[424B7] Coya Therapeutics, Inc. Prospectus Filed Pursuant to Rule 424(b)(7)

Rhea-AI Filing Summary

Coya Therapeutics focuses on regulatory T cells (Tregs) and is developing low-dose IL-2 (LD IL-2) combination biologics for neurodegenerative disorders. The company describes COYA 302 as a "Pipeline in a Product" and reports nonclinical data showing COYA 303 increased Treg suppressive function by 42% (p < 0.001) versus single agents, and reduced BAX transcript levels (p < 0.01), supporting Treg survival. COYA 301 alone increased Treg suppression 15% and GLP-1RA alone 20% in the same assay. Coya re-submitted an IND on June 30, 2025 to support a planned Phase 2 randomized, double-blind, placebo-controlled 24-week study (with 24-week open-label extension) of COYA 302 in ALS and plans to initiate the study upon IND acceptance. The company reported net losses of $13.4 million and $7.9 million for the six months ended June 30, 2025 and 2024, respectively, and an accumulated deficit of $54.1 million as of June 30, 2025.

Positive

• Strong nonclinical synergy: COYA 303 increased Treg suppressive function by 42% (p < 0.001) versus single agents.
• Mechanistic support: COYA 303 reduced BAX transcript levels (p < 0.01), suggesting enhanced Treg survival via apoptosis modulation.
• Regulatory progress: IND re-submitted on June 30, 2025 to support a planned Phase 2 randomized, double-blind, placebo-controlled 24-week study (with 24-week OLE) of COYA 302 in ALS.

Negative

• Preclinical/early-stage risk: Key efficacy results are nonclinical; clinical safety and efficacy remain unproven.
• Financial burn: Net losses increased to $13.4 million for the six months ended June 30, 2025, from $7.9 million a year earlier, and an accumulated deficit of $54.1 million.
• Financing need: The company will likely require additional capital to fund clinical development; no product revenue is reported.

Insights

Securities Analyst

TL;DR: Positive preclinical synergy and an IND resubmission for a Phase 2 ALS study could be value-relevant if clinical outcomes follow.

Coya presents convincing nonclinical synergy for its combination biologic platform: COYA 303 delivered a 42% increase in Treg suppressive function with strong statistical significance, and reduced apoptotic marker BAX, which supports a mechanism for enhanced Treg survival. The IND resubmission for a Phase 2 ALS trial is a material development that, upon acceptance, would advance a de-risking clinical milestone. However, these are preclinical and early clinical-stage milestones; real value depends on clinical safety, efficacy, and enrollment progress. Financially, rising net losses and an accumulated deficit highlight ongoing dilution and financing needs ahead of potential revenue generation.

Risk Analyst

TL;DR: Scientific signals are encouraging but program risk and cash runway are material near-term concerns.

The reported preclinical efficacy and IND resubmission are positive operational steps, yet the company remains pre-revenue with increasing six-month net losses ($13.4M versus $7.9M prior year) and a $54.1M accumulated deficit. Clinical development, regulatory acceptance, and execution of a multi-center Phase 2 ALS trial carry execution, safety, and enrollment risks. Additional financing is likely required to complete trials. Investors should note the program-stage concentration and typical attrition risk for biologics transitioning from nonclinical to clinical proof-of-concept.

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Filed Pursuant to Rule 424(b)(7)
Registration No. 333-289511

PROSPECTUS

Coya Therapeutics, Inc.

$75,000,000

Common Stock

Preferred Stock

Warrants

Debt Securities

Subscription Rights

Units

We may offer, issue and sell from time to time together or separately, in one or more offerings, any combination of (i) our common stock, (ii) our preferred stock, which we may issue in one or more series, (iii) warrants, (iv) senior or subordinated debt securities, (v) subscription rights and (vi) units. The debt securities may consist of debentures, notes, or other types of debt. The debt securities, preferred stock, warrants and subscription rights may be convertible into, or exercisable or exchangeable for, common or preferred stock or other securities of ours. The units may consist of any combination of the securities listed above.

The aggregate public offering price of the securities that we may offer will not exceed $75,000,000. We will offer the securities in an amount and on terms that market conditions will determine at the time of the offering. Our common stock is listed on The Nasdaq Capital Market under the symbol “COYA.” The last reported sale price for our common stock on August 11, 2025 as quoted on The Nasdaq Capital Market was $6.15 per share. You are urged to obtain current market quotations of our common stock. We have no preferred stock, warrants, debt securities, subscription rights or units listed on any trading market. Each prospectus supplement will indicate if the securities offered thereby will be listed on any securities exchange.

Investing in our securities involves risk. You should carefully consider the risks that we refer you to under the section captioned “Risk Factors” in this prospectus on page 6 before buying our securities.

Should we offer any of the securities described in this prospectus, we will provide you with the specific terms of the particular securities being offered in supplements to this prospectus. You should read this prospectus and any supplement, together with additional information described under the headings “Additional Information” and “Incorporation of Certain Information by Reference” carefully before you invest. This prospectus may not be used to sell securities unless accompanied by a prospectus supplement.

We may sell these securities directly to our stockholders or to other purchasers or through agents on our behalf or through underwriters or dealers as designated from time to time. If any agents or underwriters are involved in the sale of any of these securities, the applicable prospectus supplement will provide the names of the agents or underwriters and any applicable fees, commissions or discounts.

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 August 19, 2025.

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TABLE OF CONTENTS

ABOUT THIS PROSPECTUS			1
PROSPECTUS SUMMARY			2
RISK FACTORS			6
CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS			7
USE OF PROCEEDS			9
THE SECURITIES WE MAY OFFER			10
DESCRIPTION OF CAPITAL STOCK			11
DESCRIPTION OF STOCK WARRANTS			16
DESCRIPTION OF DEBT SECURITIES			18
DESCRIPTION OF SUBSCRIPTION RIGHTS			24
DESCRIPTION OF UNITS			25
FORMS OF SECURITIES			26
PLAN OF DISTRIBUTION			28
LEGAL MATTERS			32
EXPERTS			32
ADDITIONAL INFORMATION			33
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE			34

Coya Therapeutics, Inc. is referred to herein as “Coya,” “the Company,” “we,” “us,” and “our,” unless the context indicates otherwise.

You may only rely on the information contained in or incorporated by reference in this prospectus, and any accompanying prospectus supplement or in any free writing prospectus filed by us with the Securities and Exchange Commission, which we refer to as the “SEC.” We have not authorized anyone to provide you with different information. This prospectus and any prospectus supplement do not constitute an offer to sell or a solicitation of an offer to buy any securities other than the securities offered by this prospectus or such accompanying prospectus supplement. This prospectus and any prospectus supplement do not constitute an offer to sell or a solicitation of an offer to buy any securities in any circumstances in which such offer or solicitation is unlawful. Neither the delivery of this prospectus or any prospectus supplement nor any sale made hereunder shall, under any circumstances, create any implication that there has been no change in our affairs since the date of this prospectus or such prospectus supplement or that the information incorporated by reference to this prospectus or any prospectus supplement is correct as of any time after its date.

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the SEC, using a “shelf” registration process. Under this shelf registration process, we may from time to time offer and sell, in one or more offerings, any or all of the securities described in this prospectus, separately or together, up to an aggregate offering price of $75,000,000. This prospectus provides you with a general description of our securities being offered. When we issue the securities being offered by this prospectus, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement may also add, update or change information contained in this prospectus. You should read both this prospectus and any prospectus supplement together with additional information described under the heading “Additional Information” and “Incorporation of Certain Information by Reference.”

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PROSPECTUS SUMMARY

The following summary highlights some information from this prospectus. It is not complete and does not contain all of the information that you should consider before making an investment decision. You should read this entire prospectus, including the “Risk Factors” section on page 6 and the disclosures to which that section refers you, the financial statements and related notes and the other more detailed information appearing elsewhere, including in any accompanying prospectus supplement, or incorporated by reference into this prospectus before investing in any of the securities described in this prospectus.

Overview

We are a clinical-stage biotechnology company focused on developing proprietary new therapies to enhance the function of regulatory T cells (“Tregs”). Tregs are a subpopulation of T-lymphocytes consisting of CD4+CD25high hFOXP3+ cells that suppress inflammatory responses. Tregs were first discovered in 1995 by Dr. Shimon Sakaguchi and since their discovery multiple lines of research have contributed to elucidate Treg biology and its role in health and disease. Tregs and their transcription factors have been shown to be essential to maintaining cellular homeostasis by regulating autoimmune and inflammatory responses and maintaining self-tolerance in mammals. Dysfunctional Tregs underlie numerous disease states, and this cellular dysfunction is driven by the chronic inflammatory environment and high levels of oxidative stress commonly observed in certain diseases. Further, the degree of Treg dysfunction is correlated with the severity and progression of serious and life-threatening conditions. These and other recent advances in the understanding of Treg biology, have made this subset of T-lymphocytes an important potential therapeutic target, which we believe may provide new treatments for serious diseases.

Our core focus is developing therapies to target Treg dysfunction. Treg disfunction has been identified as an important pathophysiological component of neurodegenerative, autoimmune, and metabolic diseases, all areas where we believe new and effective therapies are urgently needed. We believe we have expertise in three distinct potential therapeutic modalities: Treg-enhancing biologics, Treg-derived exosomes, and autologous Treg cell therapy. Our expertise includes both ex vivo and in vivo approaches intended to restore the suppressive and immunomodulatory functions of Tregs.

