SEC Form S-3ASR filed by Celcuity Inc.

As filed with the Securities and Exchange Commission on January 9, 2026

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

CELCUITY INC.

(Exact name of registrant as specified in its charter)

16305 36th Avenue North, Suite 100

Minneapolis, Minnesota 55446
(763) 392-0767
(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Brian F. Sullivan
Chief Executive Officer
16305 36th Avenue North, Suite 100

Minneapolis, Minnesota 55446
(763) 392-0767
(Name, address, including zip code, and telephone number, including area code, of agent for service)

Please send copies of all communications to:

Approximate date of commencement of proposed sale to the public: From time to time after the effectiveness of the Registration Statement.

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

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

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

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

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

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

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

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

EXPLANATORY NOTE

This registration statement contains:

The base prospectus immediately follows this explanatory note. The specific terms of any securities to be offered pursuant to the base prospectus will be specified in a prospectus supplement to the base prospectus. The sales agreement prospectus supplement immediately follows the base prospectus.

PROSPECTUS

CELCUITY INC.

Common Stock
Preferred Stock
Warrants
Debt Securities
Units

The securities covered by this prospectus may include shares of our common stock; shares of preferred stock; warrants to purchase shares of our common stock, preferred stock and/or debt securities; debt securities consisting of debentures, notes or other evidences of indebtedness; or units consisting of any combination of such securities. We may offer the securities from time to time in one or more series or issuances directly to our stockholders or purchasers, or through agents, underwriters or dealers as designated from time to time.

This prospectus provides a general description of the securities we may offer. Each time we sell securities, we will provide specific terms of the securities offered in a supplement to this prospectus. Such a prospectus supplement may also add, update or change information contained in this prospectus. This prospectus may not be used to consummate a sale of securities unless accompanied by the applicable prospectus supplement. We will sell these securities directly to our stockholders or to 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.

Our common stock is traded on The Nasdaq Capital Market under the symbol “CELC.” On January 6, 2026, the closing price of our common stock was $105.02.

Investing in our securities involves risks. See “Risk Factors” on page 5. You should carefully read this prospectus, the documents incorporated herein, and the applicable prospectus supplement before making any investment decision.

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

The date of this prospectus is January 9, 2026.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

This prospectus is part of an automatic shelf registration statement that we filed with the Securities and Exchange Commission (the “SEC”) as a “well-known seasoned issuer” as defined in Rule 405 under the Securities Act of 1933, as amended (the “Securities Act”), using a “shelf” registration process. Under this shelf registration process, we may offer to sell any combination of the securities described in this prospectus in one or more offerings. No limit exists on the aggregate number or amount of securities we may sell pursuant to the registration statement of which this prospectus is a part. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities under this shelf registration, we will provide a prospectus supplement that will contain specific information about the terms of such offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement or any related free writing prospectus may also add, update or change information contained in this prospectus with respect to that offering. If there is any inconsistency between the information in this prospectus and the applicable prospectus supplement or any free writing prospectus, you should rely on the prospectus supplement or free writing prospectus, as applicable. You should read both this prospectus and any applicable prospectus supplement (and any related free writing prospectuses), including all documents incorporated herein by reference, together with additional information described under “Where You Can Find More Information” below.

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

This prospectus incorporates by reference, and any prospectus supplement or related free writing prospectus may contain and incorporate by reference, market data and industry statistics and forecasts that are based on independent industry publications and other publicly available information. Although we believe these sources are reliable, we do not guarantee the accuracy or completeness of this information and we have not independently verified this information. In addition, the market and industry data and forecasts that may be included or incorporated by reference in this prospectus, any prospectus supplement or any related free writing prospectus may involve estimates, assumptions and other risks and uncertainties and are subject to change based on various factors, including those discussed under the heading “Risk Factors” contained in this prospectus, the applicable prospectus supplement and any related free writing prospectus, and under similar headings in other documents that are incorporated by reference into this prospectus.

We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference in this prospectus were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs. Accordingly, investors should not place undue reliance on this information.

Unless the context otherwise requires, “CELC,” the “Company,” “we,” “us,” “our” and similar names refer to Celcuity Inc. When we refer to “you,” we mean the potential holders of the applicable series of securities.

RISK FACTORS

Investing in our securities involves risk. You should consider the risks, uncertainties and assumptions discussed under the heading “Risk Factors” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2024 filed on March 31, 2025 with the SEC, which is incorporated herein by reference, and may be amended, supplemented or superseded from time to time by other reports we file with the SEC in the future. See “Where You Can Find More Information” and “Incorporation of Certain Documents by Reference.” The risks and uncertainties we have described are not the only ones we face. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also affect our operations. If any of these risks were to occur, our business, financial condition, and results of operations could be severely harmed. This could cause the trading price of our common stock to decline, and you could lose all or part of your investment.

In addition, any prospectus supplement applicable to each offering of our securities will contain a discussion of the risks applicable to such an investment in us. Prior to making a decision about investing in our securities, you should carefully consider the specific factors discussed under the heading “Risk Factors” in the applicable prospectus supplement, together with all of the other information contained or incorporated by reference in such prospectus supplement or appearing or incorporated by reference in this prospectus.

SPECIAL NOTE ABOUT FORWARD-LOOKING STATEMENTS

The Private Securities Litigation Reform Act of 1995 provides a “safe harbor” for forward-looking statements. This prospectus, any prospectus supplement and the documents incorporated herein by reference contain forward-looking statements regarding us, our business prospects and our results of operations that are subject to certain risks and uncertainties that could cause our actual business, prospects and results of operations to differ materially from those that may be anticipated by such forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, those described under “Risk Factors” herein and in our other filings with the SEC. You should not place undue reliance on these forward-looking statements, which speak only as of the date such forward-looking statement is made. We expressly disclaim any intent or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. You are urged to carefully review and consider the various disclosures made by us in this prospectus, any prospectus supplement and the documents incorporated herein by reference and in our other reports filed with the SEC that advise interested parties of the risks and uncertainties that may affect our business.

All statements, other than statements of historical facts, contained in this prospectus, any prospectus supplement and the documents incorporated herein by reference, including statements regarding our plans, objectives and expectations for our business, operations and financial performance and condition, are forward-looking statements. In some cases, you can identify forward-looking statements by the following words: “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “might,” “ongoing,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “will,” “would,” or the negative of these terms or other comparable terminology, although not all forward-looking statements contain these words. Forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause our results, performance or achievements to be materially different from the information expressed or implied by the forward-looking statements in this prospectus, any prospectus supplement and the documents incorporated herein by reference. Additionally, our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments that we may make. Forward-looking statements may include, among other things, statements relating to:

These statements involve known and unknown risks, uncertainties and other factors that may cause our results or our industry’s actual results, levels of activity, performance or achievements to be materially different from the information expressed or implied by these forward-looking statements. Certain risks, uncertainties and other factors include, but are not limited to, our limited operating history; our potential inability to develop, validate, obtain regulatory approval for and commercialize gedatolisib on a timely basis or at all; the uncertainties and costs associated with clinical studies and with developing and commercializing biopharmaceuticals; the complexity and difficulty of demonstrating the safety and sufficient magnitude of benefit to support regulatory approval of gedatolisib and other products we may develop; challenges we may face in developing and maintaining relationships with pharmaceutical company partners, including our current and any future suppliers of our product candidate; the uncertainty and costs associated with clinical trials; the uncertainty regarding market acceptance by physicians, patients, third-party payors and others in the medical community, and with the size of market opportunities available to us; difficulties we may face in managing growth, such as hiring and retaining a qualified sales force and attracting and retaining key personnel; changes in government regulations; tightening credit markets and limitations on access to capital; stock market volatility or other factors that may affect our ability to access capital on favorable terms or at all; and obtaining and maintaining intellectual property protection for gedatolisib and time and expense associated with defending third-party claims of intellectual property infringement, investigations or litigation threatened or initiated against us. See “Risk Factors” beginning on page 5 of this prospectus for additional risks, uncertainties and other factors applicable to us.

