strategic context. While the final allocation is not yet disclosed, management notes that recent capital events illustrate clear deployment priorities. In April 2024, Cidara reacquired worldwide rights to its lead antiviral CD388 from Janssen by paying an $85 million upfront funded out of a $240 million private placement. Two additional private raises (November 2024: $105 million; April 2024 balance: $155 million) are already being applied to CD388 clinical advancement. The new $250 million raise (plus any over-allotment) would further bolster liquidity for planned Phase 3 trials, manufacturing scale-up and potential regulatory filing costs.

Clinical portfolio. CD388 is a long-acting, multivalent zanamivir-Fc conjugate engineered on the proprietary Cloudbreak platform to deliver season-long protection against all influenza A and B strains, including high-pathogenicity H5N1. Development history includes two Phase 1 studies, one Phase 2a and the large 5,041-subject Phase 2b NAVIGATE trial. On June 23, 2025 the company announced positive topline results: each of three single-dose regimens met the primary prevention-efficacy endpoint over 24 weeks and all secondary endpoints, in healthy adults aged 18-64.

Portfolio focus. Concurrent with the Janssen license, Cidara divested its non-Cloudbreak asset rezafungin to Napp Pharmaceutical Group, streamlining R&D to a single influenza franchise. Management characterises CD388 as a potential best-in-class neuraminidase inhibitor capable of single-dose seasonal or pandemic prophylaxis.

Offering mechanics & risk disclosure. Investors are reminded that the prospectus flags “a high degree of risk,” including clinical, regulatory, manufacturing and dilution risks. Final pricing, commission structure and net proceeds are still blank pending marketing. The underwriters expect closing on or about an unspecified date in 2025.

Insights

Biotechnology Equity Analyst

TL;DR: $250 M raise plus positive Phase 2b data materially strengthen CDTX’s cash runway and de-risk lead asset.

The proposed common-stock/warrant offering, combined with the over-allotment, could supply up to $287.5 M gross, extending funding well into Phase 3 execution for CD388. Positive NAVIGATE results validate the Cloudbreak platform and support a potentially pivotal programme. Reacquisition of global rights enables Cidara to retain full economics, increasing strategic flexibility for partnerships or eventual commercialisation. Share dilution is real (≈28-30% vs. current basic shares) but the trade-off appears favourable given the value inflection. Importantly, management already raised $345 M privately, evidencing institutional appetite. Overall signal is constructive for long-term holders.

Portfolio Risk Manager

TL;DR: Financing improves liquidity, but early-stage profile and heavy dilution temper risk-adjusted return.

Though the offering fortifies the balance sheet, CD388 remains pre-Phase 3. Historical attrition rates for antivirals and the lack of diversified pipeline heighten single-asset risk. Being a smaller reporting company means thinner disclosure and potentially higher volatility. Investors face immediate dilution and pricing is still uncertain, leaving room for market-driven repricing. I view the net effect as neutral until clearer Phase 3 timelines and cash burn guidance emerge.

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Filed Pursuant to Rule 424(b)(5)
Registration No. 333-287104

The information in this preliminary prospectus supplement is not complete and may be changed. A registration statement relating to these securities has been filed with the Securities and Exchange Commission and is effective. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securities and they are not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED JUNE 23, 2025

Preliminary Prospectus Supplement

(To prospectus dated May 15, 2025)

$250,000,000

Common Stock

Pre-Funded Warrants to Purchase Shares of Common Stock

We are offering $250,000,000 of shares of our common stock at a purchase price of $    per share.

Our common stock is traded on the Nasdaq Capital Market, or Nasdaq, under the symbol “CDTX.” On June 20, 2025, the last reported sale price of our common stock on Nasdaq was $21.02 per share. Based on an assumed public offering price of $21.02 per share, the last reported sale price of our common stock on the Nasdaq Capital Market on June 20, 2025, we would expect to offer approximately 11,893,434 shares hereby. The final public offering price will be determined through negotiation between us and the lead underwriters in the offering and the recent market price used throughout this prospectus supplement may not be indicative of the actual offering price.

We are a “smaller reporting company” as defined under the federal securities laws and, as such, have elected to comply with certain reduced public company disclosure and reporting requirements.

		Per Share				Total
Public offering price		$				$
Underwriting discounts and commissions(1)		$				$
Proceeds to Cidara Therapeutics, Inc., before expenses		$				$

(1) See “Underwriting” for a description of the compensation payable to the underwriters.

We have granted the underwriters an option to purchase up to an additional $37,500,000 of shares of our common stock from us at the public offering price, less underwriting discounts and commissions, within 30 days from the date of this prospectus supplement. If the underwriters exercise the option in full, the total underwriting discounts and commissions payable by us will be $     and the total proceeds to us, before expenses, will be $    . See “Underwriting” for more information.

Investing in our common stock involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading “Risk factors” beginning on page S-7 of 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 or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The underwriters expect to deliver the shares to purchasers on or about       , 2025.

J.P. Morgan Morgan Stanley Guggenheim Securities Cantor

     , 2025

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TABLE OF CONTENTS

Prospectus supplement

About this prospectus supplement			S-ii
Prospectus supplement summary			S-1
Risk factors			S-7
Special note regarding forward-looking statements			S-10
Use of proceeds			S-12
Dilution			S-13
Underwriting			S-15
Legal matters			S-23
Experts			S-23
Where you can find more information			S-23
Incorporation of certain information by reference			S-24

Prospectus

About this prospectus			i
Summary			1
Risk factors			6
Special note regarding forward-looking statements			7
Use of proceeds			9
Description of capital stock			10
Description of debt securities			15
Description of warrants			22
Legal ownership of securities			25
Plan of distribution			29
Legal matters			31
Experts			31
Where you can find more information			31
Incorporation of certain information by reference			32

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About this prospectus supplement

This document is in two parts. The first part is this prospectus supplement, which describes the terms of this offering of our common stock and also adds to and updates information contained in the accompanying prospectus and the documents incorporated by reference into this prospectus supplement and the accompanying prospectus. The second part, the accompanying prospectus dated May 15, 2025, including the documents incorporated by reference therein, provides more general information. Generally, when we refer to this prospectus, we are referring to both parts of this document combined. To the extent there is a conflict between the information contained in this prospectus supplement, on the one hand, and the information contained in the accompanying prospectus or in any document incorporated by reference that was filed with the SEC before the date of this prospectus supplement, on the other hand, you should rely on the information in this prospectus supplement. If any statement in one of these documents is inconsistent with a statement in another document having a later date—for example, a document incorporated by reference in the accompanying prospectus—the statement in the document having the later date modifies or supersedes the earlier statement.

We have not, and the underwriters have not, authorized anyone to provide any information other than that contained or incorporated by reference in this prospectus supplement, the accompanying prospectus or in any free writing prospectus that we have authorized for use in connection with this offering. We and the underwriters take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. The information contained in this prospectus supplement, the accompanying prospectus, any free writing prospectus that we have authorized for use in connection with this offering, including the documents incorporated by reference herein or therein, is accurate only as of the respective dates thereof, regardless of the time of delivery of this prospectus supplement and the accompanying prospectus or of any sale of our common stock. It is important for you to read and consider all information contained in this prospectus supplement, the accompanying prospectus and any free writing prospectus that we have authorized for use in connection with this offering, including the documents incorporated by reference herein and therein, in making your investment decision. You should also read and consider the information in the documents to which we have referred you in the sections titled “Where you can find more information” and “Incorporation of certain information by reference” in this prospectus supplement and in the accompanying prospectus.

We and the underwriters are offering to sell, and seeking offers to buy, share of our common stock only in jurisdictions in which offers and sales are permitted. The distribution of this prospectus supplement and the accompanying prospectus and the offering of our common stock in certain jurisdictions may be restricted by law. Persons outside the United States who come into possession of this prospectus supplement and the accompanying prospectus must inform themselves about, and observe any restrictions relating to, the offering of our common stock and the distribution of this prospectus supplement and the accompanying prospectus outside the United States. This prospectus supplement and the accompanying prospectus do 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 and the accompanying prospectus by any person in any jurisdiction in which it is unlawful for such person to make such an offer or solicitation.

Except as otherwise indicated herein or as the context otherwise requires, references in this prospectus supplement, the accompanying prospectus and the information incorporated by referenced herein or therein to “Cidara,” “the Company,” “we,” “us,” “our” and similar terms refer to Cidara Therapeutics, Inc. and its consolidated subsidiaries.  

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Prospectus supplement summary

This summary highlights certain information about us, this offering and selected information contained elsewhere in or incorporated by reference into this prospectus supplement. This summary does not contain all of the information that you should consider before investing in our common stock. Before you decide to invest in our common stock, you should carefully read the prospectus supplement and the accompanying prospectus and any related free writing prospectus, including the section titled “Risk factors” contained in this prospectus supplement, as well as the information included in any free writing prospectus that we have authorized for use in connection with this offering, and under similar headings in the other documents that are incorporated by reference herein and therein. You should also carefully read the information incorporated by reference into this prospectus supplement and the accompanying prospectus, including our consolidated financial statements and related notes, and the exhibits to the registration statement of which this prospectus supplement and the accompanying prospectus are a part, before making an investment decision.

Company overview

We are a biotechnology company using our proprietary Cloudbreak^® platform to develop drug-Fc conjugate therapeutics designed to save lives and improve the standard of care for patients facing serious diseases.

Our lead clinical-stage asset is CD388, a novel long-acting antiviral which we are developing for broad spectrum influenza prophylaxis. CD388 combines a novel multivalent presentation of zanamivir, the antiviral small molecule that is the active ingredient of a U.S. Food and Drug Administration, or FDA,-approved drug, with a human antibody fragment to prolong half-life. As a broad-spectrum antiviral that is not dependent on the host immune response for activity, it has the potential to overcome key limitations of existing vaccines. Its unique properties substantially enhance its antiviral activity, making it a potential best-in-class neuraminidase inhibitor. We believe it has the potential to provide universal protection against all influenza A and B virus strains, including high pathogenicity strains like H5N1, also known as avian influenza or bird flu, with potential for single dose per flu season protection.

We discovered and advanced CD388 to the clinic under a license and collaboration agreement, or the Janssen Collaboration Agreement, that we entered in March 2021 with J&J Innovative Medicine, previously Janssen Pharmaceuticals, Inc., one of the Janssen Pharmaceutical Companies of Johnson & Johnson, or Janssen. In 2023, as part of a prioritization of its research and development, or R&D, business, Janssen disclosed its intention to discontinue internal development of multiple product candidates in its infectious disease pipeline, including CD388. Janssen subsequently conducted a competitive divestiture process of its infectious disease portfolio in which we participated and subsequently reacquired all rights to develop and commercialize CD388 in April 2024. Under the terms of a license and technology transfer agreement we entered into with Janssen in April 2024, or the Janssen License Agreement, we received an exclusive, worldwide, fee-bearing but royalty-free license under certain Janssen-controlled technology to develop, manufacture and commercialize CD388 for prophylaxis and treatment of influenza. To date, we have completed two Phase 1 studies and one Phase 2a study of CD388 under the Janssen Collaboration Agreement, and we have completed our 5,041 subject, randomized, double-blind, controlled Phase 2b clinical trial, or the NAVIGATE study, evaluating the efficacy and safety of CD388 for pre-exposure prophylaxis of seasonal influenza.

Concurrently with the CD388 reacquisition in April 2024, we completed a private placement, which provided $240.0 million in gross proceeds, of which we used $85.0 million to fund the upfront payment under the Janssen License Agreement. The remainder of the gross proceeds of $155.0 million, together with gross proceeds of $105.0 million from a private placement we completed in November 2024, are being utilized to fund the ongoing development of CD388.

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In addition, in April 2024 we simultaneously divested rezafungin, our sole non-Cloudbreak asset, to enable us to focus our resources on the development of CD388. We entered into an asset purchase agreement with Napp Pharmaceutical Group Limited, or Napp, an affiliate of Mundipharma Medical Company, our licensee for the asset in all territories other than the United States, or U.S., and Japan, pursuant to which we sold to Napp all of our rezafungin assets, including our right to receive future milestones and royalties.

Following these transactions, our sole R&D focus has now shifted to developing CD388 as a highly potent antiviral designed to deliver universal prophylaxis and treatment of seasonal and pandemic influenza.

Recent Developments

On June 23, 2025, we announced positive topline results from our randomized, double-blind, placebo-controlled Phase 2b NAVIGATE trial evaluating CD388 for the prevention of seasonal influenza in healthy unvaccinated adults aged 18 to 64. The study met its primary endpoint, demonstrating a statistically significant prevention efficacy, or PE, for each of three dose groups in individuals who received a single dose of CD388 at the beginning of the flu season and were evaluated for laboratory and clinically confirmed influenza over 24 weeks. The study also met all secondary endpoints, including efficacy at 37.8 and 37.2 degree Celsius temperature thresholds, as well as maintenance of PE up to 28 weeks with statistical significance. Over the same period, CD388 was well-tolerated at all doses with no unexpected dose-limiting treatment-emergent adverse events observed.

Efficacy Analyses:

				150 mg N = 11753 n (%)		300 mg N = 11923 n (%)		450 mg N = 11873 n (%)		Placebo N = 11723 n (%)
		Number of Participants Protocol-Defined ILI2		14 (1.2%)		13 (1.1%)		8 (0.7%)		33 (2.8%)
Primary Endpoint1		Prevention Efficacy		57.7%		61.3%		76.1%		–
		95% CI (%)		21.1, 78.9		27.0, 81.2		49.3, 89.9		–
		p-value		0.0050		0.0024		<0.0001		–

ILI, influenza like illness; CI, confidence interval

1. Statistical significance for grouped 300mg + 450mg dose groups was met (PE = 68.6%, p<0.0001), allowing testing of individual dose groups.

2. ILI event defined as central laboratory-confirmed RT-PCR+ influenza infection (nasopharyngeal swab), new onset of fever (oral temperature ≥38.0°C), and new onset of ≥2 respiratory symptoms (nasal congestion, sore throat, cough) or ≥1 respiratory symptom and ≥1 systemic symptom (headache, feeling feverish, body aches/pains, fatigue).