Our lead asset, COYA 302, is a Treg-enhancing biologic, which was developed from key learnings established in our early work and discoveries of our autologous Treg cell therapy asset. Our autologous Treg cell therapy program has completed a Phase 1 and Phase 2a studies in amyotrophic lateral sclerosis, or ALS. The clinical data from these initial studies has served as an important confirmation of the underlying immunomodulatory properties of Tregs and their potential therapeutic benefits. These studies have also significantly expanded our own foundational knowledge of the biological activity of Tregs and key biomarkers of disease progression and drug effect, which we believe will be critical for the design of our future clinical and preclinical studies, the selection of future targeted diseases and the overall advancement of our development pipeline. We believe our findings have also established mechanistic benefits of combination biologics to address Treg dysfunction as well as highlighted important advantages of scalability and cost.

COYA 302 is the combination of our proprietary low dose interleukin-2 (COYA 301, or LD IL-2) and the immunomodulatory drug CTLA4-Ig, and we believe this combination has the potential to provide a sustained and durable effect on our first series of indications (neurodegenerative disorders) through targeting of multiple pathways. Our research and clinical efforts have led us to believe that combination biologics using our LD IL-2 as a backbone modality could be an effective way to treat neurodegenerative conditions that are inherently driven by a complexity of pathways. We believe COYA 302 is the most clinically advanced of what we hope will be a family of combination therapies that all feature our LD IL-2. Given the growing list of indications for which we are developing it, we can now refer to COYA 302 as a “Pipeline in a Product.”

Our operations have consisted of developing our clinical and preclinical product candidates and we have devoted substantially all of our resources to developing product and technology rights, conducting research and

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development (which includes preclinical and non-clinical studies of our product candidates), organizing and staffing our company, ongoing business operations and raising capital. We have funded our operations primarily through the private and public sale of our securities. Our net losses were $13.4 million and $7.9 million for the six months ended June 30, 2025 and 2024, respectively. As of June 30, 2025, we had an accumulated deficit of $54.1 million. Our primary use of cash is to fund operating expenses, which consist primarily of research and development expenditures and general and administrative expenditures. Our ability to generate product revenue sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of one or more of our current or future product candidates.

We expect to continue to incur significant expenses and operating losses for the foreseeable future as we advance our product candidates through all stages of development and clinical trials and, ultimately, seek regulatory approval. In addition, if we obtain marketing approval for any of our product candidates, we expect to incur significant commercialization expenses related to product manufacturing, marketing, sales and distribution. We expect our expenses and capital requirements will increase significantly in connection with our ongoing activities as we:

• continue our ongoing and planned research and development of our product candidates;

• initiate nonclinical studies and clinical trials for any additional product candidates that we may pursue;

• continue to scale up external manufacturing capacity with the aim of securing sufficient quantities to meet our capacity requirements for clinical trials and potential commercialization;

• establish a sales, marketing and distribution infrastructure to commercialize any approved product candidates and related additional commercial manufacturing costs;

• develop, maintain, expand, protect and enforce our intellectual property portfolio, including patents, trade secrets and know-how;

• acquire or in-license other product candidates and technologies;

• add clinical, operational, financial and management information systems and personnel, including personnel to support our product development and planned future commercialization efforts; and

• incur additional legal, accounting, investor relations and other expenses associated with operating as a public company.

Our net losses may fluctuate significantly from quarter-to-quarter and year-to-year, depending on the timing of our clinical trials and our expenditures on other research and development activities.

We will need to raise substantial additional capital to support our continuing operations and pursue our growth strategy. Until such time as we can generate significant revenue from product sales, if ever, we plan to finance our operations through the sale of equity, debt financings or other capital sources, which may include collaborations with other companies or other strategic transactions. There are no assurances that we will be successful in obtaining an adequate level of financing as and when needed to finance our operations on terms acceptable to us or at all. Any failure to raise capital as and when needed could have a negative impact on our financial condition and on our ability to pursue our business plans and strategies. If we are unable to secure adequate additional funding, we may have to significantly delay, scale back or discontinue the development and commercialization of one or more product candidates or delay our pursuit of potential in-licenses or acquisitions.

Recent Developments

On January 21, 2025, we announced the expansion of our investigational pipeline with a new product candidate called COYA 303 for the treatment of inflammatory diseases. Sustained inflammatory responses driven by dysfunctional immune regulation is a hallmark of serious autoimmune and neurodegenerative diseases. COYA 303 is an investigational biologic combination of COYA 301 and a glucagon-like-peptide-1 receptor

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agonist designed for subcutaneous administration. In a preclinical study, COYA 303 exhibited a dual immunomodulatory mechanism of action resulting in an additive/synergistic anti-inflammatory effect, which we believe was due to increased Treg function and suppressed pro-inflammatory myeloid cells and responder T cells. We have filed several patents applications to protect this compound.

On April 21, 2025, we published the results of the study first referenced above. The study was designed to evaluate the effects of COYA 303 (LD IL-2 and GLP-1RA), our investigational biologic combination to suppress pro-inflammatory myeloid cells, enhance Treg suppressive function, and modulate T cell proliferation, in an in vitro system of human immune cells obtained from healthy donors. The research was conducted at the Houston Methodist Research Institute and was led by Dr. Aaron Thome and Dr. Stan Appel. The research article has been published in the Journal NeuroImmune Pharmacology and Therapeutics. The study found, among other things, that following pro-inflammatory activation of myeloid cells co-cultured with Tregs, the addition of COYA 301 (LD IL-2) alone enhanced Treg suppressive function by 15%. Similarly, when GLP-1RA alone was added to the system, Treg suppressive function increased by 20%. In contrast, when COYA 303 was added to the cell system a statistically significant increase in Treg suppressive function of 42% (p < 0.001) was observed, when compared to the increase observed with each of the single agents. Consistent with these results, treatment with COYA 303 promoted Treg survival by modulating the apoptotic pathway. COYA 303 significantly reduced BAX transcript levels during prolonged incubation (p < 0.01). These findings suggest a direct effect of COYA 303 supporting Treg survival through the inhibition of Treg apoptosis. We believe that these data show that the combination approach of COYA 303 enhances Treg suppressive function in highly inflammatory microenvironments, while also promoting Treg survival by preventing apoptosis.

On July 14, 2024, the U.S. Food and Drug Administration (the “FDA”), requested that we provide additional non-clinical data to support the initiation of a planned clinical study entitled “Phase 2, Randomized, Double-Blind, Placebo-Controlled, Multi-Center, 24-Week Study with Additional 24-Week Open Label Extension (OLE) to Evaluate the Safety and Efficacy of COYA 302 for the Treatment of Amyotrophic Lateral Sclerosis (ALS)” (the “Phase 2 Study”). On June 30, 2025, we re-submitted the Investigational New Drug Application (the “IND”) that includes the requested data to the FDA. Upon acceptance of the IND, we plan to initiate the Phase 2 study.

On July 29, 2025, the FDA informed us that due to the FDA’s present workload and lack of resources, they are unable to meet its initial review goal date for the IND of July 30, 2025. The FDA also informed us that they will provide their decision on approval of the IND as soon as possible, and expect that it will be provided no later than August 29, 2025.

Implications of Being an Emerging Growth Company

We qualify as an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act. An emerging growth company may take advantage of relief from certain reporting requirements and other burdens that are otherwise applicable generally to public companies. These provisions include:

• reduced obligations with respect to financial data, including presenting only two years of audited financial statements and only two years of selected financial data in this prospectus;

• an exception from compliance with the auditor attestation requirement of Section 404 of the Sarbanes-Oxley Act of 2002, as amended, or the Sarbanes-Oxley Act;

• reduced disclosure about our executive compensation arrangements in our periodic reports, proxy statements and registration statements; and

• exemptions from the requirements of holding non-binding advisory votes on executive compensation or golden parachute arrangements.

We may take advantage of exemptions for up to five years or such earlier time that we are no longer an emerging growth company. Accordingly, the information contained herein may be different than the information

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you receive from other public companies in which you hold stock. We would cease to be an emerging growth company upon the earliest to occur of: (1) the last day of the fiscal year in which we have more than $1.235 billion in annual gross revenue, (2) December 31, 2026, (3) the date we are deemed to be a “large accelerated filer” as defined in the Securities Exchange Act of 1934, as amended, or the Exchange Act, and (4) the date on which we have during the previous three-year period issued more than $1.0 billion in non-convertible debt securities.

The JOBS Act also permits us, as an emerging growth company, to take advantage of an extended transition period to comply with the new or revised accounting standards applicable to public companies and thereby allow us to delay the adoption of those standards until those standards would apply to private companies. We have irrevocably elected to avail ourselves of this exemption and therefore, we will not be subject to the same new or revised accounting standards as other public companies that are not emerging growth companies.

Corporate Information

Our primary executive offices are located at 5850 San Felipe St., Suite 500, Houston, TX 77057 and our telephone number is (800) 587-8170. Our website address is www.coyatherapeutics.com. The information contained in, or accessible through, our website does not constitute a part of this prospectus. We have included our website address in this prospectus solely as an inactive textual reference.