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

USE OF PROCEEDS

Except as otherwise provided in the applicable prospectus supplement, we intend to use the net proceeds from the sale of the securities covered by this prospectus for working capital and general corporate purposes. General corporate purposes may include clinical trial expenditures, commercial launch expenditures (including sales, marketing and reimbursement functions), research and development expenditures, capital expenditures, expansion of business development activities and other general corporate purposes. We may also use a portion of our net proceeds for the potential acquisition of businesses, technologies and products, although we have no current binding understandings, commitments or agreements to do so. Additional information on the use of net proceeds from the sale of securities covered by this prospectus may be set forth in any prospectus supplement relating to the specific offering.

The amounts and timing of our expenditures will depend on numerous factors, including the status, results and timing of our current and expected clinical trials involving gedatolisib and other corporate developments. Accordingly, our management will have broad discretion over the use of the net proceeds from the sale of any securities offered by us.

PLAN OF DISTRIBUTION

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

We may also sell securities covered by this prospectus in an “at the market offering” as defined in Rule 415 under the Securities Act. Such at the market offerings, if any, may be conducted by underwriters acting as principal or agent. Such offering may be made into an existing trading market for such securities in transactions at other than a fixed price, either:

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

If underwriters are used in the sale, the underwriters will acquire the securities for their own account, including through underwriting, purchase, security lending or repurchase agreements with us. Only underwriters named in the prospectus supplement are underwriters of the securities offered by the prospectus supplement. The underwriters may resell the securities from time to time in one or more transactions, including negotiated transactions. Underwriters may sell the securities in order to facilitate transactions in any of our other securities (described in this prospectus or otherwise), including other public or private transactions and short sales. Underwriters may offer securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters. Unless otherwise indicated in the prospectus supplement, the obligations of the underwriters to purchase the securities will be subject to certain conditions, and the underwriters will be obligated to purchase all the offered securities if they purchase any of them. Any public offering price and any discounts or concessions allowed or reallowed or paid to dealers may change from time to time. The prospectus supplement will include the names of the principal underwriters, the respective amount of securities underwritten, the nature of the obligation of the underwriters to take the securities and the nature of any material relationship between an underwriter and us.

If dealers are used in the sale of securities offered through this prospectus, we will sell the securities to them as principals. They may then resell those securities to the public at varying prices determined by the dealers at the time of resale. The prospectus supplement will include the names of the dealers and the terms of the transaction.

We may sell the securities offered through this prospectus directly. In this case, no underwriters or agents would be involved. Such securities may also be sold through agents designated from time to time. The prospectus supplement will name any agent involved in the offer or sale of the offered securities and will describe any commissions payable to the agent by us. Unless otherwise indicated in the prospectus supplement, any agent will agree to use its reasonable best efforts to solicit purchases for the period of its appointment.

Dealers and agents participating in the distribution of the securities may be deemed to be underwriters, and compensation received by them on resale of the securities may be deemed to be underwriting discounts. If such dealers or agents were deemed to be underwriters, they may be subject to statutory liabilities under the Securities Act.

We may sell the securities directly to institutional investors or others who may be deemed to be underwriters within the meaning of the Securities Act with respect to any sale of those securities. The terms of any such sales will be described in the prospectus supplement.

If the prospectus supplement indicates, we may authorize agents, underwriters or dealers to solicit offers from certain types of institutions to purchase securities at the public offering price under delayed delivery contracts. These contracts would provide for payment and delivery on a specified date in the future. The contracts would be subject only to those conditions described in the prospectus supplement. The applicable prospectus supplement will describe the commission payable for solicitation of those contracts.

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

Unless the applicable prospectus supplement states otherwise, each series of securities offered by us will be a new issue and will have no established trading market, other than our common stock, which is listed on The Nasdaq Capital Market. We may elect to list any series of offered securities on an exchange. Any underwriters that we use in the sale of offered securities may make a market in such securities, but may discontinue such market making at any time without notice. Therefore, we cannot assure you that the securities will have a liquid trading market.

Any underwriter may also engage in stabilizing transactions, syndicate covering transactions and penalty bids in accordance with Rule 104 under the Exchange Act. Stabilizing transactions involve bids to purchase the underlying security in the open market for the purpose of pegging, fixing or maintaining the price of the securities. Syndicate covering transactions involve purchases of the securities in the open market after the distribution has been completed in order to cover syndicate short positions. Penalty bids permit the underwriters to reclaim a selling concession from a syndicate member when the securities originally sold by the syndicate member are purchased in a syndicate covering transaction to cover syndicate short positions. Stabilizing transactions, syndicate covering transactions and penalty bids may cause the price of the securities to be higher than it would be in the absence of the transactions. The underwriters may, if they commence these transactions, discontinue them at any time.

We, the underwriters or other agents may engage in derivative transactions involving the securities. These derivatives may consist of short sale transactions and other hedging activities. The underwriters or agents may acquire a long or short position in the securities, hold or resell securities acquired and purchase options or futures on the securities and other derivative instruments with returns linked to or related to changes in the price of the securities. In order to facilitate these derivative transactions, we may enter into security lending or repurchase agreements with the underwriters or agents. The underwriters or agents may effect the derivative transactions through sales of the securities to the public, including short sales, or by lending the securities in order to facilitate short sale transactions by others. The underwriters or agents may also use the securities purchased or borrowed from us or others (or, in the case of derivatives, securities received from us in settlement of those derivatives) to directly or indirectly settle sales of the securities or close out any related open borrowings of the securities.

DESCRIPTION OF CAPITAL STOCK

The following summary of the terms of our capital stock is subject to and qualified in its entirety by reference to applicable Delaware law, our certificate of incorporation and bylaws, copies of which are filed as Exhibits 3.1 and 3.2, respectively, to the registration statement of which this prospectus forms a part and are incorporated herein by reference. Please refer to “Where You Can Find More Information” below for directions on obtaining these documents.

Our authorized capital consists of:

Common Stock

Fully Paid and Nonassessable

The outstanding shares of our common stock are duly authorized, fully paid and nonassessable.

Voting Rights

Each holder of common stock is entitled to one vote for each share on all matters submitted to a vote of the stockholders.

Dividend Rights

Holders of our common stock are entitled to receive ratably any dividends that our board of directors may declare out of funds legally available for that purpose.

Rights and Preferences

Holders of our common stock have no preemptive, conversion, subscription or other rights, and there are no redemption or sinking fund provisions applicable to our common stock.

Right to Liquidation Distributions

Upon our liquidation, dissolution or winding-up, the assets legally available for distribution to our stockholders would be distributable ratably among the holders of our common stock and any participating preferred stock outstanding at that time, subject to prior satisfaction of all outstanding debt and liabilities and the preferential rights of and the payment of liquidation preferences, if any, on any outstanding shares of preferred stock, including the liquidation preference of our Series A Preferred Stock.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Continental Stock Transfer & Trust Company. The transfer agent and registrar’s address is One State Street, 30th Floor, New York, NY 10004.

The Nasdaq Capital Market

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

Preferred Stock

Our board of directors is authorized, without action by the stockholders, to designate and issue up to an aggregate of 2,500,000 shares of preferred stock in one or more series. Our board of directors is authorized to designate the rights, preferences and privileges of the shares of each series and any of its qualifications, limitations or restrictions. Our board of directors is able to authorize the issuance of preferred stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of common stock. The issuance of preferred stock, while providing flexibility in connection with possible future financings and acquisitions and other corporate purposes, could, under certain circumstances, have the effect of restricting dividends on our common stock, diluting the voting power of our common stock, impairing the liquidation rights of our common stock, or delaying, deferring or preventing a change in control of us, which might harm the market price of our common stock. See also “Anti-Takeover Effect of Delaware Law and Certain Charter and Bylaw Provisions” below.