3. Sample size (N) indicates evaluable population at time of primary analysis data cut (April 30, 2025). Key Secondary Endpoints:

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				150 mg N = 11753 n (%)		300 mg N = 11923 n (%)		450 mg N = 11873 n (%)		Placebo N = 11723 n (%)
		Number of Participants with ≥ 37.8 °C Temp1		15 (1.3%)		15 (1.3%)		8 (0.7%)		33 (2.8%)
Secondary Endpoints		Prevention Efficacy		54.7%		55.3%		76.1%
		95% CI (%)		16.7, 77.4		18.0, 77.8		49.3, 89.9
		p-value		0.0084		0.0073		<0.0001
		Number of Participants with ≥ 37.2 C Temp2		22 (1.9%)		21 (1.8%)		12 (1.0%)		41 (3.5%)
		Prevention Efficacy		46.5%		49.6%		71.1%
		95% CI (%)		10.2, 69.3		14.8, 71.9		45.8, 86.1
		p-value		0.0148		0.0083		<0.0001

ILI, influenza like illness; CI, confidence interval

1. CDC definition: ILI event defined as central laboratory-confirmed RT-PCR+ influenza infection (nasopharyngeal swab), new onset of fever (oral temperature ≥37.8°C), and new onset of ≥2 respiratory symptoms (nasal congestion, sore throat, cough).

2. ILI event defined as central laboratory-confirmed RT-PCR+ influenza infection (nasopharyngeal swab), new onset of fever (oral temperature ≥37.2°C), and new onset of ≥2 respiratory symptoms (nasal congestion, sore throat, cough) or ≥1 respiratory symptom and ≥1 systemic symptom (headache, feeling feverish, body aches/pains, fatigue).

3. Sample size (N) indicates evaluable population at time of primary analysis data cut (April 30, 2025).

Safety and tolerability data were similar in all arms with no safety signals observed. No drug-related serious adverse events were observed, and treatment-emergent adverse events showed no dose-dependent pattern between CD388 and placebo groups. Injection site reaction rates were similar across all CD388 dose groups and placebo.

The Company expects to present additional results from the NAVIGATE trial at upcoming scientific conferences in 2025.

We have submitted an end of Phase 2 meeting request to the FDA to review the Phase 2b results and further discuss the Phase 3 trial design and start time.

Additional financing

We are actively pursuing additional sources of financing, which may include debt, royalty financing, proceeds from partnering, government funding or other sources. While we believe such additional financing will be available to us, there can be no assurance that we will be able to conduct a debt, royalty or other financing transaction on terms and conditions acceptable to us, or at all. Accordingly, you should not assume that we will successfully consummate any such additional financing transaction.

Corporate information

We were incorporated in Delaware as K2 Therapeutics, Inc. in December 2012. In July 2014, we changed our name to Cidara Therapeutics, Inc. Our principal executive offices are located at 6310 Nancy Ridge Drive, Suite 101, San Diego, California 92121, and our telephone number is (858) 752-6170.

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We formed wholly-owned subsidiaries, Cidara Therapeutics UK Limited, in England, and Cidara Therapeutics (Ireland) Limited, in Ireland, in March 2016 and October 2018, respectively, for the purpose of developing our product candidates in Europe. Our internet website address is www.cidara.com. We do not incorporate the information on or accessible through our website into this prospectus. The information contained on, or that can be accessed through, our website is not a part of, and is not incorporated by reference info, this prospectus supplement and should not be considered a part of this prospectus supplement. We have included our website address in this prospectus supplement solely as an inactive textual reference.

All brand names or trademarks appearing in this prospectus supplement are the property of their respective holders. Use or display by us of other parties’ trademarks, trade dress, or products in this prospectus supplement is not intended to, and does not, imply a relationship with, or endorsements or sponsorship of, us by the trademark or trade dress owners.

Implications of being a smaller reporting company

We are a “smaller reporting company” as defined in Item 10(f)(1) of Regulation S-K. Smaller reporting companies may take advantage of certain reduced disclosure obligations, including, among other things, providing only two years of audited financial statements and reduced disclosure obligations regarding executive compensation. We will be a smaller reporting company and may continue to take advantage of the scaled-back disclosures available to smaller reporting companies for so long as (i) the market value of our common stock held by non-affiliates is less than $250.0 million measured on the last business day of our most recently completed second fiscal quarter or (ii) at the time of determination at the end of the fiscal year, (a) our annual revenue is less than $100.0 million during the most recently completed fiscal year for which audited financial statements are then-available and (b) the market value of our common stock held by non-affiliates is less than $700.0 million measured on the last business day of our most recently completed second fiscal quarter.

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The offering

Common stock offered by us     shares of our common stock.

Option to purchase additional shares We have granted the underwriters an option to purchase up to an additional     shares of our common stock from us. This option is exercisable, in whole or in part, for a period of 30 days following the date of this prospectus supplement.

Common stock to be outstanding immediately after this offering     shares of our common stock (or     shares if the underwriters exercise their option to purchase additional shares in full).

Use of proceeds We estimate that our net proceeds from this offering will be approximately $   million, or approximately $   million if the underwriters’ option to purchase additional shares of our common stock from us is exercised in full, in each case, after deducting underwriting discounts and commissions and estimated offering expenses payable by us.

We currently intend to use the net proceeds from this offering, together with our existing cash, cash equivalents and marketable securities, to fund continued clinical and preclinical development and commercialization of pipeline assets, including CD388, as well as for working capital and general corporate purposes. See “Use of proceeds” for additional information.

Risk factors See “Risk factors” beginning on page S-6 of this prospectus supplement and other information included and incorporated by reference in this prospectus supplement and the accompanying prospectus for a discussion of factors that you should carefully consider before deciding to invest in our common stock.

Nasdaq Capital Market symbol Our common stock is listed on the Nasdaq Capital Market under the symbol “CDTX”.

The number of shares of our common stock to be outstanding immediately after this offering set forth above is based on 12,209,150 shares of our common stock outstanding as of March 31, 2025, and excludes:

• 2,813,723 shares of our common stock issuable upon the exercise of stock options outstanding as of March 31, 2025, at a weighted-average exercise price of $18.95 per share;

• 337,754 shares of our common stock issuable upon the settlement of restricted stock units outstanding as of March 31, 2025;

• 487,604 shares of our common stock issuable upon the conversion of 975,208 shares of our Series X Convertible Preferred Stock, or Series X Preferred Stock, outstanding as of March 31, 2025;

• 14,330,750 shares of our common stock issuable upon the conversion of 204,725 shares of our Series A Convertible Voting Preferred Stock, or Series A Preferred Stock, outstanding as of March 31, 2025;

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• 358,072 shares of our common stock reserved for future issuance as of March 31, 2025 under our 2024 Equity Incentive Plan, as amended, or 2024 Plan, plus an additional 2,880,000 shares of our common stock reserved for future issuance under our 2024 Plan on June 18, 2025;

• 302,578 shares of our common stock reserved for future issuance as of March 31, 2025 under our 2020 Inducement Incentive Plan, as amended, or Inducement Plan;

• 88,147 shares of our common stock reserved for future issuance as of March 31, 2025 under our 2015 Employee Stock Purchase Plan, or ESPP;

• 866 shares of our common stock issuable upon the exercise of warrants outstanding as of March 31, 2025, at a weighted-average exercise price of $230.95 per share;

• 2,491,975 shares of our common stock issuable upon the exercise of pre-funded warrants outstanding as of March 31, 2025, each at an exercise price of $0.0001 per share; and

• 177,121 shares of our common stock issued subsequent to March 31, 2025 pursuant to that certain Open Market Sale Agreement^SM, dated as May 8, 2025, or ATM Sale Agreement, with Jefferies LLC, or Jefferies, at a weighted-average sale price of $24.05 per share.

Unless otherwise indicated, all information in this prospectus supplement assumes no (i) exercise by the underwriters of their option to purchase up to an additional     shares of our common stock, (ii) exercise of stock options, warrants or pre-funded warrants listed above after March 31, 2025 and (iii) issuance of shares of common stock in connection with the settlement of restricted stock units or conversion of shares of Series A Preferred Stock or Series X Preferred Stock listed above after March 31, 2025.

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Risk factors

Investing in our common stock involves a high degree of risk. Before making an investment decision, you should carefully consider the risks described below and in our most recent Annual Report on Form 10-K and Quarterly Reports on Form 10-Q, as updated or superseded by the risks and uncertainties described in our subsequent filings under the Securities Exchange Act of 1934, as amended, or Exchange Act, each of which is incorporated by reference into this prospectus supplement and the accompanying prospectus, and all of the other information in this prospectus supplement and the accompanying prospectus, including our consolidated financial statements and related notes incorporated by reference in this prospectus supplement and the accompanying prospectus. If any of these risks is realized, our business, financial condition, results of operations and prospects could be harmed. In that event, the trading price of our common stock could decline, and you could lose part or all of your investment. Additional risks and uncertainties that are not yet identified or that we think are immaterial may also harm our business, operating results and financial condition and could result in a complete loss of your investment.

Risks related to this offering

Our management team will have broad discretion to use the net proceeds from this offering and its investment of these proceeds may not yield a favorable return.

Our management team will have broad discretion in the application of the net proceeds from this offering and could spend or invest the proceeds in ways with which our stockholders disagree. Accordingly, investors will need to rely on our management team’s judgment with respect to the use of these proceeds. We intend to use the proceeds from this offering in the manner described in the section titled “Use of proceeds.” The failure by management to apply these funds effectively could negatively affect our ability to operate and grow our business. We cannot specify with certainty all of the particular uses for the net proceeds to be received upon the completion of this offering. In addition, the amount, allocation and timing of our actual expenditures will depend upon numerous factors, including any milestone payments received or paid in connection with any future strategic partnerships and royalties on sales of any future approved product. Accordingly, we will have broad discretion in using these proceeds. Until the net proceeds are used, they may be placed in investments that do not produce significant income or that may lose value.

If you purchase common stock in this offering, you will experience immediate and substantial dilution of your investment.

The price of our common stock in this offering may be higher than the net tangible book value per share of our common stock. Therefore, if you purchase shares of our common stock in this offering, you may pay a price per share that substantially exceeds our net tangible book value per share. Based on the public offering price of $       per share, our as adjusted net tangible book value as of March 31, 2025 would have been $       million, or $       per share, representing an immediate increase in the net tangible book value per share of $       to existing stockholders and an immediate dilution of $       in net tangible book value per share to new investors purchasing our common stock in this offering, representing the difference between our as adjusted net tangible book value per share after giving effect to this offering and the public offering price. To the extent outstanding stock options, warrants or pre-funded warrants are exercised, outstanding restricted stock units vest and settle or outstanding shares of Series A Preferred Stock or Series X Preferred Stock are converted into common stock, there will be further dilution to new investors. In addition, to the extent we need to raise additional capital in the future and we issue additional shares of our common stock or securities convertible or exchangeable for our common stock, our then existing stockholders may experience dilution and the new securities may have rights senior to those of our common stock offered in this offering.

Further, pursuant to the sales agreement prospectus, we may issue and sell from time to time through Jefferies shares of our common stock, in an aggregate amount not to exceed $150.0 million. As of the date of this

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prospectus supplement, $145.74 million of our common stock remains available for sale under the sales agreement prospectus. To the extent that we sell shares of our common stock pursuant to the ATM Sale Agreement subsequent to this offering, investors purchasing securities in this offering could experience further dilution.

We do not currently intend to pay dividends on our common stock, and any return to investors is expected to come, if at all, only from potential increases in the price of our common stock.

We have never declared or paid cash dividends on our capital stock, and you should not rely on an investment in our common stock to provide dividend income. We currently intend to retain all of our future earnings, if any, to finance the growth and development of our business and do not anticipate declaring or paying any cash dividends for the foreseeable future. As a result, capital appreciation, if any, of our common stock will be your sole source of gain for the foreseeable future.

The trading price of the shares of our common stock could be highly volatile, and purchasers of our common stock could incur substantial losses.

The price of our common stock is highly volatile and may be affected by developments directly affecting our business, as well as by developments out of our control or not specific to us. The pharmaceutical and biotechnology industries, in particular, and the stock market generally, are vulnerable to abrupt changes in investor sentiment. Prices of securities and trading volumes of companies in the pharmaceutical and biotechnology industries, including ours, can swing dramatically in ways unrelated to, or that bear a disproportionate relationship to, our performance. This volatility may affect the price at which you could sell the shares of our common stock, and the sale of substantial amounts of our common stock could adversely affect the price of our common stock. Our stock price is likely to continue to be volatile and subject to significant price and volume fluctuations in response to market and other factors, including those described in the sections captioned “Risk factors” in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein.

As a result, you may not be able to sell your shares of common stock at or above the price at which you purchase them. In addition, the stock market in general, and Nasdaq and the stock of pharmaceutical and bio pharmaceutical companies in particular, have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of these companies. Broad market and industry factors may negatively affect the market price of our common stock, regardless of our actual operating performance.

We need additional funding to advance CD388 through a planned Phase 3 trial and to fund our continued business operations. Securing additional funding may be a lengthy and difficult process and may restrict our operations or require us to relinquish rights to our technologies or product candidates.

Our ability to advance CD388 through our planned Phase 3 trial, begin commercialization, pending FDA approval, and continue our business operations is dependent on our ability to obtain additional funding. Accordingly, we are actively pursuing additional sources of financing, which may include debt, royalty financing or other sources. While we believe such additional financing will be available to us, there can be no assurance that we will be able to conduct a debt, royalty or other financing transaction on terms and conditions acceptable to us, or at all. The global credit and financial markets have recently experienced extreme volatility and

disruptions, including diminished liquidity and credit availability, declines in consumer confidence, declines in economic growth, increases in unemployment rates and uncertainty about economic stability. If the equity and credit markets continue to deteriorate, it may make any additional debt financing more difficult, more costly and more dilutive. In addition, we may not be able to access a portion of our existing cash, cash equivalents and restricted cash due to market conditions such as potential future disruptions in access to bank deposits or lending commitments due to bank failures, which could have a material adverse effect on our business and financial

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condition. In addition, if the financial market disruptions and economic slowdown deepen or persist, we may not be able to access additional capital on favorable terms, or at all, which could negatively affect our financial condition and our ability to pursue our business strategy. Accordingly, you should not assume that we will successfully consummate any such additional financing transaction.

In addition, debt financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends and may be secured by all or a portion of our assets. If we raise funds by entering into a royalty financing or other collaborations, strategic alliances or licensing arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or to grant licenses on terms that may not be favorable to us.