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RISK FACTORS

Investing in our securities involves significant risk. Before purchasing any of the securities you should carefully consider the risk factors incorporated by reference in this prospectus from our Annual Report on Form 10-K for the fiscal year ended December 31, 2024, filed with the SEC on March 18, 2025 (the “Annual Report”), and any subsequent updates described in our Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, as well as the risks, uncertainties and additional information set forth in our SEC reports on Forms 10-K, 10-Q and 8-K and in the other documents incorporated by reference in this prospectus. For a description of these reports and documents, and information about where you can find them, see “Additional Information” and “Incorporation of Certain Information By Reference.” Additional risks not presently known to us or that we presently consider to be immaterial could subsequently materially and adversely affect our financial condition, results of operations, business and prospects.

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and any documents we incorporate by reference, contain certain forward-looking statements that involve substantial risks and uncertainties. All statements contained in this prospectus and any documents we incorporate by reference, other than statements of historical facts, are forward-looking statements including statements regarding our strategy, future operations, future financial position, future revenue, projected costs, prospects, plans, objectives of management and expected market growth. 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.

The words “anticipate,” “believe,” “estimate,” “expect,” “intend,” “may,” “plan,” “predict,” “project,” “target,” “potential,” “will,” “would,” “could,” “should,” “continue” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. These forward-looking statements include, among other things, statements about:

• our ability to develop, obtain regulatory approval for and commercialize our product candidates;

• the timing of future investigational new drug (“IND”) submissions, initiation of preclinical studies and clinical trials, and timing of expected clinical results for our product candidates;

• our success in early preclinical studies, which may not be indicative of results obtained in later studies or clinical trials;

• the outbreak of public health emergencies, epidemics, pandemics, which could adversely impact our business, including our preclinical studies and any future clinical trials;

• the potential benefits of our product candidates;

• our ability to identify patients with the diseases treated by our product candidates, and to enroll patients in clinical trials;

• the success of our efforts to expand our pipeline of product candidates and develop marketable products through the use of our potential therapeutic modalities;

• our expectations regarding collaborations and other agreements with third parties and their potential benefits;

• our ability to obtain, maintain and protect our intellectual property;

• our reliance upon intellectual property licensed from third parties;

• impacts of increased trade tariffs, import quotas or other trade restrictions or measures taken by the United States and other countries, including the recent and potential changes in U.S. trade policies that may be made by the Trump presidential administration;

• our ability to identify, recruit and retain key personnel;

• our financial performance;

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

• the impact of laws and regulations;

• our expectations regarding the time during which we will be an emerging growth company under the JOBS Act; and

• other risks and uncertainties, including those listed in the “Risk Factors” section of this prospectus and the documents incorporated by reference herein.

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These forward-looking statements are only predictions and we may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, so you should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make. We have based these forward-looking statements largely on our current expectations and projections about future events and trends that we believe may affect our business, financial condition and operating results. We have included important factors in the cautionary statements included in this prospectus, as well as certain information incorporated by reference into this prospectus, that could cause actual future results or events to differ materially from the forward-looking statements that we make. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments we may make.

Discussions containing these forward-looking statements may be found, among other places, in the sections titled “Business,” “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” incorporated by reference from the Annual Report and our most recent Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2025, as well as any amendments thereto, filed with the SEC. Additional factors are discussed under the caption “Risk Factors” in this prospectus and any free writing prospectus and under similar headings in the other documents that are incorporated by reference into this prospectus. New risks and uncertainties arise from time to time, and it is impossible for us to predict these events or how they may affect us. We disclaim any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as may be required by law.

You should read this prospectus, and any accompanying prospectus supplement, with the understanding that our actual future results may be materially different from what we expect. We do not assume any obligation to update any forward-looking statements whether as a result of new information, future events or otherwise, except as required by applicable law.

You should rely only on this information in this prospectus, and in any applicable prospectus supplement. We have not authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely upon it.

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USE OF PROCEEDS

Unless we inform you otherwise in a prospectus supplement relating to a particular offering of securities, we will use the net proceeds from the sale of the securities offered by this prospectus and any applicable prospectus supplement and the exercise price from the exercise of any convertible securities, if any, for general corporate purposes, which may include funding administrative expenses, research and development, product manufacturing, preclinical studies, clinical trials, regulatory advancement of clinical candidates, acquisitions or investments in businesses, products or technologies that are complementary to our own, increasing our working capital, reducing indebtedness, and capital expenditures.

When particular securities are offered, the prospectus supplement relating to that offering will set forth our intended use of the net proceeds received from the sale of those securities we sell. Pending the application of the net proceeds for these purposes, we expect to invest the proceeds in short-term, interest-bearing instruments or other investment-grade securities. Management will retain broad discretion over the allocation of the net proceeds for any offering.

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THE SECURITIES WE MAY OFFER

General

The descriptions of the securities contained in this prospectus, together with the applicable prospectus supplements, summarize all of the material terms and provisions of the various types of securities that we may offer. We will describe in the applicable prospectus supplement relating to any securities the particular terms of the securities offered by that prospectus supplement. If we indicate in the applicable prospectus supplement, the terms of the securities may differ from the terms we have summarized below. We may also include in the prospectus supplement information about material United States federal income tax considerations relating to the securities, and the securities exchange, if any, on which the securities will be listed.

We may sell from time to time, in one or more offerings:

• common stock;

• preferred stock;

• warrants to purchase shares of common stock or preferred stock;

• debt securities;

• subscription rights to purchase shares of common stock, preferred stock or debt securities; and

• units consisting of any combination of the securities listed above.

In this prospectus, we refer to the common stock, preferred stock, debt securities, subscription rights, warrants and units collectively as “securities.” The total dollar amount of all securities that we may sell pursuant to this prospectus will not exceed $75,000,000.

If we issue debt securities at a discount from their original stated principal amount, then, for purposes of calculating the total dollar amount of all securities issued under this prospectus, we will treat the initial offering price of the debt securities as the total original principal amount of the debt securities.

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

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DESCRIPTION OF CAPITAL STOCK

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

General

Our authorized capital stock consists of 200,000,000 shares of common stock, par value $0.0001 per share, and 10,000,000 shares of preferred stock, par value $0.0001 per share.

As of August 8, 2025, there were 16,725,081 shares of common stock outstanding and no shares of preferred stock outstanding.

Common Stock

Holders of shares of our common stock are entitled to one vote for each share held of record on all matters on which stockholders are entitled to vote generally, including the election or removal of directors elected by our stockholders generally. The holders of our common stock do not have cumulative voting rights in the election of directors.

Holders of shares of our common stock are entitled to receive dividends when, as and if declared by our board of directors out of funds legally available therefor, subject to any statutory or contractual restrictions on the payment of dividends and to any restrictions on the payment of dividends imposed by the terms of any outstanding preferred stock.

Upon our liquidation, dissolution or winding up and after payment in full of all amounts required to be paid to creditors and to the holders of preferred stock having liquidation preferences, if any, the holders of shares of our common stock will be entitled to receive our remaining assets available for distribution on a pro rata basis.

All shares of our common stock are fully paid and non-assessable. The shares of our common stock are not subject to further calls or assessments by us. Holders of shares of our common stock do not have preemptive, subscription, redemption or conversion rights. There are no redemption or sinking fund provisions applicable to the common stock. The rights powers, preferences and privileges of our common stock are subject to those of the holders of any shares of our preferred stock or any other series or class of stock we may authorize and issue in the future.

Transfer Agent and Registrar

The transfer agent and registrar for shares of our common stock is Computershare Trust Company, N.A.

Preferred Stock

Our board of directors has the authority, without further action by our stockholders, to issue up to 10,000,000 shares of preferred stock in one or more classes or series. Our board of directors is able to determine, with respect to any series of preferred stock, the powers (including voting powers), preferences and relative, participating, optional or other special rights, and the qualifications, limitations or restrictions thereof, including, without limitation:

• the designation of the series;

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• the number of shares of the series, which our board of directors may, except where otherwise provided in the preferred stock designation, increase (but not above the total number of authorized shares of the class) or decrease (but not below the number of shares then outstanding);

• whether dividends, if any, will be cumulative or non-cumulative and the dividend rate of the series;

• the dates at which dividends, if any, will be payable;

• the redemption or repurchase rights and price or prices, if any, for shares of the series;

• the terms and amounts of any sinking fund provided for the purchase or redemption of shares of the series;

• the amounts payable on shares of the series in the event of any voluntary or involuntary liquidation, dissolution or winding-up of our affairs;

• whether the shares of the series will be convertible into shares of any other class or series, or any other security, of us or any other entity, and, if so, the specification of the other class or series or other security, the conversion price or prices or rate or rates, any rate adjustments, the date or dates as of which the shares will be convertible and all other terms and conditions upon which the conversion may be made;

• restrictions on the issuance of shares of the same series or of any other class or series; and

• the voting rights, if any, of the holders of the series.

We could issue a series of preferred stock that could, depending on the terms of the series, impede or discourage an acquisition attempt or other transaction that some, or a majority, of the holders of our common stock might believe to be in their best interests or in which the holders of our common stock might receive a premium over the market price of the shares of our common stock. Additionally, the issuance of preferred stock may adversely affect the rights of holders of our common stock by restricting dividends on the common stock, diluting the voting power of the common stock or subordinating the liquidation rights of the common stock. As a result of these or other factors, the issuance of preferred stock could have an adverse impact on the market price of our common stock.