On May 16, 2022, in connection with a Securities Purchase Agreement, dated May 15, 2022, by and among us and the Investors named therein (the “2022 Investors,” and such Securities Purchase Agreement, the “2022 Securities Purchase Agreement”), we filed a Certificate of Designations (the “Certificate of Designations”) with the Secretary of State of the State of Delaware, designating 1,850,000 shares out of the authorized but unissued shares of its preferred stock as Series A Convertible Preferred Stock. The following is a summary of the principal terms of the Series A Preferred Stock:

Dividend Rights

Holders of Series A Preferred Stock shall be entitled to receive dividends or distributions on shares of Series A Preferred Stock equal (on an as-if-converted-to-common stock basis) to and in the same form as dividends or distributions actually paid on shares of the common stock when, as and if such dividends or distributions are paid on shares of the common stock. No other dividends or distributions shall be paid on shares of Series A Preferred Stock.

Right to Liquidation Distributions

In the event of any voluntary or involuntary liquidation, dissolution or winding up of us, the holders of shares of Series A Preferred Stock then outstanding shall be entitled to be paid out of the assets of us available for distribution to its stockholders, and in the event of a Deemed Liquidation Event (as defined in the Certificate of Designations), the holders of shares of Series A Preferred Stock then outstanding shall be entitled to be paid out of the consideration payable to stockholders in such Deemed Liquidation Event or out of the Available Proceeds (as defined in the Certificate of Designations), as applicable, before any payment shall be made to the holders of common stock by reason of their ownership thereof, an amount per share equal to the greater of (i) the Series A Original Issue Price (as defined in the Certificate of Designations), plus any dividends declared but unpaid thereon, or (ii) such amount per share as would have been payable had all shares of Series A Preferred Stock been converted into common stock pursuant to the Certificate of Designations immediately prior to such liquidation, dissolution, winding up or Deemed Liquidation Event.

Voting Rights

The Series A Preferred Stock is non-voting stock and does not entitle the holder thereof to vote on any matter submitted to our stockholders for their action or consideration, except as otherwise provided by the General Corporation Law of the State of Delaware (the “DGCL”) or the other provisions of the certificate of incorporation or the Certificate of Designations.

As long as any shares of Series A Preferred Stock are outstanding, we may not, without the approval of the holders of a majority of the outstanding shares of Series A Preferred Stock, take the following actions: (i) amend, alter or repeal any provision of our certificate of incorporation, our Certificate of Designations or our bylaws in a manner that adversely affects the powers, preferences or rights of the Series A Preferred Stock; (ii) create, or authorize the creation of, or issue or obligate itself to issue shares of, any additional class or series of capital stock unless the same ranks junior to the Series A Preferred Stock with respect to the distribution of assets on the liquidation, dissolution or winding up of us, the payment of dividends and the rights of redemption, or increase the authorized number of shares of Series A Preferred Stock or increase the authorized number of shares of any additional class or series of our capital stock unless the same ranks junior to the Series A Preferred Stock with respect to the distribution of assets on the liquidation, dissolution or winding up of us, the payment of dividends and the rights of redemption; (iii) (A) reclassify, alter or amend any existing security of us that is pari passu with the Series A Preferred Stock in respect of the distribution of assets on the liquidation, dissolution or winding up of us, the payment of dividends or the rights of redemption, if such reclassification, alteration or amendment would render such other security senior to the Series A Preferred Stock in respect of any such right, preference, or privilege or (B) reclassify, alter or amend any existing security of us that is junior to the Series A Preferred Stock in respect of the distribution of assets on the liquidation, dissolution or winding up of us, the payment of dividends or the rights of redemption, if such reclassification, alteration or amendment would render such other security senior to or pari passu with the Series A Preferred Stock in respect of any such right, preference or privilege; or (iv) purchase or redeem (or permit any subsidiary to purchase or redeem) or pay or declare any dividend or make any distribution on, any shares of capital stock of us (with exceptions for (i) redemptions of or dividends or distributions on the Series A Preferred Stock as expressly authorized in the Certificate of Designations, and (ii) dividends or other distributions payable on our common stock solely in the form of additional shares of common stock).

Conversion Rights

Subject to the Beneficial Ownership Limitation described below, each share of Series A Preferred Stock shall be convertible, at the option of the holder thereof, at any time and from time to time, and without the payment of additional consideration by the holder thereof, into such number of fully paid and non-assessable shares of common stock as is determined by multiplying one share of Series A Preferred Stock by the Series A Conversion Rate in effect at the time of conversion. The “Series A Conversion Rate” shall initially be ten (10) shares of Common Stock for each share of Series A Preferred Stock. The Series A Conversion Rate shall be subject to adjustment as provided in the Certificate of Designations.

Under the terms of the Certificate of Designations, we may not effect the conversion of Series A Preferred Stock into common stock, and a holder will not be entitled to request the conversion of shares of Series A Preferred Stock, if, upon giving effect to such conversion, the aggregate number of shares of common stock beneficially owned by the holder (together with its affiliates, any other persons acting as a group together with the holder or any of the holder’s affiliates, and any other persons whose beneficial ownership of common stock would or could be aggregated with the holder’s for purposes of Section 13(d) or Section 16 of the Exchange Act) would exceed the Beneficial Ownership Limitation, which is 9.9% of the number of shares of common stock outstanding immediately after giving effect to the conversion, as such percentage ownership is calculated in accordance with Section 13(d) of the Exchange Act and the applicable regulations of the SEC. A holder may reset the Beneficial Ownership Limitation percentage to a higher percentage (not to exceed 19.9%), effective 61 days after written notice to us, or a lower percentage, effective immediately upon written notice to us. Any such increase or decrease will apply only to that holder and not to any other holder of Series A Preferred Stock.

The Series A Preferred Stock does not have, nor is it subject to, any preemptive or similar rights.

Transfer Agent and Registrar

The transfer agent and registrar for any series or class of preferred stock will be set forth in each applicable prospectus supplement.

Warrants

2025 Warrants

On September 9, 2025, we entered into the Third Amendment to Amended and Restated Loan and Security Agreement, dated as of September 9, 2025, by and among us, Oxford Finance LLC (“Oxford”), as collateral agent, and the Lenders named therein, including Oxford in its capacity as a Lender and Innovatus Life Sciences Lending Fund I, LP (“Innovatus”) (the “Third Amendment” and the existing Amended and Restated Loan and Security Agreement, the “A&R Loan Agreement”), pursuant to which the A&R Loan Agreement was amended to (i) replace Innovatus with Oxford as collateral agent; (ii) recognize the achievement of the Term D Milestone (as defined in the A&R Loan Agreement, as amended by the Third Amendment (the “Amended A&R Loan Agreement”)) and provide for the immediate disbursement of the $30.0 million Term D Loan (as defined in the Amended A&R Loan Agreement); (iii) increase the size of the Term E Loan (as defined in the Amended A&R Loan Agreement) from $50.0 million to up to $100.0 million, which Term E Loan may only be drawn upon U.S. Food and Drug Administration approval of gedatolisib in second line WT advanced breast cancer patients post CDK4/6 inhibitor therapy; (iv) add three new $40.0 million Term F Loans (as defined in the Amended A&R Loan Agreement), which may only be drawn upon achievement of certain trailing three months’ product revenue thresholds; (v) replace the prior $45.0 million Term F Loan (as defined in the A&R Loan Agreement) with a new $150.0 million Term G Loan (as defined in the Amended A&R Loan Agreement), which continues to be available only in the Lenders’ sole discretion upon our request; (vi) require an amendment fee payable by us to the Lenders in the amount of $50,000, which was paid at the closing of the Third Amendment; (vii) make certain revisions to the non-utilization fee for the Term E Loan, and add a new non-utilization fee for the Term F Loans, in each case equal to 3.0% of the applicable unfunded commitment, after taking into consideration any reductions to the applicable term loan commitment that we may make by notice to the collateral agent before the date that is eight weeks after the achievement of any applicable milestones; and (viii) extend the maturity date of the term loans to November 1, 2029.