If we are unable to raise additional funds through debt or other financing structures, or through royalty financing, collaborations, strategic alliances or licensing arrangements with third parties, we may be required to delay, reduce or terminate our advancement of CD388 or our other Cloudbreak programs for non-influenza DFCs, or be forced to grant rights in CD388 or our other Cloudbreak programs for non-influenza DFCs that we would otherwise prefer to retain for ourselves.

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Special note regarding forward-looking statements

This prospectus supplement and accompanying prospectus, including the information incorporated by reference herein and therein, contain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Exchange Act, and the Private Securities Litigation Reform Act of 1995, as amended, that involve substantial risks and uncertainties. All statements contained in this prospectus supplement and accompanying prospectus regarding future events, results or outcomes, including our future results of operations and financial position, are forward-looking statements. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. These forward-looking statements include statements regarding:

• our anticipated timing for preclinical development, regulatory submissions, and commencement and completion of clinical trials for CD388 and other development candidates;

• our plans to develop and commercialize our product candidates;

• our ability to fund our working capital requirements, including our ability to obtain additional funding;

• our expected clinical trial designs and regulatory pathways for CD388;

• our ability to obtain and maintain regulatory approval of our product candidates and any related restrictions, limitations, and/or warnings in the label of an approved product candidate;

• our ability to successfully commercialize, and our expectations regarding future therapeutic and commercial potential with respect to, our product candidates;

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

• the rate and degree of market acceptance of our products that are approved;

• our ability to develop sales and marketing capabilities, whether alone or with collaborators;

• regulatory developments in the United States and foreign countries;

• the performance of our third-party suppliers and manufacturers;

• the success of competing therapies that are or may become available;

• our expectations for the attributes of our development candidates, including pharmaceutical properties, efficacy, safety and dosing regimens;

• our estimates of our expenses, ongoing losses, future revenue, capital requirements and our needs for or ability to obtain additional financing;

• our ability to obtain and maintain intellectual property protection for our product candidates;

• our ability to use our Cloudbreak platform to identify development candidates, or to expand our Cloudbreak platform to other areas of infective disease and oncology;

• our ability to identify and develop new product candidates;

• our ability to retain and recruit key personnel;

• our financial performance;

• developments and projections relating to our competitors or our industry;

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• the potential impact of broader macroeconomic conditions, including current or future tariffs, pandemics, inflation, bank failures, labor shortages, supply chain disruptions, recession risks and potential disruptions from the ongoing Russia-Ukraine conflict and related sanctions and the Israel-Hamas war; and

• our use of the net proceeds from this offering.

In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “could,” “intend,” “target,” “project,” “contemplates,” “believes,” “estimates,” “predicts,” “potential” or “continue” or the negative of these terms or other similar expressions. The forward-looking statements in this prospectus supplement and accompanying prospectus are only predictions. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our business, financial condition and results of operations. These forward-looking statements speak only as of the date of this prospectus supplement, the accompanying prospectus or the documents incorporated by reference in this prospectus supplement, as applicable, and are subject to a number of risks, uncertainties and assumptions described under the sections in this prospectus supplement, accompanying prospectus and the documents incorporated by reference herein under the captions “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” and elsewhere in this prospectus supplement, accompanying prospectus and the documents incorporated by reference herein. Because forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified and some of which are beyond our control, you should not rely on these forward-looking statements as predictions of future events. The events and circumstances reflected in our forward-looking statements may not be achieved or occur and actual results could differ materially from those projected in the forward-looking statements. Moreover, we operate in an evolving environment. New risk factors and uncertainties may emerge from time to time, and it is not possible for management to predict all risk factors and uncertainties. Except as required by applicable law, we undertake no obligation to publicly update or revise any forward-looking statements contained or incorporated by reference herein, whether as a result of any new information, future events, changed circumstances or otherwise. You should, however, review the factors and risks we describe in the reports we will file from time to time with the SEC after the date of this prospectus supplement. See the section titled “Where you can find more information.” For all forward-looking statements, we claim the protection of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995.

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

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Use of proceeds

We estimate that the net proceeds to us from this offering will be approximately $      million, or approximately $      million if the underwriters exercise their option to purchase additional shares of our common stock in full, in each case, after deducting underwriting discounts and commissions and estimated offering expenses payable by us.

We currently intend to use the net proceeds of this offering, together with our existing cash, cash equivalents and restricted cash, to fund continued clinical and preclinical development and commercialization of pipeline assets, including CD388, as well as for working capital and general corporate purposes.

Pending the use of net proceeds, we intend to invest the net proceeds in short-term, investment-grade, interest bearing instruments in accordance with our investment policy.

The amounts and timing of our actual expenditures will depend on numerous factors, including the time and cost necessary to conduct our preclinical studies and planned clinical trials, the results of such preclinical studies and clinical trials and other factors described in the section titled “Risk factors” in this prospectus supplement and the accompanying prospectus, including the information incorporated by reference herein and therein, as well as the amount of cash used in our operations and any unforeseen cash needs. Therefore, our actual expenditures may differ materially from the estimates described above. We may find it necessary or advisable to use the net proceeds for other purposes, and we will have broad discretion in the application of the net proceeds.

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Dilution

As of March 31, 2025, we had a historical net tangible book value of approximately $141.7 million, or $9.64 per share of common stock. Our historical net tangible book value per share represents total tangible assets less total liabilities, divided by the number of shares of our common stock outstanding at March 31, 2025 after giving effect to the exercise in full of 2,491,975 shares of common stock issuable upon exercise of pre-funded warrants that were outstanding on March 31, 2025 at an exercise price of $0.0001 per share.

After giving effect to the issuance and sale by us of      shares of our common stock in this offering at the public offering price of $       per share (which assumes the exercise in full of 2,491,975 shares issuable upon exercise of pre-funded warrants that were outstanding on March 31, 2025 at an exercise price of $0.0001 per share), after deducting underwriting discounts and commissions and estimated offering expenses payable by us, our as adjusted net tangible book value as of March 31, 2025 would have been approximately $       million, or approximately $       per share. This amount represents an immediate increase in our net tangible book value of approximately $       per share to our existing stockholders and an immediate dilution in our net tangible book value of approximately $       per share to new investors purchasing our common stock in this offering. We determine dilution by subtracting our as adjusted net tangible book value per share after this offering from the public offering price per share paid by new investors. The following table illustrates this dilution on a per share basis to the new investors purchasing our common stock in this offering without giving effect to exercise by the underwriters of their option to purchase additional shares of our common stock:

Public offering price per share						$
Historical net tangible book value per share as of March 31, 2025		$	9.64
Increase in net tangible book value per share attributable to new investors purchasing shares in this offering		$
As adjusted net tangible book value per share, after giving effect to this offering						$
Dilution in net tangible book value per share to new investors purchasing shares in this offering						$

If the underwriters exercise in full their option to purchase additional shares of our common stock at the public offering price of $       per share, the as adjusted net tangible book value per share after this offering would be approximately $      , representing an increase in the as adjusted net tangible book value of approximately $       per share to our existing stockholders and immediate dilution to new investors purchasing our common stock in this offering at the public offering price of approximately $       per share.

Except as noted otherwise, the above discussion and table are based on an aggregate of 12,209,159 shares of our common stock outstanding as of March 31, 2025 and the assumed exercise of 2,491,975 shares issuable upon exercise of pre-funded warrants outstanding as of March 31, 2025, but excludes:

• 2,813,723 shares of our common stock issuable upon the exercise of stock options outstanding as of March 31, 2025, at a weighted-average exercise price of $18.95 per share;

• 337,754 shares of our common stock issuable upon the settlement of restricted stock units outstanding as of March 31, 2025;

• 487,604 shares of our common stock issuable upon the conversion of 975,208 shares of our Series X Preferred Stock outstanding as of March 31, 2025;

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• 14,330,750 shares of our common stock issuable upon the conversion of 204,725 shares of our Series A Preferred Stock outstanding as of March 31, 2025;

• 358,072 shares of our common stock reserved for future issuance as of March 31, 2025 under our 2024 Plan, plus an additional 2,880,000 shares of our common stock reserved for future issuance under our 2024 Plan on June 18, 2025;

• 302,578 shares of our common stock reserved for future issuance as of March 31, 2025 under our Inducement Plan;

• 88,147 shares of our common stock reserved for future issuance as of March 31, 2025 under our ESPP;

• 866 shares of our common stock issuable upon the exercise of warrants outstanding as of March 31, 2025, at a weighted-average exercise price of $230.95 per share; and

• 177,121 shares of our common stock issued subsequent to March 31, 2025 pursuant to the ATM Sale Agreement with Jefferies.

To the extent that any stock options or warrants outstanding as of March 31, 2025 have been or may be exercised or other shares issued, including upon the settlement of outstanding restricted stock units or conversion of shares of Series A Preferred Stock or Series X Preferred Stock, investors purchasing our common stock in this offering may experience further dilution. In addition, we may choose to raise additional capital due to market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans, including through our ATM Sale Agreement, which may result in further dilution to our stockholders.

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Underwriting

We are offering the shares of common stock described in this prospectus through a number of underwriters. J.P. Morgan Securities LLC, Morgan Stanley & Co. LLC, Guggenheim Securities, LLC and Cantor Fitzgerald & Co. are acting as joint book-running managers of the offering and as representatives of the underwriters. We have entered into an underwriting agreement with the underwriters. Subject to the terms and conditions of the underwriting agreement, we have agreed to sell to the underwriters, and each underwriter has severally agreed to purchase, at the public offering price less the underwriting discounts and commissions set forth on the cover page of this prospectus, the number of shares of common stock listed next to its name in the following table:

Name		Number of shares
J.P. Morgan Securities LLC
Morgan Stanley & Co. LLC
Guggenheim Securities, LLC
Cantor Fitzgerald & Co.
Total

The underwriters are committed to purchase all of the shares of common stock offered by us if they purchase any shares. The underwriting agreement also provides that if an underwriter defaults, the purchase commitments of non-defaulting underwriters may also be increased or the offering may be terminated.

The underwriters propose to offer the shares of common stock directly to the public at the initial public offering price set forth on the cover page of this prospectus and to certain dealers at that price less a concession not in excess of $    per share. Any such dealers may resell shares to certain other brokers or dealers at a discount of up to $    per share from the initial public offering price. After the initial offering of the shares to the public, the offering price and the other selling terms may be changed by the underwriters. The offering of the shares by the underwriters is subject to receipt and acceptance and subject to the underwriters’ right to reject any order in whole or in part. Sales of shares made outside of the United States may be made by affiliates of the underwriters.

The underwriters have an option to buy up to      additional shares of common stock from us to cover sales of shares by the underwriters which exceed the number of shares specified in the table above. The underwriters have 30 days from the date of this prospectus to exercise this option to purchase additional shares. If any shares are purchased with this option to purchase additional shares, the underwriters will purchase shares in approximately the same proportion as shown in the table above. If any additional shares of common stock are purchased, the underwriters will offer the additional shares on the same terms as those on which the shares are being offered.

The underwriting fee is equal to the public offering price per share of common stock less the amount paid by the underwriters to us per share of common stock. The underwriting fee is $    per share. The following table shows the per share total underwriting discounts and commissions to be paid to the underwriters assuming both no exercise and full exercise of the underwriters’ option to purchase additional shares.

		Without option to purchase additional shares exercise				With full option to purchase additional shares exercise
Per share		$				$
Total		$				$

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We estimate that the total expenses of this offering, including registration, filing and listing fees, printing fees and legal and accounting expenses, but excluding the underwriting discounts and commissions, will be approximately $     .

A prospectus in electronic format may be made available on the web sites maintained by one or more underwriters, or selling group members, if any, participating in the offering. The underwriters may agree to allocate a number of shares to underwriters and selling group members for sale to their online brokerage account holders. Internet distributions will be allocated by the representatives to underwriters and selling group members that may make Internet distributions on the same basis as other allocations.

We, our officers and our directors have agreed, subject to certain specified exceptions, not to directly or indirectly, for a period of 60 days after the date of the underwriting agreement:

• sell, offer, contract or grant any option to sell (including any short sale), pledge, transfer, establish an open “put equivalent position” within the meaning of Rule 16a-l(h) under the Exchange Act, or

• otherwise dispose of, any shares of common stock, options or warrants to acquire shares of common stock, or securities exchangeable or exercisable for or convertible into shares of common stock currently or hereafter owned either of record or beneficially,

• enter into any swap, hedge or other agreement or transaction that transfers, in whole or in part, the economic consequence of ownership of common stock, or securities exchangeable or exercisable for or convertible into shares of common stock, or

• publicly announce an intention to do any of the foregoing for a period of 60 days after the date of this prospectus without the prior written consent of J.P. Morgan Securities LLC and Morgan Stanley & Co. LLC.

In addition, we and each such person agrees that, without the prior written consent of J.P. Morgan Securities LLC and Morgan Stanley & Co. LLC, we or such other person will not, during the restricted period, make any demand for, or exercise any right with respect to, the registration of any shares of common stock or any security convertible into or exercisable or exchangeable for common stock.

The underwriters may, in their sole discretion and at any time or from time to time before the termination of the 60-day period release all or any portion of the securities subject to lock-up agreements.

We have agreed to indemnify the underwriters against certain liabilities, including liabilities under the Securities Act of 1933.

Our common stock is listed/quoted on the Nasdaq Capital Market under the trading symbol “CDTX.”

In connection with this offering, the underwriters may engage in stabilizing transactions, which involves making bids for, purchasing and selling shares of common stock in the open market for the purpose of preventing or retarding a decline in the market price of the common stock while this offering is in progress. These stabilizing transactions may include making short sales of common stock, which involves the sale by the underwriters of a greater number of shares of common stock than they are required to purchase in this offering, and purchasing shares of common stock on the open market to cover positions created by short sales. Short sales may be “covered” shorts, which are short positions in an amount not greater than the underwriters’ option to purchase additional shares referred to above, or may be “naked” shorts, which are short positions in excess of that amount. The underwriters may close out any covered short position either by exercising their option to purchase additional shares, in whole or in part, or by purchasing shares in the open market. In making this determination, the underwriters will consider, among other things, the price of shares available for purchase in the open market compared to the price at which the underwriters may purchase shares through the option to purchase additional shares. A naked short position is more likely to be created if the underwriters are concerned that there may be

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downward pressure on the price of the common stock in the open market that could adversely affect investors who purchase in this offering. To the extent that the underwriters create a naked short position, they will purchase shares in the open market to cover the position.