Anti-Takeover Effects of Our Amended and Restated Certificate of Incorporation and Amended and Restated Bylaws and Certain Provisions of Delaware Law

Our amended and restated certificate of incorporation (“Amended Charter”), amended and restated bylaws (“Amended Bylaws”) and the Delaware General Corporation Law (the “DGCL”) contain provisions that are intended to enhance the likelihood of continuity and stability in the composition of our board of directors. These provisions are intended to avoid costly takeover battles, reduce our vulnerability to a hostile or abusive change of control and enhance the ability of our board of directors to maximize stockholder value in connection with any unsolicited offer to acquire us. However, these provisions may have an anti-takeover effect and may delay, deter or prevent a merger or acquisition of our company by means of a tender offer, a proxy contest or other takeover attempt that a stockholder might consider in its best interest, including those attempts that might result in a premium over the prevailing market price for the shares of common stock held by stockholders.

Potential Effects of Authorized but Unissued Stock

Pursuant to our Amended Charter, we have shares of common stock and preferred stock available for future issuance without stockholder approval. We may utilize these additional shares for a variety of corporate purposes, including future public offerings to raise additional capital, to facilitate corporate acquisitions or payment as a dividend on the capital stock.

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The existence of unissued and unreserved common stock and preferred stock may enable our board of directors to issue shares to persons friendly to current management or to issue preferred stock with terms that could render more difficult or discourage a third-party attempt to obtain control of us by means of a merger, tender offer, proxy contest or otherwise, thereby protecting the continuity of our management. In addition, the board of directors has the discretion to determine designations, rights, preferences, privileges and restrictions, including voting rights, dividend rights, conversion rights, redemption privileges and liquidation preferences of each series of preferred stock, all to the fullest extent permissible under the DGCL and subject to any limitations set forth in our Amended Charter. The purpose of authorizing the board of directors to issue preferred stock and to determine the rights and preferences applicable to such preferred stock is to eliminate delays associated with a stockholder vote on specific issuances. The issuance of preferred stock, while providing desirable flexibility in connection with possible financings, acquisitions and other corporate purposes, could have the effect of making it more difficult for a third-party to acquire, or could discourage a third-party from acquiring, a majority of our outstanding voting stock.

Business Combinations

We are subject to Section 203 of the DGCL, which prohibits a Delaware corporation from engaging in any business combination with any interested stockholder for a period of three years after the date that such stockholder became an interested stockholder, with the following exceptions:

• before such date, the board of directors of the corporation approved either the business combination or the transaction that resulted in the stockholder becoming an interested stockholder;

• upon completion of the transaction that resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of the voting stock of the corporation outstanding at the time the transaction began, excluding for purposes of determining the voting stock outstanding (but not the outstanding voting stock owned by the interested stockholder) those shares owned (i) by persons who are directors and also officers and (ii) 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 after such date, the business combination is approved by the board of directors and authorized at an annual or special meeting of the stockholders, and not by written consent, by the affirmative vote of at least 66 2/3% of the outstanding voting stock that is not owned by the interested stockholder.

In general, Section 203 defines a “business combination” to include the following:

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

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

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

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

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

In general, Section 203 defines an “interested stockholder” as an entity or person who, together with the person’s affiliates and associates, beneficially owns, or within three years prior to the time of determination of interested stockholder status did own, 15% or more of the outstanding voting stock of the corporation.

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No Cumulative Voting

Under Delaware law, the right to vote cumulatively does not exist unless the certificate of incorporation specifically authorizes cumulative voting. Our Amended Charter does not authorize cumulative voting. Therefore, stockholders holding a majority of the shares of our stock entitled to vote generally in the election of directors will be able to elect all our directors.

Special Stockholder Meetings

Our Amended Charter provides that special meetings of our stockholders may be called at any time only by or at the direction of the board of directors, the chairman of the board of directors or our chief executive officer. Our Amended Bylaws prohibit the conduct of any business at a special meeting other than as specified in the notice for such meeting. These provisions may have the effect of deferring, delaying, or discouraging hostile takeovers, or changes in control or management of our company.

Director Nominations and Stockholder Proposals

Our Amended Bylaws establish advance notice procedures with respect to stockholder proposals and the nomination of candidates for election as directors, other than nominations made by or at the direction of the board of directors or a committee of the board of directors. In order for any matter to be “properly brought” before a meeting, a stockholder will have to comply with advance notice requirements and provide us with certain information. Generally, to be timely, a stockholder’s notice must be received at our principal executive offices not less than 90 days nor more than 120 days prior to the first anniversary date of the immediately preceding annual meeting of stockholders. However, in the event that the date of the annual meeting is more than 30 days before or more than 70 days after the anniversary date, notice by the stockholder must be delivered not earlier than the close of business on the 120th day prior to the annual meeting and not later than the close of business on the later of the 90th day prior to the annual meeting or the 10th day following the day on which public announcement of the date of the meeting is first made by us.

Our Amended Bylaws also specify requirements as to the form and content of a stockholder’s notice. Our Amended Bylaws allow the chairman of the meeting at a meeting of the stockholders to adopt rules and regulations for the conduct of meetings that may have the effect of precluding the conduct of certain business at a meeting if the rules and regulations are not followed. These provisions may also defer, delay, or discourage a potential acquirer from conducting a solicitation of proxies to elect the acquirer’s own slate of directors or otherwise attempting to influence or obtain control of the company.

Amendment of Our Amended Charter or Amended Bylaws

The DGCL provides generally that the affirmative vote of a majority of the shares entitled to vote on any matter is required to amend a corporation’s certificate of incorporation or bylaws, unless a corporation’s certificate of incorporation or bylaws, as the case may be, requires a greater percentage. Our Amended Bylaws may be amended or repealed by a majority vote of our board of directors or by the affirmative vote of the holders of at least 66 2/3% of the votes which all our stockholders would be entitled to cast in any annual election of directors. In addition, the affirmative vote of the holders of at least 66 2/3% of the votes which all our stockholders would be entitled to cast in any election of directors will be required to amend or repeal or to adopt any provisions inconsistent with any of the provisions of our certificate described above.

The foregoing provisions of our Amended Charter and Amended Bylaws could discourage potential acquisition proposals and could delay or prevent a change in control. These provisions are intended to enhance the likelihood of continuity and stability in the composition of our board of directors and in the policies formulated by our board of directors and to discourage certain types of transactions that may involve an actual or threatened change of control. These provisions are designed to reduce our vulnerability to an unsolicited

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acquisition proposal. The provisions also are intended to discourage certain tactics that may be used in proxy fights. However, such provisions could have the effect of discouraging others from making tender offers for our shares and, as a consequence, they also may inhibit fluctuations in the market price of our shares of common stock that could result from actual or rumored takeover attempts. Such provisions also may have the effect of preventing changes in our management or delaying or preventing a transaction that might benefit you or other minority stockholders.

Dissenters’ Rights of Appraisal and Payment

Under the DGCL, with certain exceptions, our stockholders will have appraisal rights in connection with a merger or consolidation of us. Pursuant to the DGCL, stockholders who properly request and perfect appraisal rights in connection with such merger or consolidation will have the right to receive payment of the fair value of their shares as determined by the Delaware Court of Chancery.

Stockholders’ Derivative Actions

Under the DGCL, any of our stockholders may bring an action in our name to procure a judgment in our favor, also known as a derivative action, provided that the stockholder bringing the action is a holder of our shares at the time of the transaction to which the action relates or such stockholder’s stock thereafter devolved by operation of law.

Choice of Forum

Our Amended Charter provides that, unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware shall be the sole and exclusive forum for any stockholder to bring (i) any derivative action or proceeding brought on behalf of the Company, (ii) any action asserting a claim of breach of fiduciary duty owed by any current or former director, officer or other employee of the Company or the Company’s stockholders, (iii) any action asserting a claim against the Company or any director or officer of the Company arising pursuant to, or a claim against the Company or any director or officer of the Company, with respect to the interpretation or application of any provision of, the DGCL, our Amended Charter or Amended Bylaws, or (iv) any action asserting a claim governed by the internal affairs doctrine, except for, in each of the aforementioned actions, any claims to which the Court of Chancery of the State of Delaware determines it lacks jurisdiction. This provision does not apply to claims arising under the Exchange Act, or for any other federal securities laws which provide for exclusive federal jurisdiction. However, the exclusive forum provision provides that unless we consent in writing to the selection of an alternative forum, the federal district courts of the United States of America is the exclusive forum for the resolution of any complaint asserting a cause of action arising under the Securities Act of 1933, or the Securities Act. Therefore, this provision could apply to a suit that falls within one or more of the categories enumerated in the exclusive forum provision and that asserts claims under the Securities Act, inasmuch as Section 22 of the Securities Act creates concurrent jurisdiction for federal and state courts over all suits brought to enforce any duty or liability created by the Securities Act or the rules and regulations thereunder. There is uncertainty as to whether a court would enforce such an exclusive forum provision with respect to claims under the Securities Act.

We note that there is uncertainty as to whether a court would enforce the provision and that investors cannot waive compliance with the federal securities laws and the rules and regulations thereunder. Although we believe this provision benefits us by providing increased consistency in the application of Delaware law in the types of lawsuits to which it applies, the provision may have the effect of discouraging lawsuits against our directors and officers.