In connection with the Third Amendment, we issued warrants to purchase an aggregate of 50,537 shares of our common stock to Innovatus, Oxford, and certain of its affiliates (the “2025 Warrants”). The 2025 Warrants may be exercised on a cashless basis and are exercisable through the tenth anniversary of the funding date of the Term D Loan. The number of shares of common stock for which each 2025 Warrant is exercisable and the associated exercise price are subject to certain proportional adjustments as set forth in such 2025 Warrant.

2025 Pre-Funded Warrants

On July 30, 2025, we entered into an underwriting agreement (the “Underwriting Agreement”) with Jefferies LLC, TD Securities (USA) LLC, and Leerink Partners LLC as representatives of the several underwriters named therein (collectively, the “Underwriters”) agreeing, subject to customary conditions, to issue and sell in a public offering (i) 1,836,842 shares of our common stock at a price to the public of $38.00 per share and (b) in lieu of shares of common stock to certain investors, pre-funded warrants to purchase up to 400,000 shares of common stock (the “2025 Pre-Funded Warrants”), at a price to the public of $37.999 per 2025 Pre-Funded Warrant, which represents the per share public offering price for the shares of common stock less the $0.001 per share exercise price for each such 2025 Pre-Funded Warrant. In addition, pursuant to the Underwriting Agreement, we granted the Underwriters an option to purchase up to an additional 335,526 shares of common stock (the “Option Shares”), less underwriting discounts and commissions. The Underwriters exercised their option to purchase the Option Shares in full on July 30, 2025. The offering was completed on July 31, 2025.

2024 Warrants

In connection with the funding of each of the Term C Loan and the Term D Loan (each as defined in the Amended A&R Loan Agreement), we agreed to issue to Innovatus and Oxford warrants to purchase that number of shares of our common stock equal to 2.5% of the principal amount of the applicable Term Loan (as defined in the Amended A&R Loan Agreement) divided by the exercise price, which was, with respect to the Term C Loan, equal to the lower of (i) the volume weighted average closing price of our common stock for the five-trading day period ending on the last trading day immediately preceding the execution of the A&R Loan Agreement or (ii) the closing price on the last trading day immediately preceding the execution of the A&R Loan Agreement. Accordingly, on May 30, 2024, we issued 103,876 warrants (the “2024 Warrants”) with an exercise price of $14.84 per share. For the Term D Loans, the exercise price was based on the lower of (i) the exercise price for the 2024 Warrants issued pursuant to the Term C Loan or (ii) the volume weighted average closing price of our common stock for the five-trading day period ending on the last trading day immediately preceding the Term D Loan funding. Prior to the Third Amendment, we also were required to issue warrants to Innovatus and Oxford in connection with the funding of the Term E Loan and the Term F Loan. The 2024 Warrants may be exercised on a cashless basis and are exercisable through the tenth anniversary of the applicable funding date. The number of shares of common stock for which each 2024 Warrant is exercisable and the associated exercise price are subject to certain proportional adjustments as set forth in such 2024 Warrant.

2023 Pre-Funded Warrants

Under the Securities Purchase Agreement, dated October 18, 2023, by and among us and the Investors named therein (the “2023 Investors,” and such Securities Purchase Agreement, the “2023 Securities Purchase Agreement”), we issued pre-funded warrants (the “2023 Warrants”) to purchase 5,747,787 shares of common stock. Each 2023 Warrant to purchase one share was sold for a purchase price of $8.699 per 2023 Warrant and has an exercise price of $0.001 per share (for aggregate consideration equating to $8.70 per share of common stock issuable upon exercise of the 2023 Warrants).

Each 2023 Warrant is immediately exercisable and will not expire. Under the terms of the 2023 Warrants, we may not effect the exercise of any such 2023 Warrant, and a holder will not be entitled to exercise any portion of any 2023 Warrant, if, upon giving effect to such exercise, the aggregate number of shares of common stock beneficially owned by the holder (together with its affiliates, other persons acting or who could be deemed to be acting as a group together with the holder or any of the holder’s affiliates, and any other persons whose beneficial ownership of common stock would or could be aggregated with the holder’s or any of the holder’s affiliates for purposes of Section 13(d) or Section 16 of the Exchange Act) would exceed 4.99% of the number of shares of common stock outstanding immediately after giving effect to the exercise, as such percentage ownership is calculated in accordance with Section 13(d) of the Exchange Act and the applicable regulations of the SEC (the “Maximum Percentage”). A holder may reset the Maximum Percentage to a higher percentage (not to exceed 19.99%), effective 61 days after written notice to us, or a lower percentage, effective immediately upon written notice to us. Any such increase or decrease will apply only to that holder and not to any other holder of 2023 Warrants.

Registration Rights Agreement

2023 Registration Rights Agreement

In connection with the 2023 Securities Purchase Agreement, we entered into a Registration Rights Agreement (the “2023 Registration Rights Agreement”) with the 2023 Investors, pursuant to which we agreed to register for resale the Registrable Securities (the “2023 Registrable Securities”), which include: (i) the shares of common stock then issued or issuable upon exercise of the 2023 Warrants (assuming the 2023 Warrants are exercisable in full without regard to any exercise limitation therein) (the “2023 Warrant Shares”), and (ii) any other securities issued or issuable with respect to, in exchange for or in replacement of, the 2023 Warrant Shares issued and sold pursuant to the 2023 Securities Purchase Agreement. Under the 2023 Registration Rights Agreement, we agreed to file a registration statement covering the resale by the 2023 Investors of the 2023 Registrable Securities no later than 30 days following the Closing Date (as defined in the 2023 Registration Rights Agreement). We agreed to use commercially reasonable efforts to cause the registration statement to become effective and to keep such registration statement effective until such time as there are no longer 2023 Registrable Securities held by the 2023 Investors. We agreed to be responsible for all fees and expenses incurred in connection with the registration of the 2023 Registrable Securities. We filed a registration statement on Form S-3 registering for resale the 2023 Registrable Securities, which was declared effective on November 28, 2023.

We granted the 2023 Investors customary indemnification rights in connection with the registration statement, including for liabilities arising under the Securities Act. The 2023 Investors also granted us customary indemnification rights in connection with the registration statement.

2022 Registration Rights Agreement

In connection with the 2022 Securities Purchase Agreement, we entered into a Registration Rights Agreement (the “2022 Registration Rights Agreement”) with the 2022 Investors, pursuant to which we agreed to register for resale the Registrable Securities (the “2022 Registrable Securities”), which include: (i) the common stock, (ii) the shares of common stock then issued or issuable upon conversion of the Series A Preferred Stock (assuming on such date the shares of Series A Preferred Stock are convertible in full without regard to any conversion limitations in the Certificate of Designations), and (iii) the common stock then issued or issuable upon exercise of the warrants issued pursuant to the 2022 Securities Purchase Agreement (assuming such warrants were exercisable in full without regard to any exercise limitations therein). Under the 2022 Registration Rights Agreement, we agreed to file a registration statement covering the resale by the 2022 Investors of the 2022 Registrable Securities no later than 30 days following (i) the Closing Date (as defined in the 2022 Registration Rights Agreement) and (ii) the date we obtained the necessary stockholder approval to effect the Authorized Share Increase. We agreed to use commercially reasonable efforts to cause the registration statement to become effective and to keep such registration statement effective until such time as there are no longer 2022 Registrable Securities held by the 2022 Investors. We agreed to be responsible for all fees and expenses incurred in connection with the registration of the 2022 Registrable Securities. We filed a registration statement on Form S-3 registering for resale the 2022 Registrable Securities, which was declared effective on January 11, 2023.