The underwriters have advised us that, pursuant to Regulation M of the Securities Act of 1933, they may also engage in other activities that stabilize, maintain or otherwise affect the price of the common stock, including the imposition of penalty bids. This means that if the representatives of the underwriters purchase common stock in the open market in stabilizing transactions or to cover short sales, the representatives can require the underwriters that sold those shares as part of this offering to repay the underwriting discount received by them.

These activities may have the effect of raising or maintaining the market price of the common stock or preventing or retarding a decline in the market price of the common stock, and, as a result, the price of the common stock may be higher than the price that otherwise might exist in the open market. If the underwriters commence these activities, they may discontinue them at any time. The underwriters may carry out these transactions on the Nasdaq Capital Market, in the over-the-counter market or otherwise.

In addition, in connection with this offering certain of the underwriters may engage in passive market making transactions in our common stock on The Nasdaq Capital Market prior to the pricing and completion of this offering. Passive market making consists of displaying bids on The Nasdaq Capital Market no higher than the bid prices of independent market makers and making purchases at prices no higher than these independent bids and effected in response to order flow. Net purchases by a passive market maker on each day are generally limited to a specified percentage of the passive market maker’s average daily trading volume in the common stock during a specified period and must be discontinued when such limit is reached. Passive market making may cause the price of our common stock to be higher than the price that otherwise would exist in the open market in the absence of these transactions. If passive market making is commenced, it may be discontinued at any time.

Other than in the United States, no action has been taken by us or the underwriters that would permit a public offering of the shares of common stock offered by this prospectus in any jurisdiction where action for that purpose is required. The shares of common stock offered by this prospectus may not be offered or sold, directly or indirectly, nor may this prospectus or any other offering material or advertisements in connection with the offer and sale of any such shares of common stock be distributed or published in any jurisdiction, except under circumstances that will result in compliance with the applicable rules and regulations of that jurisdiction. Persons into whose possession this prospectus comes are advised to inform themselves about and to observe any restrictions relating to the offering and the distribution of this prospectus. This prospectus does not constitute an offer to sell or a solicitation of an offer to buy any shares of common stock offered by this prospectus in any jurisdiction in which such an offer or a solicitation is unlawful.

Selling restrictions

General

Other than in the United States, no action has been taken by us or the underwriters that would permit a public offering of the securities offered by this prospectus in any jurisdiction where action for that purpose is required. The securities offered by this prospectus may not be offered or sold, directly or indirectly, nor may this prospectus or any other offering material or advertisements in connection with the offer and sale of any such securities be distributed or published in any jurisdiction, except under circumstances that will result in compliance with the applicable rules and regulations of that jurisdiction. Persons into whose possession this prospectus comes are advised to inform themselves about and to observe any restrictions relating to the offering and the distribution of this prospectus. This prospectus does not constitute an offer to sell or a solicitation of an offer to buy any securities offered by this prospectus in any jurisdiction in which such an offer or a solicitation is unlawful.

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European Economic Area

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

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

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

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

provided that no such offer of shares shall require us or any underwriter to publish a prospectus pursuant to Article 3 of the Prospectus Regulation or supplement a prospectus pursuant to Article 23 of the Prospectus Regulation. and each person who initially acquires any shares or to whom any offer is made will be deemed to have represented, acknowledged and agreed to and with each of the underwriters and the Company that it is a “qualified investor” within the meaning of Article 2(e) of the Prospectus Regulation. In the case of any shares being offered to a financial intermediary as that term is used in the Prospectus Regulation, each such financial intermediary will be deemed to have represented, acknowledged and agreed that the shares acquired by it in the offer have not been acquired on a non-discretionary basis on behalf of, nor have they been acquired with a view to their offer or resale to, persons in circumstances which may give rise to an offer of any shares to the public other than their offer or resale in a Relevant State to qualified investors as so defined or in circumstances in which the prior consent of the underwriters have been obtained to each such proposed offer or resale.

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

United Kingdom

No shares have been offered or will be offered pursuant to the offering to the public in the United Kingdom prior to the publication of a prospectus in relation to the shares which is to be treated as if it had been approved by the Financial Conduct Authority in accordance with the transitional provisions in Article 74 (transitional provisions) of the Prospectus Amendment etc (EU Exit) Regulations 2019/1234, except that the shares may be offered to the public in the United Kingdom at any time:

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

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

C. in any other circumstances falling within Section 86 of the FSMA.

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

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In addition, in the United Kingdom, this document is being distributed only to, and is directed only at, and any offer subsequently made may only be directed at persons who are “qualified investors” (as defined in the Prospectus Regulation) (i) who have professional experience in matters relating to investments falling within Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005, as amended, or the Order, and/or (ii) who are high net worth companies (or persons to whom it may otherwise be lawfully communicated) falling within Article 49(2)(a) to (d) of the Order (all such persons together being referred to as “relevant persons”) or otherwise in circumstances which have not resulted and will not result in an offer to the public of the shares in the United Kingdom within the meaning of the Financial Services and Markets Act 2000.

Any person in the United Kingdom that is not a relevant person should not act or rely on the information included in this document or use it as basis for taking any action. In the United Kingdom, any investment or investment activity that this document relates to may be made or taken exclusively by relevant persons.

Switzerland

This prospectus does not constitute an offer to the public or a solicitation to purchase or invest in any shares. No shares have been offered or will be offered to the public in Switzerland, except that offers of shares may be made to the public in Switzerland at any time under the following exemptions under the Swiss Financial Services Act, or FinSA:

A. to any person which is a professional client as defined under the FinSA;

B. to fewer than 500 persons (other than professional clients as defined under the FinSA), subject to obtaining the prior consent of joint global coordinators/lead managers for any such offer; or

C. in any other circumstances falling within Article 36 FinSA in connection with Article 44 of the Swiss Financial Services Ordinance,

provided that no such offer of shares shall require the Company or any investment bank to publish a prospectus pursuant to Article 35 FinSA.

The shares have not been and will not be listed or admitted to trading on a trading venue in Switzerland.

Neither this document nor any other offering or marketing material relating to the shares constitutes a prospectus as such term is understood pursuant to the FinSA and neither this document nor any other offering or marketing material relating to the shares may be publicly distributed or otherwise made publicly available in Switzerland.

Canada

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

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

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

Japan

The shares have not been and will not be registered pursuant to Article 4, Paragraph 1 of the Financial Instruments and Exchange Act. Accordingly, none of the shares nor any interest therein may be offered or sold, directly or indirectly, in Japan or to, or for the benefit of, any “resident” of Japan (which term as used herein means any person resident in Japan, including any corporation or other entity organized under the laws of Japan), or to others for re-offering or resale, directly or indirectly, in Japan or to or for the benefit of a resident of Japan, except pursuant to an exemption from the registration requirements of, and otherwise in compliance with, the Financial Instruments and Exchange Act and any other applicable laws, regulations and ministerial guidelines of Japan in effect at the relevant time.

Hong Kong

The shares have not been offered or sold and will not be offered or sold in Hong Kong, by means of any document, other than (a) to “professional investors” as defined in the Securities and Futures Ordinance (Cap. 571 of the Laws of Hong Kong), or the SFO, of Hong Kong and any rules made thereunder; or (b) in other circumstances which do not result in the document being a “prospectus” as defined in the Companies (Winding Up and Miscellaneous Provisions) Ordinance (Cap. 32) of Hong Kong), or the CO, or which do not constitute an offer to the public within the meaning of the CO. No advertisement, invitation or document relating to the shares has been or may be issued or has been or may be in the possession of any person for the purposes of issue, whether in Hong Kong or elsewhere, which is directed at, or the contents of which are likely to be accessed or read by, the public of Hong Kong (except if permitted to do so under the securities laws of Hong Kong) other than with respect to shares which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” as defined in the SFO and any rules made thereunder.

Singapore

Each underwriter has acknowledged that this prospectus has not been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, each underwriter has represented and agreed that it has not offered or sold any shares or caused the shares to be made the subject of an invitation for subscription or purchase and will not offer or sell any shares or cause the shares to be made the subject of an invitation for subscription or purchase, and has not circulated or distributed, nor will it circulate or distribute, this prospectus or any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the shares, whether directly or indirectly, to any person in Singapore other than:

A. to an institutional investor (as defined in Section 4A of the Securities and Futures Act (Chapter 289) of Singapore, as modified or amended from time to time, or SFA) pursuant to Section 274 of the SFA;

B. to a relevant person (as defined in Section 275(2) of the SFA) pursuant to Section 275(1) of the SFA, or any person pursuant to Section 275(1A) of the SFA, and in accordance with the conditions specified in Section 275 of the SFA; or

C. otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA.

Where the shares are subscribed or purchased under Section 275 of the SFA by a relevant person which is:

A. a corporation (which is not an accredited investor (as defined in Section 4A of the SFA)) the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor; or

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B. a trust (where the trustee is not an accredited investor) whose sole purpose is to hold investments and each beneficiary of the trust is an individual who is an accredited investor,

securities or securities-based derivatives contracts (each term as defined in Section 2(1) of the SFA) of that corporation or the beneficiaries’ rights and interest (howsoever described) in that trust shall not be transferred within six months after that corporation or that trust has acquired the shares pursuant to an offer made under Section 275 of the SFA except:

A. to an institutional investor or to a relevant person, or to any person arising from an offer referred to in Section 275(1A) or Section 276(4)(c)(ii) of the SFA;

B. where no consideration is or will be given for the transfer;

C. where the transfer is by operation of law;

D. as specified in Section 276(7) of the SFA; or

E. as specified in Regulation 37A of the Securities and Futures (Offers of Investments) (Securities and Securities-based Derivatives Contracts) Regulations 2018.

Notice to prospective investors in Australia

This prospectus:

• does not constitute a disclosure document or a prospectus under Chapter 6D.2 of the Corporations Act 2001 (Cth), or the Corporations Act;

• has not been, and will not be, lodged with the Australian Securities and Investments Commission, or ASIC, as a disclosure document for the purposes of the Corporations Act and does not purport to include the information required of a disclosure document for the purposes of the Corporations Act; and

• may only be provided in Australia to select investors who are able to demonstrate that they fall within one or more of the categories of investors, available under section 708 of the Corporations Act, or the Exempt Investors.

The shares may not be directly or indirectly offered for subscription or purchased or sold, and no invitations to subscribe for or buy the shares may be issued, and no draft or definitive offering memorandum, advertisement or other offering material relating to any shares may be distributed in Australia, except where disclosure to investors is not required under Chapter 6D of the Corporations Act or is otherwise in compliance with all applicable Australian laws and regulations. By submitting an application for the shares, you represent and warrant to us that you are an Exempt Investor.

As any offer of shares under this document will be made without disclosure in Australia under Chapter 6D.2 of the Corporations Act, the offer of those shares for resale in Australia within 12 months may, under section 707 of the Corporations Act, require disclosure to investors under Chapter 6D.2 if none of the exemptions in section 708 applies to that resale. By applying for the shares you undertake to us that you will not, for a period of 12 months from the date of sale, offer, transfer, assign or otherwise alienate those shares to investors in Australia except in circumstances where disclosure to investors is not required under Chapter 6D.2 of the Corporations Act or where a compliant disclosure document is prepared and lodged with ASIC.

Notice to prospective investors in Israel

This document does not constitute a prospectus under the Israeli Securities Law, 5728-1968, and has not been filed with or approved by the Israel Securities Authority. In Israel, this prospectus is being distributed only to, and is directed only at, qualified investors listed in the first addendum, or the Addendum, to the Israeli

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Securities Law. Qualified investors may be required to submit written confirmation that they fall within the scope of the Addendum. In addition, we may distribute and direct this document in Israel, at our sole discretion, to investors who are not considered qualified investors, provided that the number of such investors in Israel shall be no greater than 35 in any 12-month period.

Certain of the underwriters and their affiliates have provided in the past to us and our affiliates and may provide from time to time in the future certain commercial banking, financial advisory, investment banking and other services for us and such affiliates in the ordinary course of their business, for which they have received and may continue to receive customary fees and commissions. In addition, from time to time, certain of the underwriters and their affiliates may effect transactions for their own account or the account of customers, and hold on behalf of themselves or their customers, long or short positions in our debt or equity securities or loans, and may do so in the future.

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Legal matters

Cooley LLP, San Diego, California, which has acted as our counsel in connection with this offering, will pass upon the validity of the shares of common stock offered hereby. Latham & Watkins, LLP, San Diego, California has acted as counsel to the underwriters in connection with this offering.

Experts

Ernst & Young LLP, independent registered public accounting firm, has audited our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2024, as set forth in their report, which is incorporated by reference into this prospectus supplement and elsewhere in the registration statement. Our financial statements are incorporated by reference in reliance on Ernst & Young LLP’s report, given on their authority as experts in accounting and auditing.

Where you can find more information

This prospectus supplement and the accompanying prospectus are part of a registration statement on Form S-3 we filed with the SEC under the Securities Act and do not contain all of the information set forth in the registration statement and the exhibits thereto. Whenever a reference is made in this prospectus supplement or the accompanying prospectus to any of our contracts, agreements or other documents, the reference may not be complete, and you should refer to the exhibits that are a part of the registration statement or the exhibits to the reports or other documents incorporated by reference therein. For further information with respect to us and our common stock we are offering under this prospectus supplement, 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.

Copies of certain information filed by us with the SEC are also available on our website at www.cidara.com. Information contained in or accessible through our website does not constitute a part of this prospectus supplement or the accompanying prospectus and is not incorporated by reference into this prospectus supplement or the accompanying prospectus.

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Incorporation of certain information by reference

The SEC allows us to “incorporate by reference” information from other documents that we file with it, which means that we can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectus supplement or the accompanying prospectus. The information incorporated by reference is considered to be part of this prospectus supplement and the accompanying prospectus, and later information that we file with the SEC (Commission File No. 001-36912) will automatically update and supersede this information. We incorporate by reference the documents listed below and any future filings made by us with the SEC (other than Current Reports or portions thereof furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items and other portions of documents that are furnished, but not filed, or are otherwise not incorporated into registration statements pursuant to applicable rules promulgated by the SEC) that are filed by us with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after this prospectus supplement but prior to the termination of the offering covered by this prospectus supplement:

• our Annual Report on Form 10-K for the fiscal year ended December 31, 2024, filed with the SEC on March 6, 2025;

• the information specifically incorporated by reference into our Annual Report on Form 10-K for the fiscal year ended December  31, 2024 from our definitive proxy statement on Schedule 14A, filed with the SEC on April 25, 2025;

• our Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2025, filed with the SEC on May 8, 2025;

• our Current Reports on Form 8-K, filed with the SEC on January  7, 2025, February  18, 2025, and June 23, 2025; and

• the description of our common stock which is contained in our registration statement on Form 8-A filed on April 9, 2015 under the Exchange Act, as updated by the description of our common stock contained as Exhibit 4.5 to our Annual Report on Form 10-K for the fiscal year ended December  31, 2024, filed with the SEC on March 6, 2025, including any amendment or report filed for the purpose of updating such description.