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DESCRIPTION OF STOCK WARRANTS

We summarize below some of the provisions that will apply to the warrants unless the applicable prospectus supplement provides otherwise. This summary may not contain all information that is important to you. The complete terms of the warrants will be contained in the applicable warrant certificate and warrant agreement. These documents have been or will be included or incorporated by reference as exhibits to the registration statement of which this prospectus is a part. You should read the warrant certificate and the warrant agreement. You should also read the prospectus supplement, which will contain additional information and which may update or change some of the information below.

General

We may issue, together with common or preferred stock as units or separately, warrants for the purchase of shares of our common or preferred stock. The terms of each warrant will be discussed in the applicable prospectus supplement relating to the particular series of warrants. The form(s) of certificate representing the warrants and/or the warrant agreement will be, in each case, filed with the SEC as an exhibit to a document incorporated by reference in the registration statement of which this prospectus is a part on or prior to the date of any prospectus supplement relating to an offering of the particular warrant. The following summary 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 a particular series of warrants.

The prospectus supplement relating to any series of warrants that are offered by this prospectus will describe, among other things, the following terms to the extent they are applicable to that series of warrants:

• the procedures and conditions relating to the exercise of the warrants;

• the number of shares of our common or preferred stock, if any, issued with the warrants;

• the date, if any, on and after which the warrants and any related shares of our common or preferred stock will be separately transferable;

• the offering price of the warrants, if any;

• the number of shares of our common or preferred stock which may be purchased upon exercise of the warrants and the price or prices at which the shares may be purchased upon exercise;

• the date on which the right to exercise the warrants will begin and the date on which the right will expire;

• a discussion of the material United States federal income tax considerations applicable to the exercise of the warrants;

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

• call provisions of the warrants, if any; and

• any other material terms of the warrants.

Each warrant may entitle the holder to purchase for cash, or, in limited circumstances, by effecting a cashless exercise for, the number of shares of our common or preferred stock at the exercise price that is described in the applicable prospectus supplement. Warrants will be exercisable during the period of time described in the applicable prospectus supplement. After that period, unexercised warrants will be void. Warrants may be exercised in the manner described in the applicable prospectus supplement.

A holder of a warrant will not have any of the rights of a holder of our common or preferred stock before the stock is purchased upon exercise of the warrant. Therefore, before a warrant is exercised, the holder of the warrant will not be entitled to receive any dividend payments or exercise any voting or other rights associated with shares of our common or preferred stock which may be purchased when the warrant is exercised.

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Transfer Agent and Registrar

The transfer agent and registrar, if any, for any warrants will be set forth in the applicable prospectus supplement.

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DESCRIPTION OF DEBT SECURITIES

This prospectus describes certain general terms and provisions of debt securities that we may offer. The debt securities may be issued pursuant to, in the case of senior debt securities, a senior indenture, and in the case of subordinated debt securities, a subordinated indenture, in each case in the forms filed as exhibits to this registration statement, which we refer to as the “indentures.” The indentures will be entered into between us and a trustee to be named prior to the issuance of any debt securities, which we refer to as the “trustee.” The indentures will not limit the amount of debt securities that can be issued thereunder and will provide that the debt securities may be issued from time to time in one or more series pursuant to the terms of one or more securities resolutions or supplemental indentures creating such series.

We have summarized below the material provisions of the indentures and the debt securities or indicated which material provisions will be described in the related prospectus supplement for any offering of debt securities. These descriptions are only summaries, and you should refer to the relevant indenture for the particular offering of debt securities itself which will describe completely the terms and definitions of the offered debt securities and contain additional information about the debt securities.

Terms

When we offer to sell a particular series of debt securities, we will describe the specific terms of the securities in a prospectus supplement. The prospectus supplement will set forth the following terms, as applicable, of the debt securities offered thereby:

• the designation, aggregate principal amount, currency or composite currency and denominations;

• the price at which such debt securities will be issued and, if an index formula or other method is used, the method for determining amounts of principal or interest;

• the maturity date and other dates, if any, on which principal will be payable;

• 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;

• the interest rate (which may be fixed or variable), if any;

• the date or dates from which interest will accrue and on which interest will be payable, and the record dates for the payment of interest;

• the manner of paying principal and interest;

• the place or places where principal and interest will be payable;

• the terms of any mandatory or optional redemption by us or any third party including any sinking fund;

• the terms of any conversion or exchange;

• the terms of any redemption at the option of holders or put by the holders;

• any tax indemnity provisions;

• if the debt securities provide that payments of principal or interest may be made in a currency other than that in which the debt securities are denominated, the manner for determining such payments;

• the portion of principal payable upon acceleration of a Discounted Debt Security (as defined below);

• whether and upon what terms debt securities may be defeased;

• any events of default or covenants in addition to or in lieu of those set forth in the indentures;

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• provisions for electronic issuance of debt securities or for the issuance of debt securities in uncertificated form; and

• any additional provisions or other special terms not inconsistent with the provisions of the indentures, including any terms that may be required or advisable under United States or other applicable laws or regulations, or advisable in connection with the marketing of the debt securities.

Debt securities of any series may be issued as registered debt securities or uncertificated debt securities, in such denominations as specified in the terms of the series.

Securities may be issued under the indentures as Discounted Debt Securities to be offered and sold at a substantial discount from the principal amount thereof. Special United States federal income tax and other considerations applicable thereto will be described in the prospectus supplement relating to such Discounted Debt Securities. “Discounted Debt Security” means a security where the amount of principal due upon acceleration is less than the stated principal amount.

We are not obligated to issue all debt securities of one series at the same time and, unless otherwise provided in the prospectus supplement, we may reopen a series, without the consent of the holders of the debt securities of that series, for the issuance of additional debt securities of that series. Additional debt securities of a particular series will have the same terms and conditions as outstanding debt securities of such series, except for the date of original issuance and the offering price, and will be consolidated with, and form a single series with, such outstanding debt securities.

Ranking

The senior debt securities will rank equally with all of our other senior and unsubordinated debt. Our secured debt, if any, will be effectively senior to the senior debt securities to the extent of the value of the assets securing such debt. The subordinated debt securities will be subordinate and junior in right of payment to all of our present and future senior indebtedness to the extent and in the manner described in the prospectus supplement and as set forth in the board resolution, officer’s certificate or supplemental indenture relating to such offering.

We have only a stockholder’s claim on the assets of our subsidiaries. This stockholder’s claim is junior to the claims that creditors of our subsidiaries have against our subsidiaries. Holders of our debt securities will be our creditors and not creditors of any of our subsidiaries. As a result, all the existing and future liabilities of our subsidiaries, including any claims of their creditors, will effectively be senior to the debt securities with respect to the assets of our subsidiaries. In addition, to the extent that we issue any secured debt, the debt securities will be effectively subordinated to such secured debt to the extent of the value of the assets securing such secured debt.

The debt securities will be obligations exclusively of Coya Therapeutics, Inc. To the extent that our ability to service our debt, including the debt securities, may be dependent upon the earnings of our subsidiaries, our ability to do so will be dependent on the ability of our subsidiaries to distribute those earnings to us as dividends, loans or other payments.

Certain Covenants

Any covenants that may apply to a particular series of debt securities will be described in the prospectus supplement relating thereto.

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Successor Obligor

The indentures will provide that, unless otherwise specified in the securities resolution or supplemental indenture establishing a series of debt securities, we shall not consolidate with or merge into, or transfer all or substantially all of our assets to, any person in any transaction in which we are not the survivor, unless:

• the person is organized under the laws of the United States or a jurisdiction within the United States;

• the person assumes by supplemental indenture all of our obligations under the relevant indenture, the debt securities and any coupons;

• immediately after the transaction no Default (as defined below) exists; and

• we deliver to the trustee an officers’ certificate and opinion of counsel stating that the transaction complies with the foregoing requirements and that all conditions precedent provided for in the indenture relating to the transaction have been complied with.

In such event, the successor will be substituted for us, and thereafter all of our obligations under the relevant indenture, the debt securities and any coupons will terminate.

The indentures will provide that these limitations shall not apply if our board of directors makes a good faith determination that the principal purpose of the transaction is to change our state of incorporation.

Exchange of Debt Securities

Registered debt securities may be exchanged for an equal aggregate principal amount of registered debt securities of the same series and date of maturity in such authorized denominations as may be requested upon surrender of the registered debt securities at an agency of the Company maintained for such purpose and upon fulfillment of all other requirements of such agent.

Default and Remedies

Unless the securities resolution or supplemental indenture establishing the series otherwise provides (in which event the prospectus supplement will so state), an “Event of Default” with respect to a series of debt securities will occur if:

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

• we default in the payment of all or any part of the principal and premium, if any, of any debt securities of such series when the same becomes due and payable at maturity or upon redemption, acceleration or otherwise and such default shall continue for five or more days;

• we default in the performance of any of our other agreements applicable to the series and the default continues for 30 days after the notice specified below;

• a court of competent jurisdiction enters an order or decree under any Bankruptcy Law (as defined below) that:

i. is for relief against us in an involuntary case,

ii. appoints a Custodian (as defined below) for us or for any substantial part of our property, or

iii. orders the winding up or liquidation of us, and the order or decree remains unstayed and in effect for 90 days;

• we, pursuant to or within the meaning of any Bankruptcy Law:

i. commence a voluntary case,

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ii. consent to the entry of an order for relief against us in an involuntary case,

iii. consent to the appointment of a Custodian for us or for any substantial part of our property, or

iv. make a general assignment for the benefit of our creditors; or

• there occurs any other Event of Default provided for in such series.