We granted the 2022 Investors customary indemnification rights in connection with the registration statement, including for liabilities arising under the Securities Act. The 2022 Investors also granted us customary indemnification rights in connection with the registration statement.

The representations, warranties and covenants contained in each of the Amended A&R Loan Agreement, the 2025 Pre-Funded Warrants, the 2023 Warrants, the 2023 Securities Purchase Agreement, the 2022 Securities Purchase Agreement, the 2023 Registration Rights Agreement and the 2022 Registration Rights Agreement were made solely for the benefit of the parties thereto and may be subject to limitations agreed upon by the contracting parties.

Anti-Takeover Effect of Delaware Law and Certain Charter and Bylaw Provisions

Our certificate of incorporation and bylaws contain provisions that could have the effect of discouraging potential acquisition proposals or tender offers or delaying or preventing a change of control of our Company. A summary of these provisions is as follows:

We are subject to the provisions of Section 203 of the DGCL, an anti-takeover law. In general, Section 203 prohibits a publicly held Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a period of three years after the date of the transaction in which the person became an interested stockholder, unless the business combination is approved in a prescribed manner. For purposes of Section 203, a “business combination” includes a merger, asset sale or other transaction resulting in a financial benefit to the interested stockholder, and an “interested stockholder” is a person who owns 15% or more of the voting stock of a corporation, or any affiliate or associate of a corporation who, within three years prior, did own 15% or more of the voting stock of that corporation.

DESCRIPTION OF WARRANTS

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

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

Each warrant will entitle its holder to purchase the principal amount of debt securities or the number of shares of preferred stock or common stock at the exercise price set forth in, or calculable as set forth in, the applicable prospectus supplement. Unless we otherwise specify in the applicable prospectus supplement, holders of the warrants may exercise the warrants at any time up to the specified time on the expiration date that we set forth in the applicable prospectus supplement. After the close of business on the expiration date, unexercised warrants will become void.

A holder of warrant certificates may exchange them for new warrant certificates of different denominations, present them for registration of transfer and exercise them at the corporate office of the transfer agent or any other office indicated in the applicable prospectus supplement. Until any warrants to purchase debt securities are exercised, the holder of the warrants will not have any rights of holders of the debt securities that can be purchased upon exercise, including any rights to receive payments of principal, premium or interest on the underlying debt securities or to enforce covenants in the applicable indenture. Until any warrants to purchase common stock or preferred stock are exercised, the holders of the warrants will not have any rights of holders of the underlying common stock or preferred stock, including any rights to receive dividends or payments upon any liquidation, dissolution or winding up on the common stock or preferred stock, if any.

Transfer Agent and Registrar

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

DESCRIPTION OF DEBT SECURITIES

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

We will issue the debt securities under that certain Indenture, dated as of August 1, 2025, between us and U.S. Bank Trust Company, National Association, as trustee, which has been qualified under the Trust Indenture Act. We have filed this indenture as an exhibit to the registration statement of which this prospectus is a part, and supplemental indentures and forms of debt securities containing the terms of the debt securities being offered will be filed as exhibits to the registration statement of which this prospectus is a part or will be incorporated by reference from reports that we file with the SEC.

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

General

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

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

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

Conversion or Exchange Rights

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

Consolidation, Merger or Sale

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

Events of Default under the Indenture

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

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

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

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

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

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

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

Modification of Indenture; Waiver

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

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

Discharge

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

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

Form, Exchange and Transfer

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

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

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

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

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

Information Concerning the Trustee

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

Payment and Paying Agents

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

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

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

Governing Law

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

DESCRIPTION OF UNITS

We may issue units consisting of any combination of the other types of securities offered under this prospectus in one or more series. We may evidence each series of units by unit certificates that we will issue under a separate agreement. We may enter into unit agreements with a unit agent. Each unit agent will be a bank or trust company that we select. We will indicate the name and address of the unit agent in the applicable prospectus supplement relating to a particular series of units.

The following description, together with the additional information included in any applicable prospectus supplement, summarizes the general features of the units that we may offer under this prospectus. You should read any prospectus supplement and any free writing prospectus that we may authorize to be provided to you related to the series of units being offered, as well as the complete unit agreements that contain the terms of the units. Specific unit agreements will contain additional important terms and provisions and we will file as an exhibit to the registration statement of which this prospectus is a part, or will incorporate by reference from another report that we file with the SEC, the form of each unit agreement relating to units offered under this prospectus.

If we offer any units, certain terms of that series of units will be described in the applicable prospectus supplement, including, without limitation, the following, as applicable:

LEGAL OWNERSHIP OF SECURITIES

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

Book-Entry Holders

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

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

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

Street Name Holders

We may terminate a global security or issue securities in non-global form. In these cases, investors may choose to hold their securities in their own names or in “street name.” Securities held by an investor in street name would be registered in the name of a bank, broker or other financial institution that the investor chooses, and the investor would hold only a beneficial interest in those securities through an account he or she maintains at that institution.

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

Legal Holders

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

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

Special Considerations for Indirect Holders

If you hold securities through a bank, broker or other financial institution, either in book-entry form or in street name, you should check with your own institution to find out:

Global Securities

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

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

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

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

Special Considerations for Global Securities

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

If securities are issued only in the form of a global security, an investor should be aware of the following:

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

Special Situations When a Global Security Will Be Terminated

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

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

The applicable prospectus supplement may also list additional situations for terminating a global security that would apply only to the particular series of securities covered by the applicable prospectus supplement. When a global security terminates, the depositary, and not we or any applicable trustee, is responsible for deciding the names of the institutions that will be the initial direct holders.

WHERE YOU CAN FIND MORE INFORMATION

We have filed with the SEC a registration statement on Form S-3 (the “Registration Statement,” which term shall encompass all amendments, exhibits, annexes and schedules thereto and all documents incorporated by reference therein) pursuant to the Securities Act, and the rules and regulations promulgated thereunder, with respect to the securities offered hereby. This prospectus, which constitutes a part of the Registration Statement, does not contain all the information contained in the Registration Statement, parts of which are omitted in accordance with the rules and regulations of the SEC. For further information with respect to us and the securities offered hereby, reference is made to the Registration Statement.

We are required to file annual and quarterly reports, special reports, proxy statements, and other information with the SEC. The SEC maintains a website that contains reports, proxy and information statements and other information regarding issuers, including us, that file electronically with the SEC. You may obtain documents that we file with the SEC at http://www.sec.gov. We also make these documents publicly available, free of charge, on our website at www.celcuity.com as soon as reasonably practicable after filing such documents with the SEC. Please note, however, that information on, or accessible through, our website is not, and should not be deemed to be, a part of this prospectus and should not be relied upon in connection with making any investment decision with respect to the offered securities.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

The SEC allows us to “incorporate by reference” into this prospectus the information we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus, and information in documents that we file later with the SEC will automatically update and supersede information in this prospectus. We incorporate by reference into this prospectus the documents listed below and any future filings made by us with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act until we close this offering, including all filings made after the date of the initial registration statement. We hereby incorporate by reference the following documents:

Any statement contained in a document, all or a portion of which is incorporated or deemed to be incorporated by reference herein, will be deemed to be modified or superseded to the extent that a statement contained herein or in any other subsequently filed document which also is or is deemed to be incorporated by reference herein modifies or supersedes such statement. Any statement so modified will not be deemed to constitute a part hereof, except as so modified, and any statement so superseded will not be deemed to constitute a part hereof.

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

Celcuity Inc.