We will provide to each person, including any beneficial owner, to whom a prospectus supplement or the underlying prospectus is delivered, without charge upon the written or oral request, a copy of any or all of the documents that are incorporated by reference into this prospectus supplement but not delivered with the prospectus, including exhibits that are specifically incorporated by reference into such documents. You should direct any requests for documents to Cidara Therapeutics, Inc., Attn: Corporate Secretary, 6310 Nancy Ridge Drive, Suite 101, San Diego, California 92121; telephone: (858) 752-6170.

Any statement contained herein or in a document incorporated or deemed to be incorporated by reference into this document will be deemed to be modified or superseded for purposes of the document to the extent that a statement contained in this document or any other subsequently filed document that is deemed to be incorporated by reference into this document modifies or supersedes the statement.

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PROSPECTUS

$500,000,000

Common Stock

Preferred Stock

Debt Securities

Warrants

From time to time, we may offer and sell up to $500,000,000 of any combination of the securities described in this prospectus in one or more offerings. We may also offer securities as may be issuable upon conversion, redemption, repurchase, exchange or exercise of any securities registered hereunder, including any applicable anti-dilution provisions.

This prospectus provides a general description of the securities we may offer. Each time we offer securities, we will provide specific terms of the securities offered in a supplement to this prospectus. We may also authorize one or more free writing prospectuses to be provided to you in connection with these offerings. The prospectus supplement and any related free writing prospectus may also add, update or change information contained in this prospectus. You should carefully read this prospectus, the applicable prospectus supplement and any related free writing prospectus, as well as any documents incorporated by reference, before you invest in any of the securities being offered.

This prospectus may not be used to consummate a sale of any securities unless accompanied by a prospectus supplement.

We may sell these securities directly to investors, through agents designated from time to time or to or through underwriters or dealers, on a continuous or delayed basis. For additional information on the methods of sale, you should refer to the section entitled “Plan of Distribution” in this prospectus. If any agents or underwriters are involved in the sale of any securities with respect to which this prospectus is being delivered, the names of such agents or underwriters and any applicable fees, commissions, discounts or options to purchase additional securities will be set forth in a prospectus supplement. The price to the public of such securities and the net proceeds we expect to receive from such sale will also be set forth in a prospectus supplement.

Our common stock is traded on The Nasdaq Capital Market under the symbol “CDTX.” On May 7, 2025, the last reported sale price of our common stock was $18.98 per share. The applicable prospectus supplement will contain information, where applicable, as to any other listing on The Nasdaq Capital Market or any securities market or other exchange of the securities, if any, covered by the prospectus supplement.

We are a “smaller reporting company” as defined under federal securities laws and, as such, have elected to comply with certain reduced public company reporting requirements. See “Summary—Implications of Being a Smaller Reporting Company.”

Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading “Risk Factors” contained in the applicable prospectus supplement and any related free writing prospectus we have authorized for use in connection with a specific offering, and under similar headings in the other documents that are incorporated by reference into this prospectus as described on page 6 of this prospectus.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED IF THIS PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

The date of this prospectus is May 15, 2025.

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TABLE OF CONTENTS

ABOUT THIS PROSPECTUS			i
SUMMARY			1
RISK FACTORS			6
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS			7
USE OF PROCEEDS			9
DESCRIPTION OF CAPITAL STOCK			10
DESCRIPTION OF DEBT SECURITIES			15
DESCRIPTION OF WARRANTS			22
LEGAL OWNERSHIP OF SECURITIES			25
PLAN OF DISTRIBUTION			29
LEGAL MATTERS			31
EXPERTS			31
WHERE YOU CAN FIND MORE INFORMATION			31
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE			32

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ABOUT THIS PROSPECTUS

This prospectus is a part of a registration statement on Form S-3 that we filed with the Securities and Exchange Commission, or SEC, utilizing a “shelf” registration process. Under this shelf registration statement, we may sell any combination of the securities described in this prospectus in one or more offerings up to a total aggregate offering price of $500,000,000. This prospectus provides you with a general description of the securities we may offer.

Each time we sell securities under this prospectus, we will provide a prospectus supplement that will contain specific information about the terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement and any related free writing prospectus that we may authorize to be provided to you may also add, update or change information contained in this prospectus or in any documents that we have incorporated by reference into this prospectus. You should read this prospectus, any applicable prospectus supplement and any related free writing prospectus, together with the information incorporated herein by reference as described under the heading “Incorporation of Certain Information by Reference,” before investing in any of the securities offered.

THIS PROSPECTUS MAY NOT BE USED TO CONSUMMATE A SALE OF SECURITIES UNLESS IT IS ACCOMPANIED BY A PROSPECTUS SUPPLEMENT.

Neither we, nor any agent, underwriter or dealer has authorized any person to give any information or to make any representation other than those contained or incorporated by reference in this prospectus, any applicable prospectus supplement or any related free writing prospectus prepared by or on behalf of us or to which we have referred you. This prospectus, any applicable supplement to this prospectus or any related free writing prospectus 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, any applicable supplement to this prospectus or any related free writing prospectus 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, any applicable prospectus supplement or any related free writing prospectus 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, any applicable prospectus supplement or any related free writing prospectus is delivered, or securities are sold, on a later date.

This prospectus and the information incorporated herein by reference contain 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 the heading “Where You Can Find More Information.”

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SUMMARY

This summary highlights selected information from this prospectus and does not contain all of the information that you need to consider in making your investment decision. You should carefully read the entire prospectus, the applicable prospectus supplement and any related free writing prospectus, including the risks of investing in our securities discussed under the heading “Risk Factors” contained in the applicable prospectus supplement and any related free writing prospectus, and under similar headings in the other documents that are incorporated by reference into this prospectus. You should also carefully read the information incorporated by reference into this prospectus, including our financial statements and related notes, and the exhibits to the registration statement of which this prospectus is a part, before making an investment decision.

Unless the context indicates otherwise, references in this prospectus to “Cidara,” “company,” “we,” “us” and “our” refer to Cidara Therapeutics, Inc.

Company Overview

We are a biotechnology company using our proprietary Cloudbreak^® platform to develop drug-Fc conjugate therapeutics designed to save lives and improve the standard of care for patients facing serious diseases.

Our lead clinical-stage asset is CD388, a novel long-acting antiviral which we are developing for broad spectrum influenza prophylaxis. CD388 combines a novel multivalent presentation of zanamivir, the antiviral small molecule that is the active ingredient of an FDA-approved drug, with a human antibody fragment to prolong half-life. As a broad-spectrum antiviral that is not dependent on the host immune response for activity, it has the potential to overcome key limitations of existing vaccines. Its unique properties substantially enhance its antiviral activity, making it a potential best-in-class neuraminidase inhibitor. We believe it has the potential to provide universal protection against all influenza A and B virus strains, including high pathogenicity strains like H5N1, also known as avian influenza or bird flu, with potential for single dose per flu season protection.

We discovered and advanced CD388 to the clinic under a license and collaboration agreement, or the Janssen Collaboration Agreement, that we entered in March 2021 with J&J Innovative Medicine, previously Janssen Pharmaceuticals, Inc., one of the Janssen Pharmaceutical Companies of Johnson & Johnson, or Janssen. In 2023, as part of a prioritization of its research and development, or R&D, business, Janssen disclosed its intention to discontinue internal development of multiple product candidates in its infectious disease pipeline, including CD388. Janssen subsequently conducted a competitive divestiture process of its infectious disease portfolio in which we participated and subsequently reacquired all rights to develop and commercialize CD388 in April 2024. Under the terms of a license and technology transfer agreement we entered into with Janssen in April 2024, or the Janssen License Agreement, we received an exclusive, worldwide, fee-bearing but royalty-free license under certain Janssen-controlled technology to develop, manufacture and commercialize CD388 for prophylaxis and treatment of influenza. To date, we have completed two Phase 1 studies and one Phase 2a study of CD388 under the Janssen Collaboration Agreement, and we are currently conducting a 5,041 subject, randomized, double-blind, controlled Phase 2b clinical trial, or the NAVIGATE study, evaluating the efficacy and safety of CD388 for pre-exposure prophylaxis of seasonal influenza. Top-line data from the NAVIGATE study is expected in late June 2025.

Concurrently with the CD388 reacquisition in April 2024, we completed a private placement, which provided $240.0 million in gross proceeds, of which we used $85.0 million to fund the upfront payment under the Janssen License Agreement. The remainder of the gross proceeds of $155.0 million, together with gross proceeds of $105.0 million from a private placement we completed in November 2024, are being utilized to fund the ongoing development of CD388.

In addition, in April 2024 we simultaneously divested rezafungin, our sole non-Cloudbreak asset, to enable us to focus our resources on the development of CD388. We entered into an asset purchase agreement with Napp

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Pharmaceutical Group Limited, or Napp, an affiliate of Mundipharma Medical Company, our licensee for the asset in all territories other than the United States, or U.S., and Japan, pursuant to which we sold to Napp all of our rezafungin assets, including our right to receive future milestones and royalties.

Following these transactions, our sole R&D focus has now shifted to developing CD388 as a highly potent antiviral designed to deliver universal prophylaxis and treatment of seasonal and pandemic influenza.

Risks Associated with our Business

Our business is subject to numerous risks and uncertainties, including those highlighted in the section titled “Risk Factors” immediately following this prospectus summary and those described under similar headings in the documents incorporated by reference into this prospectus. These risks include:

• We need substantial additional funding to advance CD388 beyond Phase 2b, and to advance CBO421 and our other Cloudbreak programs.

• We depend heavily on the success of CD388, which has completed Phase 2a clinical development, and we are very early in our efforts to develop other product candidates from our Cloudbreak program, none of which may be successful.

• If clinical trials for CD388 or any other product candidates are delayed, terminated or suspended, or fail to demonstrate safety and efficacy to the satisfaction of regulatory authorities, we may incur additional costs, or experience delays in completing, or ultimately be unable to complete, the development and commercialization of our product candidates.

• If serious adverse reactions or unexpected characteristics of our product candidates are identified during development, we may need to abandon or limit our development of some or all of our product candidates.

• Any of our product candidates that receive marketing approval may fail to achieve the degree of market acceptance by physicians, patients, formulary committees, third-party payors and others in the medical community necessary for commercial success.

• Interim, topline and preliminary data from our clinical trials that we announce or publish from time to time may change as more patient data become available and are subject to audit and verification procedures that could result in material changes in the final data.

• We intend to continue to rely on third parties to conduct our clinical trials and to conduct some aspects of our research and preclinical testing and those third parties may not perform satisfactorily, including failing to meet deadlines for the completion of such trials, research or testing.

• We have no experience manufacturing product candidates on a clinical or commercial scale and we are dependent on third parties for the manufacture of our product candidates. If we experience problems with any of these third parties, they could delay clinical development or marketing approval of our product candidates or our ability to sell any approved products.

• If we are not able to obtain, or if there are delays in obtaining, required regulatory approvals, we will not be able to commercialize, or will be delayed in commercializing, our product candidates and our ability to generate revenue will be impaired.

• If we are unable to generate revenues from partnerships, government funding or other sources of funding, we may be unable to resume our preclinical Cloudbreak programs.

• The price of our stock may be volatile, and you could lose all or part of your investment.

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Corporate Information

We were incorporated in Delaware as K2 Therapeutics, Inc. in December 2012. In July 2014, we changed our name to Cidara Therapeutics, Inc. Our principal executive offices are located at 6310 Nancy Ridge Drive, Suite 101, San Diego, California 92121, and our telephone number is (858) 752-6170.

We formed wholly-owned subsidiaries, Cidara Therapeutics UK Limited, in England, and Cidara Therapeutics (Ireland) Limited, in Ireland, in March 2016 and October 2018, respectively, for the purpose of developing our product candidates in Europe. Our internet website address is www.cidara.com. We do not incorporate the information on or accessible through our website into this prospectus. The information contained on, or that can be accessed through, our website is not a part of this prospectus. We have included our website address in this prospectus solely as an inactive textual reference.

All brand names or trademarks appearing in this prospectus are the property of their respective holders. Use or display by us of other parties’ trademarks, trade dress, or products in this prospectus is not intended to, and does not, imply a relationship with, or endorsements or sponsorship of, us by the trademark or trade dress owners.

Implications of Being a Smaller Reporting Company

We are a “smaller reporting company” as defined in Item 10(f)(1) of Regulation S-K. Smaller reporting companies may take advantage of certain reduced disclosure obligations, including, among other things, providing only two years of audited financial statements and reduced disclosure obligations regarding executive compensation. We will be a smaller reporting company and may continue to take advantage of the scaled-back disclosures available to smaller reporting companies for so long as (i) the market value of our common stock held by non-affiliates is less than $250.0 million measured on the last business day of our most recently completed second fiscal quarter or (ii) at the time of determination at the end of the fiscal year, (a) our annual revenue is less than $100.0 million during the most recently completed fiscal year for which audited financial statements are then-available and (b) the market value of our common stock held by non-affiliates is less than $700.0 million measured on the last business day of our most recently completed second fiscal quarter. To the extent we take advantage of any reduced disclosure obligations, it may make the comparison of our financial statements with other public companies difficult or impossible.