The term “Bankruptcy Law” means Title 11 of the United States Code or any similar Federal or State law for the relief of debtors. The term “Custodian” means any receiver, trustee, assignee, liquidator or a similar official under any Bankruptcy Law.

“Default” means any event which is, or after notice or passage of time would be, an Event of Default. A Default under subparagraph (3) above is not an Event of Default until the trustee or the holders of at least 25% in principal amount of the series notify us of the Default and we do not cure the Default within the time specified after receipt of the notice.

The trustee may require indemnity satisfactory to it before it enforces the indentures or the debt securities of the series. Subject to certain limitations, holders of a majority in principal amount of the debt securities of the series may direct the trustee in its exercise of any trust or power with respect to such series. Except in the case of Default in payment on a series, the trustee may withhold from securityholders of such series notice of any continuing Default if the trustee determines that withholding notice is in the interest of such securityholders. We are required to furnish the trustee annually a brief certificate as to our compliance with all conditions and covenants under the indentures.

The indentures will not have cross-default provisions. Thus, a default by us on any other debt, including any other series of debt securities, would not constitute an Event of Default.

Amendments and Waivers

The indentures and the debt securities or any coupons of the series may be amended, and any Default may be waived as follows:

Unless the securities resolution or supplemental indenture otherwise provides (in which event the applicable prospectus supplement will so state), the debt securities and the indentures may be amended with the consent of the holders of a majority in principal amount of the debt securities of all series affected voting as one class. Unless the securities resolution or supplemental indenture otherwise provides (in which event the applicable prospectus supplement will so state), a Default other than a Default in payment on a particular series may be waived with the consent of the holders of a majority in principal amount of the debt securities of the series. However, without the consent of each securityholder affected, no amendment or waiver may:

• change the fixed maturity of or the time for payment of interest on any debt security;

• reduce the principal, premium or interest payable with respect to any debt security;

• change the place of payment of a debt security or the currency in which the principal or interest on a debt security is payable;

• change the provisions for calculating any redemption or repurchase price with respect to any debt security;

• adversely affect any holder’s right to receive payment of principal and interest or to institute suit for the enforcement of any such payment;

• reduce the amount of debt securities whose holders must consent to an amendment or waiver;

• make any change that materially adversely affects the right to convert any debt security;

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• waive any Default in payment of principal of or interest on a debt security; or

• adversely affect any holder’s rights with respect to redemption or repurchase of a debt security.

Without the consent of any securityholder, the indentures or the debt securities may be amended to:

• provide for assumption of our obligations to securityholders in the event of a merger or consolidation requiring such assumption;

• cure any ambiguity, omission, defect or inconsistency;

• conform the terms of the debt securities to the description thereof in the prospectus and prospectus supplement offering such debt securities;

• create a series and establish its terms;

• provide for the acceptance of appointment by a successor trustee or to facilitate the administration of the trusts by more than one trustee;

• provide for uncertificated or unregistered securities;

• make any change that does not adversely affect the rights of any securityholder;

• add to our covenants; or

• make any other change to the indentures so long as no debt securities are outstanding.

Conversion Rights

Any securities resolution or supplemental indenture establishing a series of debt securities may provide that the debt securities of such series will be convertible at the option of the holders thereof into or for our common stock or other equity or debt instruments. The securities resolution or supplemental indenture may establish, among other things, (1) the number or amount of shares of common stock or other equity or debt instruments for which $1,000 aggregate principal amount of the debt securities of the series is convertible, as may be adjusted pursuant to the terms of the relevant indenture and the securities resolution; and (2) provisions for adjustments to the conversion rate and limitations upon exercise of the conversion right. The indentures provide that we will not be required to make an adjustment in the conversion rate unless the adjustment would require a cumulative change of at least 1% in the conversion rate. However, we will carry forward any adjustments that are less than 1% of the conversion rate and take them into account in any subsequent adjustment of the conversion rate.

Legal Defeasance and Covenant Defeasance

Debt securities of a series may be defeased in accordance with their terms and, unless the securities resolution or supplemental indenture establishing the terms of the series otherwise provides, as set forth below. We at any time may terminate as to a series all of our obligations (except for certain obligations, including obligations with respect to the defeasance trust and obligations to register the transfer or exchange of a debt security, to replace destroyed, lost or stolen debt securities and coupons and to maintain paying agencies in respect of the debt securities) with respect to the debt securities of the series and any related coupons and the relevant indenture, which we refer to as legal defeasance. We at any time may terminate as to a series our obligations with respect to any restrictive covenants which may be applicable to a particular series, which we refer to as covenant defeasance.

We may exercise our legal defeasance option notwithstanding our prior exercise of our covenant defeasance option. If we exercise our legal defeasance option, a series may not be accelerated because of an Event of Default. If we exercise our covenant defeasance option, a series may not be accelerated by reference to any covenant which may be applicable to a series.

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To exercise either defeasance option as to a series, we must (1) irrevocably deposit in trust with the trustee (or another trustee) money or U.S. Government Obligations (as defined below), deliver a certificate from a nationally recognized firm of independent accountants expressing their opinion that the payments of principal and interest when due on the deposited U.S. Government Obligations, without reinvestment, plus any deposited money without investment will provide cash at such times and in such amounts as will be sufficient to pay the principal and interest when due on all debt securities of such series to maturity or redemption, as the case may be; and (2) comply with certain other conditions. In particular, we must obtain an opinion of tax counsel that the defeasance will not result in recognition of any gain or loss to holders for federal income tax purposes.

“U.S. Government Obligations” means direct obligations of the United States or any agency or instrumentality of the United States, the payment of which is unconditionally guaranteed by the United States, which, in either case, have the full faith and credit of the United States pledged for payment and which are not callable at the issuer’s option, or certificates representing an ownership interest in such obligations.

Regarding the Trustee

Unless otherwise indicated in a prospectus supplement, the trustee will also act as depository of funds, transfer agent, paying agent and conversion agent, as applicable, with respect to the debt securities. In certain circumstances, we or the securityholders may remove the trustee as the trustee under a given indenture. The indenture trustee may also provide additional unrelated services to us as a depository of funds, registrar, trustee and similar services.

Governing Law

The indentures and the debt securities will be governed by New York law, except to the extent that the Trust Indenture Act of 1939 is applicable.

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DESCRIPTION OF SUBSCRIPTION RIGHTS

We may issue subscription rights to purchase our equity or debt securities. These subscription rights may be offered independently or together with any other security offered hereby and may or may not be transferable by the stockholder receiving the subscription rights in such offering. In connection with any offering of subscription rights, we may enter into a standby arrangement with one or more underwriters or other purchasers pursuant to which the underwriters or other purchasers may be required to purchase any securities remaining unsubscribed for after such offering.

The prospectus supplement relating to any subscription rights we offer, if any, will, to the extent applicable, include specific terms relating to the offering, including some or all of the following:

• the price, if any, for the subscription rights;

• the exercise price payable for our equity or debt securities upon the exercise of the subscription rights;

• the number of subscription rights to be issued to each stockholder;

• the number and terms of our equity or debt securities which may be purchased per each subscription right;

• the extent to which the subscription rights are transferable;

• any other terms of the subscription rights, including the terms, procedures and limitations relating to the exchange and exercise of the subscription rights;

• the date on which the right to exercise the subscription rights shall commence, and the date on which the subscription rights shall expire;

• the extent to which the subscription rights may include an over-subscription privilege with respect to unsubscribed securities or an over-allotment privilege to the extent the securities are fully subscribed; and

• if applicable, the material terms of any standby underwriting or purchase arrangement which may be entered into by us in connection with the offering of subscription rights.

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DESCRIPTION OF UNITS

We may issue units comprised of one or more of the other securities described in this prospectus in any combination. Each unit will be issued so that the holder of the unit is also the holder of each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each included security (but, to the extent convertible securities are included in the units, the holder of the units will be deemed the holder of the convertible securities and not the holder of the underlying securities). The unit agreement under which a unit is issued, if any, may provide that the securities included in the unit may not be held or transferred separately, at any time or at any time before a specified date. The applicable prospectus supplement may describe:

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

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

• the terms of the unit agreement governing the units;

• United States federal income tax considerations relevant to the units; and

• whether the units will be issued in fully registered global form.

This summary of certain general terms of units and any summary description of units in the applicable prospectus supplement do not purport to be complete and are qualified in their entirety by reference to all provisions of the applicable unit agreement and, if applicable, collateral arrangements and depositary arrangements relating to such units. The forms of the unit agreements and other documents relating to a particular issue of units will be filed with the SEC each time we issue units, and you should read those documents for provisions that may be important to you.

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FORMS OF SECURITIES

Each debt security and, to the extent applicable, warrant, subscription right and unit, will be represented either by a certificate issued in definitive form to a particular investor or by one or more global securities representing the entire issuance of securities. Certificated securities in definitive form and global securities will be issued in registered form. Definitive securities name you or your nominee as the owner of the security, and in order to transfer or exchange these securities or to receive payments other than interest or other interim payments, you or your nominee must physically deliver the securities to the trustee, registrar, paying agent or other agent, as applicable. Global securities name a depositary or its nominee as the owner of the debt securities or warrants represented by these global securities. The depositary maintains a computerized system that will reflect each investor’s beneficial ownership of the securities through an account maintained by the investor with its broker/dealer, bank, trust company or other representative, as we explain more fully below.