16305 36th Avenue N., Suite 100

Minneapolis, MN 55446
Attention: Investor Relations
Phone: (763) 392-0767

Copies of these filings are also available, without charge, through the “Investors” section of our website (www.celcuity.com) as soon as reasonably practicable after they are filed electronically with the SEC. Please note, however, that information on our website is not, and should not be deemed to be, a part of this prospectus.

LEGAL MATTERS

Unless otherwise specified in a prospectus supplement accompanying this prospectus, the validity of the issuance of the securities offered hereby will be passed upon for us by Faegre Drinker Biddle & Reath LLP. Any underwriters or agents will also be advised about legal matters by their own counsel, which will be named in the prospectus supplement.

EXPERTS

The financial statements as of December 31, 2024 and December 31, 2023 and for the years ended December 31, 2024 and December 31, 2023, incorporated by reference in this prospectus, have been so incorporated in reliance on the report of Boulay PLLP, an independent registered public accounting firm, incorporated by reference herein, given on the authority of said firm as experts in auditing and accounting.

PROSPECTUS

CELCUITY INC.

Common Stock

Preferred Stock

Warrants

Debt Securities

Units

January 9, 2026

PROSPECTUS SUPPLEMENT

(To Prospectus dated January 9, 2026)

Up to $400,000,000

Common Stock

We have previously entered into an Open Market Sale Agreement^SM (the “Sale Agreement”) with Jefferies LLC (“Sales Agent” or “Jefferies”), dated February 4, 2022, relating to the sale of shares of our common stock, par value $0.001 per share. In accordance with the terms of the Sale Agreement, under this prospectus supplement we may offer and sell shares of our common stock having an aggregate offering price of up to $400,000,000 from time to time through Jefferies acting as sales agent. We previously filed a prospectus supplement, dated December 6, 2024, for the offer and sale of up to $125,000,000, under a shelf registration statement on Form S-3 (Registration No. 333-281887), as amended by Prospectus Supplement No. 1 dated July 29, 2025, decreasing the offering amount to up to $50,000,000 of our common stock pursuant to the Sale Agreement (the “Prior Prospectus Supplement”). As of immediately prior to the filing date of this prospectus supplement, we have not issued any shares of common stock under the Sale Agreement and the Prior Prospectus Supplement. As of the date of this prospectus supplement, the offering pursuant to the Prior Prospectus Supplement has been terminated and we will not make any offers or sales of shares of our common stock pursuant to the Prior Prospectus Supplement.

Our common stock is listed on The Nasdaq Capital Market (“Nasdaq”) under the symbol “CELC.” On January 6, 2026, the last reported sale price of our common stock was $105.02 per share.

Sales of our common stock, if any, under this prospectus supplement may be made by any method deemed to be an “at the market offering” as defined in Rule 415(a)(4) promulgated under the Securities Act of 1933, as amended (the “Securities Act”). Jefferies is not required to sell any specific amount of securities, but will act as our sales agent using commercially reasonable efforts, consistent with its normal trading and sales practices, on mutually agreed terms between Jefferies and us. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.

Jefferies will be entitled to compensation at a commission rate of up to 3.0% of the gross proceeds of the shares of common stock sold under the Sale Agreement. In connection with the sale of the common stock on our behalf, Jefferies will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of Jefferies will be deemed to be underwriting commissions or discounts. We have also agreed to provide indemnification and contribution to the Sales Agent with respect to certain liabilities, including civil liabilities under the Securities Act. See “Plan of Distribution” for additional information regarding the compensation to be paid to the Sales Agent.

Investing in our securities involves a high degree of risk. You should read this prospectus supplement and the accompanying prospectus as well as the information incorporated herein and therein by reference carefully before you make your investment decision. See “Risk Factors” beginning on page S-4 of this prospectus supplement and on page 5 of the accompanying prospectus.

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

Jefferies

The date of this prospectus supplement is January 9, 2026.

TABLE OF CONTENTS

You should rely only on the information we have provided or incorporated by reference in this prospectus supplement and the accompanying prospectus. We have not, and Jefferies has not, authorized anyone to provide you with information different from that contained or incorporated by reference in this prospectus supplement or the accompanying prospectus.

This prospectus supplement and any later prospectus supplement is an offer to sell only the securities offered hereby, but only under circumstances and in jurisdictions where it is lawful to do so.

You should assume that the information contained in this prospectus supplement and in any other prospectus supplement is accurate only as of their respective dates and that any information we have incorporated by reference is accurate only as of the date of the document incorporated by reference, regardless of the time of delivery of this prospectus supplement or any other prospectus supplement for any sale of securities.

ABOUT THIS PROSPECTUS SUPPLEMENT

This prospectus supplement is part of an automatic shelf registration statement that we filed with the Securities and Exchange Commission (the “SEC”) as a “well-known seasoned issuer” as defined in Rule 405 under the Securities Act, using a “shelf” registration process. By using a shelf registration statement, we may offer shares of our common stock having an aggregate offering price of up to $400,000,000 from time to time under this prospectus supplement at prices and on terms to be determined by market conditions at the time of offering. This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of this common stock offering and also adds to and updates information contained in the accompanying prospectus and the documents incorporated by reference herein and therein. The second part, the accompanying prospectus, provides more general information. To the extent there is a conflict between the information contained in this prospectus supplement and the information contained in the accompanying prospectus or any document incorporated by reference therein filed prior to the date of this prospectus supplement, you should rely on the information in this prospectus supplement; provided that if any statement in one of these documents is inconsistent with a statement in another document having a later date—for example, a document incorporated by reference in the accompanying prospectus—the statement in the document having the later date modifies or supersedes the earlier statement.

We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference herein were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

Neither we nor the Sales Agent have authorized anyone to provide information different from that contained in this prospectus supplement and the accompanying prospectus, including any free writing prospectus that we have authorized for use in this offering. When you make a decision about whether to invest in our common stock, you should not rely upon any information other than the information in this prospectus supplement or the accompanying prospectus, including any free writing prospectus that we have authorized for use in this offering. Neither the delivery of this prospectus supplement or the accompanying prospectus, including any free writing prospectus that we have authorized for use in this offering, nor the sale of our common stock means that information contained in this prospectus supplement and the accompanying prospectus, including any free writing prospectus that we have authorized for use in this offering, is correct after their respective dates. It is important for you to read and consider all information contained in this prospectus supplement and the accompanying prospectus, including the information incorporated by reference into this prospectus supplement and the accompanying prospectus, and any free writing prospectus that we have authorized for use in connection with this offering in making your investment decision. You should also read and consider the information in the documents to which we have referred you in the sections entitled “Where You Can Find More Information” and “Incorporation of Documents by Reference” in this prospectus supplement.

We are offering to sell, and seeking offers to buy, shares of our common stock only in jurisdictions where offers and sales are permitted.

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

In this prospectus, “Celcuity,” “we,” “our,” “ours,” and “us” refer to Celcuity Inc., except where the context otherwise requires or as otherwise indicated. When we refer to “you,” we mean the potential holder of our common stock.

This prospectus supplement and the accompanying prospectus may contain and incorporate by reference market data and industry statistics and forecasts that are based on independent industry publications and other publicly available information. Although we believe these sources are reliable, we do not guarantee the accuracy or completeness of this information and we have not independently verified this information. In addition, the market and industry data and forecasts that may be included or incorporated by reference in this prospectus supplement and the accompanying prospectus may involve estimates, assumptions and other risks and uncertainties and are subject to change based on various factors, including those discussed under the heading “Risk Factors” contained in this prospectus supplement, the accompanying prospectus and under similar headings in other documents that are incorporated by reference into this prospectus supplement and the accompanying prospectus.