The Securities We May Offer

We may offer shares of our common stock and preferred stock, various series of debt securities and/or warrants to purchase any of such securities, either individually or in combination, up to a total aggregate offering price of $500,000,000 from time to time in one or more offerings under this prospectus, together with any applicable prospectus supplement and any related free writing prospectus, at prices and on terms to be determined by market conditions at the time of the relevant offering. This prospectus provides you with a general description of the securities we may offer. Each time we offer a type or series of securities under this prospectus, we will provide a prospectus supplement that will describe the specific amounts, prices and other important terms of the securities, including, to the extent applicable:

• designation or classification;

• aggregate principal amount or aggregate offering price;

• maturity;

• original issue discount, if any;

• rates and times of payment of interest or dividends, if any;

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• redemption, conversion, exchange or sinking fund terms, if any;

• conversion or exchange prices or rates, if any, and, if applicable, any provisions for changes to or adjustments in the conversion or exchange prices or rates and in the securities or other property receivable upon conversion or exchange;

• ranking;

• restrictive covenants, if any;

• voting or other rights, if any; and

• important U.S. federal income tax considerations.

The applicable prospectus supplement and any related free writing prospectus that we may authorize to be provided to you may also add, update or change information contained in this prospectus or in documents we have incorporated by reference. However, no prospectus supplement or free writing prospectus will offer a security that is not registered and described in this prospectus at the time of the effectiveness of the registration statement of which this prospectus is a part.

This prospectus may not be used to consummate a sale of securities unless it is accompanied by a prospectus supplement.

We may sell the securities directly to investors or through underwriters, dealers or agents. We, and our underwriters or agents, reserve the right to accept or reject all or part of any proposed purchase of securities. If we do offer securities through underwriters or agents, we will include in the applicable prospectus supplement:

• the names of those underwriters or agents;

• applicable fees, discounts and commissions to be paid to them;

• details regarding options to purchase additional securities granted to the underwriters, if any; and

• the estimated net proceeds to us.

Common Stock. We may issue shares of our common stock from time to time. The holders of our common stock are entitled to one vote for each share held of record on all matters submitted to a vote of stockholders and do not have cumulative voting rights. Subject to preferences that may be applicable to any outstanding shares of preferred stock, the holders of our common stock are entitled to receive ratably such dividends as may be declared by our board of directors out of legally available funds. Upon our liquidation, dissolution or winding up, holders of our common stock are entitled to share ratably in all assets remaining after payment of liabilities and the liquidation preferences of any then outstanding shares of preferred stock. Our common stock does not carry any preemptive rights enabling a holder to subscribe for, or receive shares of, any class of our common stock or any other securities convertible into shares of any class of our common stock, or any redemption rights.

Preferred Stock. We may issue shares of our preferred stock from time to time, in one or more series. Under our amended and restated certificate of incorporation, as amended, our board of directors has the authority, without further action by the stockholders (unless such stockholder action is required by applicable law or the rules of any stock exchange or market on which our securities are then traded), to designate up to 10,000,000 shares of preferred stock in one or more series and to determine the designations, voting powers, preferences and rights of each series of the preferred stock, as well as the qualifications, limitations or restrictions thereof, including dividend rights, conversion rights, preemptive rights, terms of redemption or repurchase, liquidation preferences, sinking fund terms and the number of shares constituting any series or the designation of any series, any or all of which may be greater than the rights of the common stock. Any convertible preferred stock we may issue will be convertible into our common stock or exchangeable for our other securities. Conversion may be mandatory or at the holder’s option and would be at prescribed conversion rates.

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If we sell any series of preferred stock under this prospectus, we will fix the designations, voting powers, preferences and rights of such series of preferred stock, as well as the qualifications, limitations or restrictions thereof, in the certificate of designation relating to that series. We will file as an exhibit to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of any certificate of designation that describes the terms of the series of preferred stock that we are offering before the issuance of the related series of preferred stock. We urge you to read the applicable prospectus supplement (and any free writing prospectus that we may authorize to be provided to you) related to the series of preferred stock being offered, as well as the complete certificate of designation that contains the terms of the applicable series of preferred stock.

Debt Securities. We may issue debt securities from time to time, in one or more series, as either senior or subordinated debt or as senior or subordinated convertible debt. The senior debt securities will rank equally with any other unsecured and unsubordinated debt. The subordinated debt securities will be subordinate and junior in right of payment, to the extent and in the manner described in the instrument governing the debt, to all of our senior indebtedness. Convertible debt securities will be convertible into or exchangeable for our common stock or other securities. Conversion may be mandatory or at the holder’s option and would be at prescribed conversion rates.

The debt securities issued under this prospectus will be issued under one or more documents called indentures, which are contracts between us and a national banking association or other eligible party, as trustee. In this prospectus, we have summarized certain general features of the debt securities. We urge you, however, to read the applicable prospectus supplement (and any free writing prospectus that we may authorize to be provided to you) related to the series of debt securities being offered, as well as the complete indentures that contain the terms of the debt securities. A form of indenture has been filed as an exhibit to the registration statement of which this prospectus is a part, and supplemental indentures and forms of debt securities containing the terms of the debt securities being offered will be filed as exhibits to the registration statement of which this prospectus is a part or will be incorporated by reference from reports that we file with the SEC.

Warrants. We may issue warrants for the purchase of common stock, preferred stock and/or debt securities in one or more series. We may issue warrants independently or together with common stock, preferred stock and/or debt securities, and the warrants may be attached to or separate from these securities. In this prospectus, we have summarized certain general features of the warrants. We urge you, however, to read the applicable prospectus supplement (and any free writing prospectus that we may authorize to be provided to you) related to the particular series of warrants being offered, as well as the complete warrant agreements and warrant certificates that contain the terms of the warrants. Forms of the warrant agreements and forms of warrant certificates containing the terms of the warrants being offered have been filed as exhibits to the registration statement of which this prospectus is a part, and supplemental warrant agreements and forms of warrant certificates will be filed as exhibits to the registration statement of which this prospectus is a part or will be incorporated by reference from reports that we file with the SEC.

We will evidence each series of warrants by warrant certificates that we will issue. Warrants may be issued under an applicable warrant agreement that we enter into with a warrant agent. We will indicate the name and address of the warrant agent, if applicable, in the prospectus supplement relating to the particular series of warrants being offered.

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RISK FACTORS

Investing in our securities involves a high degree of risk. You should carefully review the risks and uncertainties described under the heading “Risk Factors” contained in the applicable prospectus supplement and any related free writing prospectus, and under similar headings in our most recent Annual Report on Form 10-K, as updated by our subsequent Quarterly Reports on Form 10-Q and other filings under the Securities Exchange Act of 1934, as amended, or Exchange Act, and other documents that are incorporated by reference into this prospectus, before deciding whether to purchase any of the securities being registered pursuant to the registration statement of which this prospectus is a part. Each of the risk factors described in the documents referenced above could adversely affect our business, operating results and financial condition, as well as adversely affect the value of an investment in our securities, and the occurrence of any of these risks might cause you to lose all or part of your investment. Additional risks not presently known to us or that we currently believe are immaterial may also significantly harm our business operations.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and the documents incorporated by reference herein contain forward-looking statements. These are based on our management’s current beliefs, expectations and assumptions about future events, conditions and results and on information currently available to us. Discussions containing these forward-looking statements may be found, among other places, in the Sections entitled “Business,” “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” contained in the documents incorporated herein.

Any statements in this prospectus, or incorporated herein, about our expectations, beliefs, plans, objectives, assumptions or future events or performance are not historical facts and are forward-looking statements. Within the meaning of Section 27A of the Securities Act of 1933, as amended, or Securities Act, and Section 21E of the Exchange Act, these forward-looking statements include statements regarding:

• our anticipated timing for preclinical development, regulatory submissions, and commencement and completion of clinical trials for CD388 and other development candidates;

• our plans to develop and commercialize our product candidates;

• our ability to fund our working capital requirements;

• our expected clinical trial designs and regulatory pathways for CD388;

• our ability to obtain and maintain regulatory approval of our product candidates and any related restrictions, limitations, and/or warnings in the label of an approved product candidate;

• our ability to successfully commercialize, and our expectations regarding future therapeutic and commercial potential with respect to, our product candidates;

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

• the rate and degree of market acceptance of our products that are approved;

• our ability to develop sales and marketing capabilities, whether alone or with collaborators;

• regulatory developments in the United States and foreign countries;

• the performance of our third-party suppliers and manufacturers;

• the success of competing therapies that are or may become available;

• our expectations for the attributes of our development candidates, including pharmaceutical properties, efficacy, safety and dosing regimens;

• our estimates of our expenses, ongoing losses, future revenue, capital requirements and our needs for or ability to obtain additional financing;

• our ability to obtain and maintain intellectual property protection for our product candidates;

• our ability to use our Cloudbreak platform to identify development candidates, or to expand our Cloudbreak platform to other areas of infective disease and oncology;

• our ability to identify and develop new product candidates;

• our ability to retain and recruit key personnel;

• our financial performance;

• developments and projections relating to our competitors or our industry;

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• the potential impact of broader macroeconomic conditions, including current or future tariffs, pandemics, inflation, bank failures, labor shortages, supply chain disruptions, recession risks and potential disruptions from the ongoing Russia-Ukraine conflict and related sanctions and the Israel-Hamas war; and

• our use of the net proceeds from any offering under this prospectus.

We caution you that the foregoing list may not contain all of the forward-looking statements made in this prospectus and the documents incorporated by reference herein.

In some cases, you can identify forward-looking statements by the words “may,” “might,” “can,” “will,” “to be,” “could,” “would,” “should,” “expect,” “intend,” “plan,” “objective,” “anticipate,” “believe,” “estimate,” “predict,” “project,” “potential,” “likely,” “continue” and “ongoing,” or the negative of these terms, or other comparable terminology intended to identify statements about the future, although not all forward-looking statements contain these words. These statements involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to be materially different from the information expressed or implied by these forward-looking statements. In addition, statements containing the words “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date of the document in which they are included, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all relevant information. These statements are inherently uncertain and investors are cautioned not to unduly rely upon these statements.

You should refer to the “Risk Factors” section contained in the applicable prospectus supplement and any related free writing prospectus, and under similar headings in the other documents that are incorporated by reference into this prospectus, for a discussion of important factors that may cause our actual results to differ materially from those expressed or implied by our forward-looking statements. Given these risks, uncertainties and other factors, many of which are beyond our control, we cannot assure you that the forward-looking statements in this prospectus will prove to be accurate, and you should not place undue reliance on these forward-looking statements. Furthermore, if our forward-looking statements prove to be inaccurate, the inaccuracy may be material. In light of the significant uncertainties in these forward-looking statements, you should not regard these statements as a representation or warranty by us or any other person that we will achieve our objectives and plans in any specified time frame, or at all.

Except as required by law, we assume no obligation to update these forward-looking statements publicly, or to revise any forward-looking statements to reflect events or developments occurring after the date of this prospectus, even if new information becomes available in the future.

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USE OF PROCEEDS

We will retain broad discretion over the use of the net proceeds from the sale of the securities offered hereby. Except as described in any applicable prospectus supplement or in any free writing prospectuses that we may authorize to be provided to you in connection with a specific offering, we currently intend to use the net proceeds from the sale of the securities offered hereby, if any, primarily to fund the continued research and development of the product candidates in our pipeline, and for working capital, capital expenditures and general corporate purposes. We may also use a portion of the net proceeds to invest in or acquire businesses, products or technologies that we believe are complementary to our own, although we have no current plans, commitments or agreements with respect to any acquisitions as of the date of this prospectus. We will set forth in the applicable prospectus supplement or free writing prospectus our intended use for the net proceeds received from the sale of any securities sold pursuant to the prospectus supplement or free writing prospectus. Pending these uses, we plan to invest these net proceeds in short-term, investment-grade, interest-bearing securities or hold them as cash.

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DESCRIPTION OF CAPITAL STOCK

The following descriptions of our capital stock and provisions of our amended and restated certificate of incorporation, as amended, and amended and restated bylaws and certain provisions of Delaware law are summaries. You should also refer to the amended and restated certificate of incorporation, as amended, and the amended and restated bylaws, which are filed as exhibits to the registration statement of which this prospectus is a part.

General

The following summary description of our capital stock is based on the material provisions of our amended and restated certificate of incorporation, as amended, and amended and restated bylaws, and the applicable provisions of the General Corporation Law of the State of Delaware, or DGCL. This information may not be complete in all respects and is qualified entirely by reference to the provisions of our amended and restated certificate of incorporation, as amended, and amended and restated bylaws, and the DGCL. For information on how to obtain copies of our amended and restated certificate of incorporation, as amended, and amended and restated bylaws, which are exhibits to the registration statement of which this prospectus is a part, see the section entitled “Where You Can Find More Information.”

As of the date of this prospectus, our authorized capital stock consists of 50,000,000 shares of common stock, $0.0001 par value per share, and 10,000,000 shares of preferred stock, $0.0001 par value per share, or Preferred Stock, of which 199,138 shares have been designated as Series A Convertible Voting Preferred Stock, $0.0001 par value per share, or Series A Preferred Stock, and 3,818,495 shares have been designated as Series X Convertible Preferred Stock, $0.0001 par value per share, or Series X Preferred Stock.

Voting Rights. Our common stock is entitled to one vote for each share held of record on all matters submitted to a vote of the stockholders, including the election of directors, and does not have cumulative voting rights. Accordingly, the holders of a majority of the shares of our common stock entitled to vote in any election of directors can elect all of the directors standing for election. For most other matters, the approval of a majority of the shares voting at an annual or special meeting of stockholders will be required. Exceptions to this include removing directors for cause and amending our amended and restated certificate of incorporation, as amended, and amended and restated bylaws, each of which will require the approval of the holders of at least 66 2/3% of the voting power of all of our then outstanding common stock.

Dividends and Distributions. Subject to preferences that may be applicable to any then outstanding Preferred Stock, the holders of outstanding shares of common stock may receive dividends, if any, as may be declared from time to time by the board of directors out of legally available funds. We have never issued a dividend on shares of our common stock, and have no intention to do so in the future.

Liquidation, Dissolution or Winding Up. In the event of our liquidation, dissolution or winding up, the assets legally available for distribution shall be distributed ratably to the holders of shares of common stock and Preferred Stock, subject to the satisfaction of any liquidation preference granted to the holders of any outstanding shares of Preferred Stock.

Other Rights and Preferences. Holders of common stock have no preemptive, conversion or subscription rights, and there are no redemption or sinking fund provisions applicable to the common stock. The rights, preferences and privileges of the holders of common stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of Preferred Stock that our board of directors may designate and issue in the future.