Global Securities

Registered Global Securities. We may issue the registered debt securities and, to the extent applicable, warrants, subscription rights and units, in the form of one or more fully registered global securities that will be deposited with a depositary or its nominee identified in the applicable prospectus supplement and registered in the name of that depositary or nominee. In those cases, one or more registered global securities will be issued in a denomination or aggregate denominations equal to the portion of the aggregate principal or face amount of the securities to be represented by registered global securities. Unless and until it is exchanged in whole for securities in definitive registered form, a registered global security may not be transferred except as a whole by and among the depositary for the registered global security, the nominees of the depositary or any successors of the depositary or those nominees.

If not described below, any specific terms of the depositary arrangement with respect to any securities to be represented by a registered global security will be described in the prospectus supplement relating to those securities. We anticipate that the following provisions will apply to all depositary arrangements.

Ownership of beneficial interests in a registered global security will be limited to persons, called participants, that have accounts with the depositary or persons that may hold interests through participants. Upon the issuance of a registered global security, the depositary will credit, on its book-entry registration and transfer system, the participants’ accounts with the respective principal or face amounts of the securities beneficially owned by the participants. Any dealers, underwriters or agents participating in the distribution of the securities will designate the accounts to be credited. Ownership of beneficial interests in a registered global security will be shown on, and the transfer of ownership interests will be effected only through, records maintained by the depositary, with respect to interests of participants, and on the records of participants, with respect to interests of persons holding through participants. The laws of some states may require that some purchasers of securities take physical delivery of these securities in definitive form. These laws may impair your ability to own, transfer or pledge beneficial interests in registered global securities.

So long as the depositary, or its nominee, is the registered owner of a registered global security, that depositary or its nominee, as the case may be, will be considered the sole owner or holder of the securities represented by the registered global security for all purposes under the applicable indenture or warrant agreement. Except as described below, owners of beneficial interests in a registered global security will not be entitled to have the securities represented by the registered global security registered in their names, will not receive or be entitled to receive physical delivery of the securities in definitive form and will not be considered the owners or holders of the securities under the applicable indenture or warrant agreement. Accordingly, each person owning a beneficial interest in a registered global security must rely on the procedures of the depositary for that registered global security and, if that person is not a participant, on the procedures of the participant through which the person owns its interest, to exercise any rights of a holder under the applicable indenture or warrant agreement. We understand that under existing industry practices, if we request any action of holders or if

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an owner of a beneficial interest in a registered global security desires to give or take any action that a holder is entitled to give or take under the applicable indenture or warrant agreement, the depositary for the registered global security would authorize the participants holding the relevant beneficial interests to give or take that action, and the participants would authorize beneficial owners owning through them to give or take that action or would otherwise act upon the instructions of beneficial owners holding through them.

Principal, premium, if any, interest payments on debt securities and any payments to holders with respect to warrants represented by a registered global security registered in the name of a depositary or its nominee will be made to the depositary or its nominee, as the case may be, as the registered owner of the registered global security. None of the Company, the trustees, the warrant agents or any other agent of the Company, agent of the trustees or warrant agents will have any responsibility or liability for any aspect of the records relating to payments made on account of beneficial ownership interests in the registered global security or for maintaining, supervising or reviewing any records relating to those beneficial ownership interests.

We expect that the depositary for any of the securities represented by a registered global security, upon receipt of any payment of principal, premium, interest or other distribution of underlying securities or other property to holders on that registered global security, will immediately credit participants’ accounts in amounts proportionate to their respective beneficial interests in that registered global security as shown on the records of the depositary. We also expect that payments by participants to owners of beneficial interests in a registered global security held through participants will be governed by standing customer instructions and customary practices, as is now the case with the securities held for the accounts of customers in bearer form or registered in “street name,” and will be the responsibility of those participants.

If the depositary for any of these securities represented by a registered global security is at any time unwilling or unable to continue as depositary or ceases to be a clearing agency registered under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and a successor depositary registered as a clearing agency under the Exchange Act is not appointed by us within 90 days, we will issue securities in definitive form in exchange for the registered global security that had been held by the depositary. Any securities issued in definitive form in exchange for a registered global security will be registered in the name or names that the depositary gives to the relevant trustee or warrant agent or other relevant agent of ours or theirs. It is expected that the depositary’s instructions will be based upon directions received by the depositary from participants with respect to ownership of beneficial interests in the registered global security that had been held by the depositary.

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PLAN OF DISTRIBUTION

Initial Offering and Sale of Securities

Unless otherwise set forth in a prospectus supplement accompanying this prospectus, we may sell the securities being offered hereby, from time to time, by one or more of the following methods:

• to or through underwriting syndicates represented by managing underwriters;

• through one or more underwriters without a syndicate for them to offer and sell to the public;

• through dealers or agents; and

• to investors directly in negotiated sales or in competitively bid transactions.

Offerings of securities covered by this prospectus also may be made into an existing trading market for those securities in transactions at other than a fixed price, either:

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

• to or through a market maker other than on the securities exchanges or quotation or trading services set forth above.

Those at-the-market offerings, if any, will be conducted by underwriters acting as principal or agent of the Company, who may also be third-party sellers of securities as described above. The prospectus supplement with respect to the offered securities will set forth the terms of the offering of the offered securities, including:

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

• the purchase price of the offered securities and the proceeds to us from such sale;

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

• any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers;

• any securities exchange on which such offered securities may be listed; and

• any underwriter, agent or dealer involved in the offer and sale of any series of the securities.

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

• at fixed prices, which may be changed;

• at market prices prevailing at the time of the sale;

• at varying prices determined at the time of sale; or

• at negotiated prices.

Each prospectus supplement will set forth the manner and terms of an offering of securities including:

• whether that offering is being made to underwriters, through agents or directly to the public;

• the rules and procedures for any auction or bidding process, if used;

• the securities’ purchase price or initial public offering price; and

• the proceeds we anticipate from the sale of the securities, if any.

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In addition, we may enter into derivative or hedging transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. The applicable prospectus supplement may indicate, in connection with such a transaction, that the third parties may sell securities covered by and pursuant to this prospectus and an applicable prospectus supplement. If so, the third party may use securities pledged by us or borrowed from us or others to settle such sales and may use securities received from us to close out any related short positions. We may also loan or pledge securities covered by this prospectus and an applicable prospectus supplement to third parties, who may sell the loaned securities or, in an event of default in the case of a pledge, sell the pledged securities pursuant to this prospectus and the applicable prospectus supplement.

Sales Through Underwriters

If underwriters are used in the sale of some or all of the securities covered by this prospectus, the underwriters will acquire the securities for their own account. The underwriters may resell the securities, either directly to the public or to securities dealers, at various times in one or more transactions, including negotiated 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 certain conditions. Unless indicated otherwise in a prospectus supplement, the underwriters will be obligated to purchase all the securities of the series offered if any of the securities are purchased.

Any initial public offering price and any concessions allowed or reallowed to dealers may be changed intermittently.

Sales Through Agents

Unless otherwise indicated in the applicable prospectus supplement, when securities are sold through an agent, the designated agent will agree, for the period of its appointment as agent, to use specified efforts to sell the securities for our account and will receive commissions from us as will be set forth in the applicable prospectus supplement.

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

If so indicated in the applicable prospectus supplement, we may authorize agents, underwriters or dealers to solicit offers by certain specified institutions to purchase securities at a price set forth in the prospectus supplement pursuant to delayed delivery contracts providing for payment and delivery on a future date specified in the prospectus supplement. These contracts will be subject only to those conditions set forth in the applicable prospectus supplement, and the prospectus supplement will set forth the commissions payable for solicitation of these contracts.

Direct Sales

We may also sell offered securities directly to institutional investors or others. In this case, no underwriters or agents would be involved. The terms of such sales will be described in the applicable prospectus supplement.

General Information

Broker-dealers, agents or underwriters may receive compensation in the form of discounts, concessions or commissions from us and/or the purchasers of securities for whom such broker-dealers, agents or underwriters may act as agents or to whom they sell as principal, or both. This compensation to a particular broker-dealer might be in excess of customary commissions.

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Underwriters, dealers and agents that participate in any distribution of the offered securities may be deemed “underwriters” within the meaning of the Securities Act, so any discounts or commissions they receive in connection with the distribution may be deemed to be underwriting compensation. Those underwriters and agents may be entitled, under their agreements with us, to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, or to contribution by us to payments that they may be required to make in respect of those civil liabilities. Certain of those underwriters or agents may be customers of, engage in transactions with, or perform services for, us or our affiliates in the ordinary course of business. We will identify any underwriters or agents, and describe their compensation, in a prospectus supplement. Any institutional investors or others that purchase offered securities directly, and then resell the securities, may be deemed to be underwriters, and any discounts or commissions received by them from us and any profit on the resale of the securities by them may be deemed to be underwriting discounts and commissions under the Securities Act.