RISK FACTORS

An investment in our common stock involves certain risks. You should carefully consider the risks described below and those discussed in our most recent Annual Report under the section titled “Risk Factors” in Part I, Item 1A, in our subsequent Quarterly Reports under the section titled “Risk Factors” in Part II, Item 1A, and in our other filings with the SEC before making an investment decision. Our business, financial condition or results of operations could be materially adversely affected by any of these risks. The market or trading price of our common stock could decline due to any of these risks, and you may lose all or part of your investment. You should also refer to the other information included and incorporated by reference in this prospectus supplement, the accompanying prospectus and any related free writing prospectus, especially our financial statements and related notes, before making an investment decision. As used in this section, “we,” “our” and “us” refer to Celcuity Inc.

Risks Relating to This Offering

We have broad discretion in the use of the net proceeds from this offering and may not use them effectively.

Our management will have broad discretion in the application of the net proceeds from this offering and could spend the proceeds in ways that do not improve our results of operations or enhance the value of our common stock. You will not have the opportunity to influence our decisions on how to use our net proceeds from this offering. The failure by our management to apply these funds effectively could result in financial losses that could cause the price of our common stock to decline and delay the development of our product candidates. Pending their use, we may invest the net proceeds from this offering in a manner that does not produce income or that loses value.

The issuance or sale of shares of our common stock, or the perception of such sales, could depress the trading price of our common stock.

We may conduct future offerings of our common stock, preferred stock or other securities that are convertible into, or exercisable or exchangeable for, our common stock to finance our operations or fund acquisitions, or for other purposes. In addition, we have shares reserved and available for issuance pursuant to our 2017 Employee Stock Purchase Plan and our Amended and Restated 2017 Stock Incentive Plan. If we issue additional shares of our common stock or rights to acquire shares of our common stock or if any of our existing stockholders sells a substantial amount of our common stock, or if the market perceives that such issuances or sales may occur, then the trading price of our common stock could decline.

If you purchase common stock in this offering, you may experience immediate and substantial dilution.

The offering price per share in this offering may exceed the net tangible book value per share of our common stock outstanding prior to this offering. Assuming that an aggregate of 3,808,798 shares of our common stock are sold during the term of the Sale Agreement with the Sales Agent at a price of $105.02 per share, the last reported sale price of our common stock on Nasdaq on January 6, 2026, for aggregate proceeds of approximately $400.0 million, after deducting commissions and estimated aggregate offering expenses payable by us, you will experience immediate dilution of $95.47 per share, representing the difference between our as adjusted net tangible book value per share as of September 30, 2025 after giving effect to this offering and the assumed offering price. The exercise of outstanding stock options and warrants or the conversion of outstanding convertible notes may result in further dilution of your investment. See the section entitled “Dilution” below for a more detailed illustration of the dilution you would incur if you participate in this offering.

You may experience future dilution as a result of future equity offerings.

We may choose to raise additional capital due to market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans. To the extent that additional capital is raised through the sale of equity or convertible debt or other equity linked securities, the issuance of these securities could result in further dilution to our stockholders or result in downward pressure on the price of our common stock.

The price of our common stock may fluctuate substantially, and you may not be able to resell shares of your common stock at or above the price you paid.

Our stock price may be extremely volatile. The stock market in general and the market for smaller medical technology companies in particular have experienced extreme volatility that has often been unrelated to the operating performance of particular companies. As a result of this volatility, investors may not be able to sell our common stock at or above the price they paid for such stock. The market price for our common stock may be influenced by many factors, including:

Additionally, companies that have experienced volatility in the market price of their stock have been subject to an increased incidence of securities class action litigation. We may be the target of this type of litigation in the future. Securities litigation against us could result in substantial costs and divert our management’s attention from other business concerns, which could seriously harm our business.

If securities or industry analysts do not publish research or reports about our business, or publish negative reports about our business, our stock price and trading volume could decline.

The trading market for our common stock depends in part on the research and reports that securities or industry analysts publish about us or our business. We do not have any control over these analysts. There can be no assurance that analysts will cover us or provide favorable coverage. If one or more of the analysts who cover us downgrade our stock or change their opinion of our stock, our stock price would likely decline. If one or more of these analysts cease coverage of our company or fail to regularly publish reports on us, we could lose visibility in the financial markets, which could cause our stock price or trading volume to decline.

The common stock offered hereby will be sold in “at the market” offerings, and investors who buy shares at different times will likely pay different prices.

Investors who purchase shares in this offering at different times will likely pay different prices, and so may experience different outcomes in their investment results. We will have discretion, subject to market demand, to vary the timing, prices, and numbers of shares sold, and there is no minimum or maximum sales price. Investors may experience a decline in the value of their shares as a result of share sales made at prices lower than the prices they paid.

The actual number of shares we will issue under the Sale Agreement, at any one time or in total, is uncertain.

Subject to certain limitations in the Sale Agreement and compliance with applicable law, we have the discretion to deliver a sales notice to the Sales Agent at any time throughout the term of the Sale Agreement. The number of shares that are sold by the Sales Agent after delivering a sales notice will fluctuate based on the market price of the common stock during the sales period and limits we set with Jefferies. Because the price per share of each share sold will fluctuate based on the market price of our common stock during the sales period, it is not possible at this stage to predict the number of shares that will be ultimately issued.

SPECIAL NOTE ABOUT FORWARD-LOOKING STATEMENTS

The Private Securities Litigation Reform Act of 1995 provides a “safe harbor” for forward-looking statements. This prospectus supplement, the accompanying prospectus and the documents incorporated herein by reference contain forward-looking statements regarding us, our business prospects and our results of operations that are subject to certain risks and uncertainties that could cause our actual business, prospects and results of operations to differ materially from those that may be anticipated by such forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, those described under “Risk Factors” herein and in our other filings with the SEC. You should not place undue reliance on these forward-looking statements, which speak only as of the date such forward-looking statement is made. We expressly disclaim any intent or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. You are urged to carefully review and consider the various disclosures made by us in this prospectus supplement, the accompanying prospectus and the documents incorporated herein by reference and in our other reports filed with the SEC that advise interested parties of the risks and uncertainties that may affect our business.

All statements, other than statements of historical facts, contained in this prospectus supplement, the accompanying prospectus and the documents incorporated herein by reference, including statements regarding our plans, objectives and expectations for our business, operations and financial performance and condition, are forward-looking statements. In some cases, you can identify forward-looking statements by the following words: “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “might,” “ongoing,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “will,” “would,” or the negative of these terms or other comparable terminology, although not all forward-looking statements contain these words. Forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause our results, performance or achievements to be materially different from the information expressed or implied by the forward-looking statements in this prospectus supplement, the accompanying prospectus and the documents incorporated herein by reference. Additionally, our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments that we may make. Forward-looking statements may include, among other things, statements relating to:

These statements involve known and unknown risks, uncertainties and other factors that may cause our results or our industry’s actual results, levels of activity, performance or achievements to be materially different from the information expressed or implied by these forward-looking statements. Certain risks, uncertainties and other factors include, but are not limited to, our limited operating history; our potential inability to develop, validate, obtain regulatory approval for and commercialize gedatolisib on a timely basis or at all; the uncertainties and costs associated with clinical studies and with developing and commercializing biopharmaceuticals; the complexity and difficulty of demonstrating the safety and sufficient magnitude of benefit to support regulatory approval of gedatolisib and other products we may develop; challenges we may face in developing and maintaining relationships with pharmaceutical company partners, including our current and any future suppliers of our product candidate; the uncertainty and costs associated with clinical trials; the uncertainty regarding market acceptance by physicians, patients, third-party payors and others in the medical community, and with the size of market opportunities available to us; difficulties we may face in managing growth, such as hiring and retaining a qualified sales force and attracting and retaining key personnel; changes in government regulations; tightening credit markets and limitations on access to capital; stock market volatility or other factors that may affect our ability to access capital on favorable terms or at all; and obtaining and maintaining intellectual property protection for gedatolisib and time and expense associated with defending third-party claims of intellectual property infringement, investigations or litigation threatened or initiated against us. See “Risk Factors” beginning on page S-4 of this prospectus supplement for additional risks, uncertainties and other factors applicable to us.