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Preferred Stock

General Description

Our board of directors is authorized, subject to limitations prescribed by Delaware law, to issue up to 10,000,000 shares of Preferred Stock in one or more series, to establish from time to time the number of shares to be included in each series and to fix the designation, powers, preferences and rights of the shares of each series and any of its qualifications, limitations or restrictions. Our board of directors can also increase or decrease the number of shares of any series, but not below the number of shares of that series then outstanding, without any further vote or action by our stockholders. Our board of directors may authorize the issuance of Preferred Stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of the common stock. The issuance of Preferred Stock, while providing flexibility in connection with possible acquisitions and other corporate purposes, could, among other things, have the effect of delaying, deferring, discouraging or preventing a change in control of us and may adversely affect the market price of our common stock and the voting and other rights of the holders of common stock.

Series X Convertible Preferred Stock

Our Certificate of Designation of Preferences, Rights and Limitations of Series X Convertible Preferred Stock, or Series X Certificate of Designation, established the rights, preferences and privileges of the Series X Preferred Stock, which are summarized below.

Conversion. Each share of Series X Preferred Stock is convertible at the option of the holder into 0.5 shares of common stock; provided that holders are not permitted to convert Series X Preferred Stock into common stock if, after conversion, the holder, its affiliates, and any other person whose beneficial ownership of common stock would be aggregated with the holder’s for purposes of Section 13(d) or Section 16 of the Exchange Act, would beneficially own more than 9.99% of the number of shares of common stock outstanding immediately after the conversion.

Dividends and Distributions. Holders of Series X Preferred Stock are not entitled to receive any dividends except to the extent that dividends are paid on our common stock. If dividends are paid on shares of common stock, holders of Series X Preferred Stock are entitled to participate in such dividends on an as-converted basis.

Liquidation, Dissolution or Winding Up. Upon the liquidation, dissolution, or winding up of us, each holder of Series X Preferred Stock will participate pari passu with any distribution of proceeds to holders of Series A Preferred Stock and common stock.

Voting Rights. Shares of Series X Preferred Stock will generally have no voting rights, except as required by law and except that the consent of the holders of a majority of the outstanding Series X Preferred Stock will be required to amend the terms of the Series X Preferred Stock, if such action would adversely alter or change the preferences, rights, privileges or powers of, or restrictions provided for the benefit of the Series X Preferred Stock, or to increase or decrease (other than by conversion) the number of authorized shares of Series X Preferred Stock.

The Series X Certificate of Designation and our amended and restated certificate of incorporation, as amended, do not provide for the repurchase or redemption of shares by us.

Series A Convertible Voting Preferred Stock

Our Certificate of Designation of Preferences, Rights and Limitations of Series A Convertible Voting Preferred Stock, or Series A Certificate of Designation, established the rights, preferences and privileges of the Series A Preferred Stock, which are summarized below.

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Conversion. Each share of Series A Preferred Stock is convertible at the option of the holder into 70 shares of common stock; provided that holders are not permitted to convert Series A Preferred Stock into common stock if, after conversion, the holder, its affiliates, and any other person whose beneficial ownership of common stock would be aggregated with the holder’s for purposes of Section 13(d) or Section 16 of the Exchange Act, would beneficially own more than 9.99% of the number of shares of common stock outstanding immediately after the conversion.

Dividends and Distributions. Holders of Series A Preferred Stock are not entitled to receive any dividends except to the extent that dividends are paid on our common stock. If dividends are paid on shares of common stock, holders of Series A Preferred Stock are entitled to participate in such dividends on an as-if-converted basis.

Liquidation, Dissolution or Winding Up. Upon the liquidation, dissolution, or winding up of us, each holder of Series A Preferred Stock will participate pari passu with any distribution of proceeds to holders of Series X Preferred Stock and common stock.

Voting Rights. Holders of Series A Preferred Stock are entitled to vote together with the holders of common stock on an as-if-converted basis on all matters submitted to a vote of stockholders.

The Series A Certificate of Designation and our amended and restated certificate of incorporation, as amended, do not provide for the repurchase or redemption of shares by us.

Anti-takeover effects of provisions of our certificate of incorporation and bylaws and Delaware law

Certificate of Incorporation and Bylaws

Provisions of our amended and restated certificate of incorporation, as amended, and amended and restated bylaws may delay or discourage transactions involving an actual or potential change in our control or change in our management, including transactions in which stockholders might otherwise receive a premium for their shares or transactions that our stockholders might otherwise deem to be in their best interests. Therefore, these provisions could adversely affect the price of our common stock. Among other things, our amended and restated certificate of incorporation, as amended, and amended and restated bylaws:

• permit our board of directors to issue up to 10,000,000 shares of Preferred Stock, with any rights, preferences and privileges as they may designate;

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

• provide that the board of directors or any individual director may only be removed with cause and the affirmative vote of the holders of at least 66 2/3% of the voting power of all of our then outstanding common stock;

• provide that all vacancies, including newly created directorships, may, except as otherwise required by law or subject to the rights of holders of Preferred Stock as designated from time to time, be filled by the affirmative vote of a majority of directors then in office, even if less than a quorum;

• divide our board of directors into three classes;

• require that any action to be taken by our stockholders must be effected at a duly called annual or special meeting of stockholders and not be taken by written consent or electronic transmission;

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

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

• provide that special meetings of our stockholders may be called only by the chairman of the board, our Chief Executive Officer or by the board of directors pursuant to a resolution adopted by a majority of the total number of authorized directors (whether or not there exists any vacancies); and

• provide that the Court of Chancery of the State of Delaware will be the sole and exclusive forum for (i) any derivative action or proceeding brought on our behalf, (ii) any action asserting a claim of breach of a fiduciary duty owed by any of our directors or officers to us or our stockholders, (iii) any action asserting a claim against us arising pursuant to any provision of the DGCL or our amended and restated certificate of incorporation, as amended, or amended and restated bylaws, or (iv) any action asserting a claim against us governed by the internal affairs doctrine.

Delaware Anti-Takeover Law

We are subject to Section 203 of the DGCL, or Section 203. Section 203 generally prohibits a public Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a period of three years after the date of the transaction in which the person became an interested stockholder, unless:

• prior to the date of the transaction, the board of directors of the corporation approved either the business combination or the transaction which resulted in the stockholder becoming an interested stockholder;

• the interested stockholder owned at least 85% of the voting stock of the corporation outstanding upon consummation of the transaction, excluding for purposes of determining the number of shares outstanding (a) shares owned by persons who are directors and also officers and (b) shares owned by employee stock plans in which employee participants do not have the right to determine confidentially whether shares held subject to the plan will be tendered in a tender or exchange offer; or

• on or subsequent to the consummation of the transaction, the business combination is approved by the board and authorized at an annual or special meeting of stockholders, and not by written consent, by the affirmative vote of at least 66 2/3% of the outstanding voting stock which is not owned by the interested stockholder.

Section 203 defines a business combination to include:

• any merger or consolidation involving the corporation and the interested stockholder;

• any sale, transfer, pledge or other disposition involving the interested stockholder of 10% or more of the assets of the corporation;

• subject to exceptions, any transaction involving the corporation that has the effect of increasing the proportionate share of the stock of any class or series of the corporation beneficially owned by the interested stockholder;

• subject to exceptions, any transaction that results in the issuance or transfer by the corporation of any stock of the corporation to the interested stockholder; and

• the receipt by the interested stockholder of the benefit of any loans, advances, guarantees, pledges or other financial benefits provided by or through the corporation.

In general, Section 203 defines an interested stockholder as any entity or person beneficially owning 15% or more of the outstanding voting stock of the corporation and any entity or person affiliated with or controlling or controlled by the entity or person.

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Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Equiniti Trust Company, LLC (f/k/a American Stock Transfer & Trust Company, LLC). The transfer agent’s address is 55 Challenger Road, Ridgefield Park, New Jersey 07660. The transfer agent for any series of preferred stock that we may offer under this prospectus will be named and described in the prospectus supplement for that series.

Listing on The Nasdaq Capital Market

Our common stock is listed on The Nasdaq Capital Market under the symbol “CDTX.”

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DESCRIPTION OF DEBT SECURITIES

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

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

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

General

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

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

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

• the title of the series of debt securities;

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

• the maturity date or dates;

• the form of the debt securities of the series;

• the applicability of any guarantees;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Conversion or Exchange Rights

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

Consolidation, Merger or Sale

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

Events of Default under the Indenture

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Modification of Indenture; Waiver

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Discharge

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

• provide for payment;

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

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

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

• maintain paying agencies;

• hold monies for payment in trust;

• recover excess money held by the trustee;

• compensate and indemnify the trustee; and

• appoint any successor trustee.

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

Form, Exchange and Transfer

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

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

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

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

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

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

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

Information Concerning the Trustee

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

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Payment and Paying Agents

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

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

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

Governing Law

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

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DESCRIPTION OF WARRANTS

The following description, together with the additional information we may include in any applicable prospectus supplements and in any related free writing prospectuses, summarizes the material terms and provisions of the warrants that we may offer under this prospectus, which may consist of warrants to purchase common stock, preferred stock or debt securities and may be issued in one or more series. Warrants may be offered and issued independently or together with common stock, preferred stock or debt securities offered by any prospectus supplement, and may be attached to or separate from those securities. While the terms we have summarized below will apply generally to any warrants that we may offer under this prospectus, we will describe the particular terms of any series of warrants that we may offer in more detail in the applicable prospectus supplement and any applicable free writing prospectus. The terms of any warrants offered under a prospectus supplement may differ from the terms described below. However, no prospectus supplement will fundamentally change the terms that are set forth in this prospectus or offer a security that is not registered and described in this prospectus at the time of its effectiveness.

We have filed forms of the warrant agreements and forms of warrant certificates containing the terms of the warrants that may be offered as exhibits to the registration statement of which this prospectus is a part. We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of warrant agreement, if any, including a form of warrant certificate, that describes the terms of the particular series of warrants we are offering. The following summaries of material provisions of the warrants and the warrant agreements are subject to, and qualified in their entirety by reference to, all the provisions of the warrant agreement and warrant certificate applicable to the particular series of warrants that we may offer under this prospectus. We urge you to read the applicable prospectus supplements related to the particular series of warrants that we may offer under this prospectus, as well as any related free writing prospectuses, and the complete warrant agreements and warrant certificates that contain the terms of the warrants.

General

We will describe in the applicable prospectus supplement the terms relating to a series of warrants being offered, including, to the extent applicable:

• the title of such securities;

• the offering price or prices and aggregate number of warrants offered;

• the currency or currencies for which the warrants may be purchased;

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

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

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

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

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

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

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

• the terms of any rights to force the exercise of the warrants;

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

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

• the manner in which the warrant agreements and warrants may be modified;

• a discussion of any material or special U.S. federal income tax consequences of holding or exercising the warrants;

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

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

Before exercising their warrants, holders of warrants will not have any of the rights of holders of the securities purchasable upon such exercise, including:

• in the case of warrants to purchase debt securities, the right to receive payments of principal of, or premium, if any, or interest on, the debt securities purchasable upon exercise or to enforce covenants in the applicable indenture; or

• in the case of warrants to purchase common stock or preferred stock, the right to receive dividends, if any, or, payments upon our liquidation, dissolution or winding up or to exercise voting rights, if any.

Exercise of Warrants

Each warrant will entitle the holder to purchase the securities that we specify in the applicable prospectus supplement at the exercise price that we describe in the applicable prospectus supplement. Unless we otherwise specify in the applicable prospectus supplement, holders of the warrants may exercise the warrants at any time up to the specified time on the expiration date that we set forth in the applicable prospectus supplement. After the close of business on the expiration date, unexercised warrants will become void.

Unless we otherwise specify in the applicable prospectus supplement, holders of the warrants may exercise the warrants by delivering the warrant certificate representing the warrants to be exercised together with specified information, and paying the required amount to the warrant agent in immediately available funds, as provided in the applicable prospectus supplement. We will set forth on the reverse side of the warrant certificate and in the applicable prospectus supplement the information that the holder of the warrant will be required to deliver to the warrant agent in connection with the exercise of the warrant.

Upon receipt of the required payment and the warrant certificate properly completed and duly executed at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement, we will issue and deliver the securities purchasable upon such exercise. If fewer than all of the warrants represented by the warrant certificate are exercised, then we will issue a new warrant certificate for the remaining amount of warrants. If we so indicate in the applicable prospectus supplement, holders of the warrants may surrender securities as all or part of the exercise price for warrants.

Governing Law

Unless we provide otherwise in the applicable prospectus supplement, the warrants and warrant agreements, and any claim, controversy or dispute arising under or related to the warrants or warrant agreements, will be governed by and construed in accordance with the laws of the State of New York.

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Enforceability of Rights by Holders of Warrants

Each warrant agent will act solely as our agent under the applicable warrant agreement and will not assume any obligation or relationship of agency or trust with any holder of any warrant. A single bank or trust company may act as warrant agent for more than one issue of warrants. A warrant agent will have no duty or responsibility in case of any default by us under the applicable warrant agreement or warrant, including any duty or responsibility to initiate any proceedings at law or otherwise, or to make any demand upon us. Any holder of a warrant may, without the consent of the related warrant agent or the holder of any other warrant, enforce by appropriate legal action its right to exercise, and receive the securities purchasable upon exercise of, its warrants.

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LEGAL OWNERSHIP OF SECURITIES

We can issue securities in registered form or in the form of one or more global securities. We describe global securities in greater detail below. We refer to those persons who have securities registered in their own names on the books that we or any applicable trustee, depositary or warrant agent maintain for this purpose as the “holders” of those securities. These persons are the legal holders of the securities. We refer to those persons who, indirectly through others, own beneficial interests in securities that are not registered in their own names, as “indirect holders” of those securities. As we discuss below, indirect holders are not legal holders, and investors in securities issued in book-entry form or in street name will be indirect holders.

Book-Entry Holders

We may issue securities in book-entry form only, as we will specify in the applicable prospectus supplement. This means securities may be represented by one or more global securities registered in the name of a financial institution that holds them as depositary on behalf of other financial institutions that participate in the depositary’s book-entry system. These participating institutions, which are referred to as participants, in turn, hold beneficial interests in the securities on behalf of themselves or their customers.

Only the person in whose name a security is registered is recognized as the holder of that security. Global securities will be registered in the name of the depositary or its participants. Consequently, for global securities, we will recognize only the depositary as the holder of the securities, and we will make all payments on the securities to the depositary. The depositary passes along the payments it receives to its participants, which in turn pass the payments along to their customers who are the beneficial owners. The depositary and its participants do so under agreements they have made with one another or with their customers; they are not obligated to do so under the terms of the securities.