We will file a supplement to this prospectus, if required, pursuant to Rule 424(b) under the Securities Act, if we enter into any material arrangement with a broker, dealer, agent or underwriter for the sale of securities through a block trade, special offering, exchange distribution or secondary distribution or a purchase by a broker or dealer. Such prospectus supplement will disclose:

• the name of any participating broker, dealer, agent or underwriter;

• the number and type of securities involved;

• the price at which such securities were sold;

• any securities exchanges on which such securities may be listed;

• the commissions paid or discounts or concessions allowed to any such broker, dealer, agent or underwriter, where applicable; and

• other facts material to the transaction.

In order to facilitate the offering of certain securities under this prospectus or an applicable prospectus supplement, certain persons participating in the offering of those securities may engage in transactions that stabilize, maintain or otherwise affect the price of those securities during and after the offering of those securities. Specifically, if the applicable prospectus supplement permits, the underwriters of those securities may over-allot or otherwise create a short position in those securities for their own account by selling more of those securities than have been sold to them by us and may elect to cover any such short position by purchasing those securities in the open market.

In addition, the underwriters may stabilize or maintain the price of those securities by bidding for or purchasing those securities in the open market and may impose penalty bids, under which selling concessions allowed to syndicate members or other broker-dealers participating in the offering are reclaimed if securities previously distributed in the offering are repurchased in connection with stabilization transactions or otherwise. The effect of these transactions may be to stabilize or maintain the market price of the securities at a level above that which might otherwise prevail in the open market. The imposition of a penalty bid may also affect the price of securities to the extent that it discourages resales of the securities. No representation is made as to the magnitude or effect of any such stabilization or other transactions. Such transactions, if commenced, may be discontinued at any time.

In order to comply with the securities laws of certain states, if applicable, the securities must be sold in such jurisdictions only through registered or licensed brokers or dealers. In addition, in certain states the securities may not be sold unless they have been registered or qualified for sale in the applicable state or an exemption from the registration or qualification requirement is available and is complied with.

Rule 15c6-1 under the Exchange Act generally requires that trades in the secondary market settle in one business day unless the parties to any such trade expressly agree otherwise. Your prospectus supplement may

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provide that the original issue date for your securities may be more than one scheduled business day after the trade date for your securities. Accordingly, in such a case, if you wish to trade securities on any date prior to the first business day before the original issue date for your securities, you will be required, by virtue of the fact that your securities initially are expected to settle in more than one scheduled business day after the trade date for your securities, to make alternative settlement arrangements to prevent a failed settlement.

This prospectus, any applicable prospectus supplement and any applicable pricing supplement in electronic format may be made available on the Internet sites of, or through other online services maintained by, us and/or one or more of the agents and/or dealers participating in an offering of securities, or by their affiliates. In those cases, prospective investors may be able to view offering terms online and, depending upon the particular agent or dealer, prospective investors may be allowed to place orders online.

Other than this prospectus, any applicable prospectus supplement and any applicable pricing supplement in electronic format, the information on our website or the website of any agent or dealer, and any information contained in any other website maintained by any agent or dealer:

• is not part of this prospectus, any applicable prospectus supplement or any applicable pricing supplement or the registration statement of which they form a part;

• has not been approved or endorsed by us or by any agent or dealer in its capacity as an agent or dealer, except, in each case, with respect to the respective website maintained by such entity; and

• should not be relied upon by investors.

There can be no assurance that we will sell all or any of the securities offered by this prospectus.

This prospectus may also be used in connection with any issuance of common stock or preferred stock upon exercise of a warrant if such issuance is not exempt from the registration requirements of the Securities Act.

In addition, we may issue the securities as a dividend or distribution or in a subscription rights offering to our existing securityholders. In some cases, we or dealers acting with us or on our behalf may also purchase securities and reoffer them to the public by one or more of the methods described above. This prospectus may be used in connection with any offering of our securities through any of these methods or other methods described in the applicable prospectus supplement.

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LEGAL MATTERS

Unless otherwise indicated in the applicable prospectus supplement, the validity of the securities offered hereby will be passed upon for us by Lowenstein Sandler LLP, New York, New York. If the validity of the securities offered hereby in connection with offerings made pursuant to this prospectus are passed upon by counsel for the underwriters, dealers or agents, if any, such counsel will be named in the prospectus supplement relating to such offering.

EXPERTS

The financial statements of Coya Therapeutics, Inc. as of December 31, 2024 and 2023 and the related consolidated statements of operations and comprehensive loss, stockholders’ equity and cash flows for each of the years then ended, have been audited by Weaver and Tidwell, L.L.P., an independent registered public accounting firm as stated in their report, which is incorporated herein by reference, which expresses an unqualified opinion on the financial statements. Such financial statements have been incorporated herein by reference in reliance on the reports of such firm, given upon their authority as experts in auditing and accounting.

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ADDITIONAL INFORMATION

This prospectus is part of a registration statement on Form S-3 that we have filed with the SEC relating to our securities being offered hereby. This prospectus does not contain all of the information in the registration statement and its exhibits. The registration statement, its exhibits and the documents incorporated by reference in this prospectus and their exhibits, all contain information that is material to the offering of the securities hereby. Whenever a reference is made in this prospectus to any of our contracts or other documents, the reference may not be complete. You should refer to the exhibits that are a part of the registration statement in order to review a copy of the contract or documents.

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet on the SEC’s website at http://www.sec.gov. Additionally, you may access our filings with the SEC through our website at http://www.coyatherapeutics.com. We have included our website address as an inactive textual reference only and our website and the information contained on, or that can be accessed through, our website will not be deemed to be incorporated by reference in, and are not considered part of this prospectus.

We will provide you without charge, upon your oral or written request, with an electronic or paper copy of any or all reports, proxy statements and other documents we file with the SEC, as well as any or all of the documents incorporated by reference in this prospectus (other than exhibits to such documents unless such exhibits are specifically incorporated by reference into such documents). Requests for such copies should be directed to:

Coya Therapeutics, Inc.

5850 San Felipe St., Suite 500

Houston, Texas 77057

(800) 587-8170

You should rely only on the information in this prospectus and the additional information described above and under the heading “Incorporation of Certain Information by Reference” below. We have not authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely upon it. We are not making an offer to sell these securities in any jurisdiction where such offer or sale is not permitted. You should assume that the information in this prospectus was accurate on the date of the front cover of this prospectus only. Our business, financial condition, results of operations and prospects may have changed since that date.

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INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to “incorporate by reference” information that we file with it into this prospectus, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is an important part of this prospectus. The information incorporated by reference is considered to be a part of this prospectus, and information that we file later with the SEC will automatically update and supersede information contained in this prospectus and any accompanying prospectus supplement.

We incorporate by reference the documents listed below that we have previously filed with the SEC:

• Our Annual Report on Form 10-K for the fiscal year ended December 31, 2024, filed with the SEC on March  18, 2025, as amended on our Form 10-K/A, filed with the SEC on April 28, 2025;

• Our Quarterly Reports on Form 10-Q for the quarterly period ended March 31, 2025, filed with the SEC on May 13, 2025, and the quarterly period ended June 30, 2025, filed with the SEC on August 12, 2025;

• Our Current Reports on Form 8-K filed with the SEC on June  26, 2025, July  1, 2025, and July 29, 2025 (other than any portions thereof deemed furnished and not filed); and

• The description of our common stock, par value $0.0001 per share, contained in our Form 8-A filed on December  27, 2022, including any amendment or report filed for the purpose of updating such description, including the Description of Securities filed as Exhibit 4.7 to our Annual Report on Form 10-K for the year ended December  31, 2023, filed with the SEC on March 19, 2024.

All reports and other documents that we file with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of the initial registration statement and prior to effectiveness of the registration statement, and after the date of this prospectus until the termination or completion of the offering of the securities hereunder will also be considered to be incorporated by reference into this prospectus from the date of the filing of these reports and documents, and will supersede the information herein; provided, however, that all reports, exhibits and other information that we “furnish” to the SEC will not be considered incorporated by reference into this prospectus. We undertake to provide without charge to each person (including any beneficial owner) who receives a copy of this prospectus, upon written or oral request, a copy of all of the preceding documents that are incorporated by reference (other than exhibits, unless the exhibits are specifically incorporated by reference into these documents). You may request a copy of these materials in the manner set forth under the heading “Additional Information,” above.

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$75,000,000

Common Stock

Preferred Stock

Warrants

Debt Securities

Subscription Rights

Units

PROSPECTUS

August 19, 2025

FAQ

What preclinical efficacy did Coya (COYA) report for COYA 303?

The company reported COYA 303 produced a 42% increase in Treg suppressive function (p < 0.001) compared to single agents and reduced BAX transcript levels (p < 0.01).

Has Coya filed for clinical studies for COYA 302?

Yes. Coya re-submitted an IND on June 30, 2025 that includes requested data to support a planned Phase 2 randomized, double-blind, placebo-controlled 24-week study with a 24-week open-label extension in ALS.

What are Coya’s recent financial results?

Coya reported net losses of $13.4 million and $7.9 million for the six months ended June 30, 2025 and 2024, respectively, and an accumulated deficit of $54.1 million as of June 30, 2025.

What is the therapeutic approach of Coya’s lead programs?

Coya develops combination biologics built on low-dose IL-2 (LD IL-2) to enhance regulatory T cell (Treg) function and survival, combining LD IL-2 with agents such as GLP-1 receptor agonists and CTLA4-Ig.

What clinical indication is targeted by the planned Phase 2 study?

The planned Phase 2 study of COYA 302 targets Amyotrophic Lateral Sclerosis (ALS).