As a result, investors in a global security will not own securities directly. Instead, they will own beneficial interests in a global security, through a bank, broker or other financial institution that participates in the depositary’s book-entry system or holds an interest through a participant. As long as the securities are issued in global form, investors will be indirect holders, and not legal holders, of the securities.

Street Name Holders

We may terminate a global security or issue securities that are not issued in global form. In these cases, investors may choose to hold their securities in their own names or in “street name.” Securities held by an investor in street name would be registered in the name of a bank, broker or other financial institution that the investor chooses, and the investor would hold only a beneficial interest in those securities through an account he or she maintains at that institution.

For securities held in street name, we or any applicable trustee or depositary will recognize only the intermediary banks, brokers and other financial institutions in whose names the securities are registered as the holders of those securities, and we or any such trustee or depositary will make all payments on those securities to them. These institutions pass along the payments they receive to their customers who are the beneficial owners, but only because they agree to do so in their customer agreements or because they are legally required to do so. Investors who hold securities in street name will be indirect holders, not legal holders, of those securities.

Legal Holders

Our obligations, as well as the obligations of any applicable trustee or third party employed by us or a trustee, run only to the legal holders of the securities. We do not have obligations to investors who hold beneficial interests in global securities, in street name or by any other indirect means. This will be the case whether an investor chooses to be an indirect holder of a security or has no choice because we are issuing the securities only in global form.

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For example, once we make a payment or give a notice to the holder, we have no further responsibility for the payment or notice even if that holder is required, under agreements with its participants or customers or by law, to pass it along to the indirect holders but does not do so. Similarly, we may want to obtain the approval of the holders to amend an indenture, to relieve us of the consequences of a default or of our obligation to comply with a particular provision of an indenture, or for other purposes. In such an event, we would seek approval only from the holders, and not the indirect holders, of the securities. Whether and how the legal holders contact the indirect holders is up to the legal holders.

Special Considerations for Indirect Holders

If you hold securities through a bank, broker or other financial institution, either in book-entry form because the securities are represented by one or more global securities or in street name, you should check with your own institution to find out:

• how it handles securities payments and notices;

• whether it imposes fees or charges;

• how it would handle a request for the holders’ consent, if ever required;

• whether and how you can instruct it to send you securities registered in your own name so you can be a holder, if that is permitted in the future;

• how it would exercise rights under the securities if there were a default or other event triggering the need for holders to act to protect their interests; and

• if the securities are in book-entry form, how the depositary’s rules and procedures will affect these matters.

Global Securities

A global security is a security that represents one or any other number of individual securities held by a depositary. Generally, all securities represented by the same global securities will have the same terms.

Each security issued in book-entry form will be represented by a global security that we issue to, deposit with and register in the name of a financial institution or its nominee that we select. The financial institution that we select for this purpose is called the depositary. Unless we specify otherwise in the applicable prospectus supplement, The Depository Trust Company, New York, New York, known as DTC, will be the depositary for all securities issued in book-entry form.

A global security may not be transferred to or registered in the name of anyone other than the depositary, its nominee or a successor depositary, unless special termination situations arise. We describe those situations below under “—Special Situations When a Global Security Will Be Terminated.” As a result of these arrangements, the depositary, or its nominee, will be the sole registered owner and legal holder of all securities represented by a global security, and investors will be permitted to own only beneficial interests in a global security. Beneficial interests must be held by means of an account with a broker, bank or other financial institution that in turn has an account with the depositary or with another institution that does. Thus, an investor whose security is represented by a global security will not be a legal holder of the security, but only an indirect holder of a beneficial interest in the global security.

If the prospectus supplement for a particular security indicates that the security will be issued as a global security, then the security will be represented by a global security at all times unless and until the global security is terminated. If termination occurs, we may issue the securities through another book-entry clearing system or decide that the securities may no longer be held through any book-entry clearing system.

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Special Considerations for Global Securities

As an indirect holder, an investor’s rights relating to a global security will be governed by the account rules of the investor’s financial institution and of the depositary, as well as general laws relating to securities transfers. We do not recognize an indirect holder as a holder of securities and instead deal only with the depositary that holds the global security.

If securities are issued only as global securities, an investor should be aware of the following:

• an investor cannot cause the securities to be registered in his or her name, and cannot obtain non-global certificates for his or her interest in the securities, except in the special situations we describe below;

• an investor will be an indirect holder and must look to his or her own bank or broker for payments on the securities and protection of his or her legal rights relating to the securities, as we describe above;

• an investor may not be able to sell interests in the securities to some insurance companies and to other institutions that are required by law to own their securities in non-book-entry form;

• an investor may not be able to pledge his or her interest in the global security in circumstances where certificates representing the securities must be delivered to the lender or other beneficiary of the pledge in order for the pledge to be effective;

• the depositary’s policies, which may change from time to time, will govern payments, transfers, exchanges and other matters relating to an investor’s interest in the global security;

• we and any applicable trustee have no responsibility for any aspect of the depositary’s actions or for its records of ownership interests in the global security, nor will we or any applicable trustee supervise the depositary in any way;

• the depositary may, and we understand that DTC will, require that those who purchase and sell interests in the global security within its book-entry system use immediately available funds, and your broker or bank may require you to do so as well; and

• financial institutions that participate in the depositary’s book-entry system, and through which an investor holds its interest in the global security, may also have their own policies affecting payments, notices and other matters relating to the securities.

There may be more than one financial intermediary in the chain of ownership for an investor. We do not monitor and are not responsible for the actions of any of those intermediaries.

Special Situations When a Global Security Will Be Terminated

In a few special situations described below, a global security will terminate and interests in it will be exchanged for physical certificates representing those interests. After that exchange, the choice of whether to hold securities directly or in street name will be up to the investor. Investors must consult their own banks or brokers to find out how to have their interests in securities transferred to their own names, so that they will be direct holders. We have described the rights of holders and street name investors above.

Unless we provide otherwise in the applicable prospectus supplement, a global security will terminate when the following special situations occur:

• if the depositary notifies us that it is unwilling, unable or no longer qualified to continue as depositary for that global security and we do not appoint another institution to act as depositary within 90 days;

• if we notify any applicable trustee that we wish to terminate that global security; or

• if an event of default has occurred with regard to securities represented by that global security and has not been cured or waived.

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The applicable prospectus supplement may also list additional situations for terminating a global security that would apply only to the particular series of securities covered by the prospectus supplement. When a global security terminates, the depositary, and neither we nor any applicable trustee, is responsible for deciding the names of the institutions that will be the initial direct holders.

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PLAN OF DISTRIBUTION

We may sell the securities from time to time pursuant to underwritten public offerings, negotiated transactions, block trades or a combination of these methods. We may sell the securities to or through underwriters or dealers, through agents, or directly to one or more purchasers. We may distribute securities from time to time in one or more transactions:

• at a fixed price or prices, which may be changed;

• at market prices prevailing at the time of sale;

• at prices related to such prevailing market prices; or

• at negotiated prices.

We may also sell equity securities covered by this registration statement in an “at the market offering” as defined in Rule 415(a)(4) under the Securities Act. Such offering may be made into an existing trading market for such securities in transactions at other than a fixed price on or through the facilities of The Nasdaq Capital Market or any other securities exchange or quotation or trading service on which such securities may be listed, quoted or traded at the time of sale.

Such at the market offerings, if any, may be conducted by underwriters acting as principal or agent.

A prospectus supplement or supplements (and any related free writing prospectus that we may authorize to be provided to you) will describe the terms of the offering of the securities, including, to the extent applicable:

• the name or names of any underwriters, dealers or agents, if any;

• the purchase price of the securities and the proceeds we will receive from the sale;

• any options to purchase additional securities granted to the underwriters;

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

• any public offering price;

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

• any securities exchange or market on which the securities may be listed.

Only underwriters named in the prospectus supplement are underwriters of the securities offered by the prospectus supplement.

If underwriters are used in the sale, they will acquire the securities for their own account and may resell the securities from time to time in one or more transactions at a fixed public offering price or at varying prices determined at the time of sale. The obligations of the underwriters to purchase the securities will be subject to the conditions set forth in the applicable underwriting agreement. We may offer the securities to the public through underwriting syndicates represented by managing underwriters or by underwriters without a syndicate. Subject to certain conditions, the underwriters will be obligated to purchase all of the securities offered by the prospectus supplement, other than securities covered by any overallotment or other option. Any public offering price and any discounts or concessions allowed or reallowed or paid to dealers may change from time to time. We may use underwriters with whom we have a material relationship. We will describe in the prospectus supplement, naming the underwriter, the nature of any such relationship.

We may sell securities directly or through agents we designate from time to time. We will name any agent involved in the offering and sale of securities, and we will describe any commissions we will pay the agent in the

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prospectus supplement. Unless the prospectus supplement states otherwise, our agent will act on a best-efforts basis for the period of its appointment.

We may authorize agents or underwriters to solicit offers by certain types of institutional investors to purchase securities from us at the public offering price set forth in the prospectus supplement pursuant to delayed delivery contracts providing for payment and delivery on a specified date in the future. We will describe the conditions to these contracts and the commissions we must pay for solicitation of these contracts in the prospectus supplement.

We may provide agents and underwriters with indemnification against civil liabilities related to this offering, including liabilities under the Securities Act, or contribution with respect to payments that the agents or underwriters may make with respect to these liabilities. Agents and underwriters may engage in transactions with, or perform services for, us in the ordinary course of business.

Unless otherwise specified in the related prospectus supplement, all securities we may offer, other than common stock, will be new issues of securities with no established trading market. Any underwriters may make a market in these securities, but will not be obligated to do so and may discontinue any market making at any time without notice. We cannot guarantee the liquidity of the trading markets for any securities.

Any underwriter may engage in overallotment, stabilizing transactions, short covering transactions and penalty bids. 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 stabilizing or 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. These transactions may be effected on any exchange or over-the-counter market or otherwise.

Any underwriters or agents who are qualified market makers on The Nasdaq Capital Market may engage in passive market making transactions in the securities on The Nasdaq Capital Market in accordance with Rule 103 of Regulation M under the Exchange Act, during the business day prior to the pricing of the offering, before the commencement of offers or sales of the securities. Passive market makers must comply with applicable volume and price limitations and must be identified as passive market makers. In general, a passive market maker must display its bid at a price not in excess of the highest independent bid for such security; if all independent bids are lowered below the passive market maker’s bid, however, the passive market maker’s bid must then be lowered when certain purchase limits are exceeded. Passive market making may stabilize the market price of the securities at a level above that which might otherwise prevail in the open market and, if commenced, may be discontinued at any time.

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LEGAL MATTERS

Unless otherwise indicated in the applicable prospectus supplement, certain legal matters in connection with the offering and the validity of the securities offered by this prospectus, and any supplement thereto, will be passed upon by Cooley LLP, San Diego, California. Additional legal matters may be passed upon for us or any underwriters, dealers or agents, by counsel that we will name in the applicable prospectus supplement.

EXPERTS

Ernst & Young LLP, independent registered public accounting firm, has audited our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2024, as set forth in their report, which is incorporated by reference into this prospectus and elsewhere in the registration statement. Our financial statements are incorporated by reference in reliance on Ernst & Young LLP’s report, given on their authority as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

This prospectus is part of a registration statement on Form S-3 we filed with the SEC under the Securities Act and does not contain all the information set forth or incorporated by reference in the registration statement. Whenever a reference is made in this prospectus to any of our contracts, agreements or other documents, the reference may not be complete and you should refer to the exhibits that are a part of the registration statement or the exhibits to the reports or other documents incorporated by reference into this prospectus for a copy of such contract, agreement or other document.

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 Cidara. The address of the SEC website is www.sec.gov.

We maintain a website at www.cidara.com. Information contained in or accessible through our website does not constitute a part of this prospectus.

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INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to “incorporate by reference” information into this prospectus, which means that we can disclose important information to you by referring you to another document filed separately with the SEC. The SEC file number for the documents incorporated by reference in this prospectus is 001-36912. The documents incorporated by reference into this prospectus contain important information that you should read about us.

The following documents are incorporated by reference into this document:

• our Annual Report on Form 10-K for the fiscal year ended December 31, 2024, filed with the SEC on March 6, 2025;

• the information specifically incorporated by reference into our Annual Report on Form 10-K for the fiscal year ended December 31, 2024 from our definitive proxy statement on Schedule 14A (other than information furnished rather than filed), filed with the SEC on April 25, 2025;

• our Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2025, filed with the SEC on May 8, 2025;

• our Current Reports on Form 8-K, filed with the SEC on January 7, 2025 and February 18, 2025; and

• the description of our common stock which is contained in our registration statement on Form 8-A filed on April 9, 2015 under the Exchange Act, as updated by the description of our common stock contained as Exhibit 4.5 to our Annual Report on Form 10-K for the fiscal year ended December  31, 2024, filed with the SEC on March 6, 2025, including any amendment or report filed for the purpose of updating such description.

We also incorporate by reference into this prospectus all documents (other than Current Reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items, and other portions of documents that are furnished, but not filed, or are otherwise not incorporated into registration statements pursuant to applicable rules promulgated by the SEC) that are filed by us with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (i) after the date of the initial filing of the registration statement of which this prospectus forms a part and prior to effectiveness of the registration statement, or (ii) after the date of this prospectus but prior to the termination of all offerings covered by this prospectus. These documents include periodic reports, such as Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, as well as proxy statements.

We will provide to each person, including any beneficial owner, to whom a prospectus is delivered, without charge upon written or oral request, a copy of any or all of the documents that are incorporated by reference into this prospectus but not delivered with the prospectus, including exhibits that are specifically incorporated by reference into such documents. You should direct any requests for documents to Cidara Therapeutics, Inc., Attn: Corporate Secretary, 6310 Nancy Ridge Drive, Suite 101, San Diego, California 92121; telephone: (858) 752-6170.

Any statement contained herein or in a document incorporated or deemed to be incorporated by reference into this prospectus will be deemed to be modified or superseded for purposes of the document to the extent that a statement contained in this document or any other subsequently filed document that is deemed to be incorporated by reference into this prospectus modifies or supersedes the statement.

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$250,000,000

Common Stock

Prospectus Supplement

J.P. Morgan Morgan Stanley Guggenheim Securities Cantor

    , 2025