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

USE OF PROCEEDS

We may issue and sell shares of our common stock having aggregate sales proceeds of up to $400.0 million from time to time. Because there is no minimum offering amount required as a condition to close this offering, the actual total public offering amount, commissions and proceeds to us, if any, are not determinable at this time. There can be no assurance that we will sell any shares under this prospectus supplement and the accompanying prospectus or fully utilize the Sale Agreement with Jefferies as a source of financing.

We currently intend to use the net proceeds from this offering for working capital and general corporate purposes. General corporate purposes may include clinical trial expenditures, commercial launch expenditures (including sales, marketing and reimbursement functions), research and development expenditures, capital expenditures, expansion of business development activities and other general corporate purposes. We may also use a portion of our net proceeds for the potential acquisition of businesses, technologies and products, although we have no current binding understandings, commitments or agreements to do so.

The amounts and timing of our expenditures will depend on numerous factors, including the status, results and timing of our current and expected clinical trials involving gedatolisib and other corporate developments. Accordingly, our management will have broad discretion over the use of the net proceeds from the sale of any securities offered by us.

DIVIDEND POLICY

We have never declared or paid any cash dividends on our common stock and currently do not anticipate paying any cash dividends for the foreseeable future. We have historically retained earnings, and expect to continue to retain future earnings, to finance the operation and expansion of our business. Any future determination relating to dividend policy will be made at the discretion of our board of directors and will depend on our future earnings, capital requirements, financial condition, future prospects, applicable law and other factors that our board of directors deems relevant. We are currently prohibited from paying cash dividends to stockholders pursuant to a restrictive covenant in our Amended A&R Loan Agreement, and any future debt financing agreements may include similar provisions.

DILUTION

If you purchase our common stock in this offering, your interest will be diluted to the extent of the difference between the public offering price per share and the net tangible book value per share of our common stock after this offering. We calculate net tangible book value per share by dividing our net tangible assets (tangible assets less total liabilities) by the number of shares of our common stock issued and outstanding as of September 30, 2025.

Our net tangible book value at September 30, 2025 was approximately $117.0 million, or $2.37 per share. After giving effect to the sale of our common stock during the term of the Sale Agreement with the Sales Agent in the aggregate amount of $400.0 million at an assumed offering price of $105.02 per share, the last reported sale price of our common stock on Nasdaq on January 6, 2026, and after deducting commissions and estimated aggregate offering expenses payable by us, our as adjusted net tangible book value as of September 30, 2025 would have been approximately $508.2 million, or $9.55 per share of common stock. This represents an immediate increase in the net tangible book value of $7.18 per share to our existing stockholders and an immediate dilution in net tangible book value of $95.47 per share to new investors. The following table illustrates this per share dilution:

The foregoing table and calculations are based on 43,274,548 shares of common stock outstanding as of September 30, 2025, plus 6,147,787 shares of common stock issuable upon the exercise of outstanding pre-funded warrants for nominal consideration, and does not include, as of that date:

To the extent that options or warrants as of September 30, 2025 have been or are exercised, or other shares are issued, investors purchasing shares in this offering could experience further dilution. In addition, we may choose to raise additional capital due to market conditions or strategic considerations, even if we believe we have sufficient funds for our current or future operating plans. To the extent that additional capital is raised through the sale of equity or convertible debt securities, the issuance of these securities could result in further dilution to our stockholders.

PLAN OF DISTRIBUTION

We have previously entered into the Sale Agreement with Jefferies, under which we may offer and sell our shares of common stock from time to time through Jefferies acting as agent. Pursuant to this prospectus supplement and the accompanying prospectus, we may offer and sell shares of our common stock having an aggregate offering price of up to $400,000,000. As of immediately prior to the filing date of this prospectus supplement, we have not issued any shares of common stock under the Sale Agreement and the Prior Prospectus Supplement. As of the date of this prospectus supplement, the offering pursuant to the Prior Prospectus Supplement has been terminated and we will not make any offers or sales of shares of our common stock pursuant to the prior Prospectus Supplement.

Offers and sales of our shares of common stock, if any, under this prospectus supplement and the accompanying prospectus may be made by any method permitted by law deemed to be an “at the market offering” as defined in Rule 415(a)(4) under the Securities Act, including sales made directly on Nasdaq or sales made into any other existing trading market of our common stock.

Each time we wish to issue and sell shares of common stock under the Sale Agreement, we will notify Jefferies of the number of shares to be issued, the dates on which such sales are anticipated to be made, any limitation on the number of shares to be sold in any one day and any minimum price below which sales may not be made. Once we have so instructed Jefferies, unless Jefferies declines to accept the terms of such notice, Jefferies has agreed to use its commercially reasonable efforts consistent with its normal trading and sales practices to sell such shares up to the amount specified on such terms. The obligations of Jefferies under the Sale Agreement to sell our shares of common stock are subject to a number of conditions that we must meet.

The settlement of sales of shares between us and Jefferies is generally anticipated to occur on the first trading day following the date on which the sale was made. Sales of our shares of common stock as contemplated in this prospectus supplement and the accompanying prospectus will be settled through the facilities of The Depository Trust Company or by such other means as we and Jefferies may agree upon. There is no arrangement for funds to be received in an escrow, trust or similar arrangement.

We will pay Jefferies a commission of up to 3.0% of the aggregate gross proceeds we receive from each sale of our shares of common stock. Because there is no minimum offering amount required as a condition to close this offering, the actual total public offering amount, commissions and proceeds to us, if any, are not determinable at this time. In addition, we previously reimbursed Jefferies for the fees and disbursements of its counsel upon execution of the Sale Agreement in the amount of $75,000. We also have agreed to reimburse Jefferies for certain ongoing disbursements of its legal counsel, unless we and Jefferies otherwise agree. We estimate that the total expenses for the offering, excluding any commissions or expense reimbursement payable to Jefferies under the terms of the Sale Agreement, will be approximately $347,500. The remaining sale proceeds, after deducting any other transaction fees, will equal our net proceeds from the sale of such shares.

Jefferies will provide written confirmation to us before the open on Nasdaq on the day following each day on which shares of common stock are sold under the Sale Agreement. Each confirmation will include the number of shares sold on that day, the aggregate gross proceeds of such sales and the proceeds to us.

In connection with the sale of the shares of common stock on our behalf, Jefferies will be deemed to be an “underwriter” within the meaning of the Securities Act, and the compensation of Jefferies will be deemed to be underwriting commissions or discounts. We have agreed to indemnify Jefferies against certain civil liabilities, including liabilities under the Securities Act. We have also agreed to contribute to payments Jefferies may be required to make in respect of such liabilities.

The offering of our shares of common stock pursuant to the Sale Agreement will terminate as permitted therein.

This summary of the material provisions of the Sale Agreement does not purport to be a complete statement of its terms and conditions and is qualified in its entirety by reference to the full text of the Sale Agreement, a copy of which was included as Exhibit 1.1 to our Current Report on Form 8-K filed with the SEC on February 4, 2022, and is incorporated herein by reference.

Jefferies and its affiliates have in the past and may in the future provide various investment banking, commercial banking, financial advisory and other financial services for us and our affiliates, for which services they may in the future receive customary fees. In the course of its business, Jefferies may actively trade our securities for its own account or for the accounts of customers, and, accordingly, Jefferies may at any time hold long or short positions in such securities.

The prospectus supplement and the accompanying prospectus in electronic format may be made available on a website maintained by Jefferies, and Jefferies may distribute the prospectus supplement and the accompanying prospectus electronically.

LEGAL MATTERS

The validity of the issuance of the common stock offered hereby will be passed upon for us by Faegre Drinker Biddle & Reath LLP. Jefferies LLC is being represented in connection with this offering by Cooley LLP, New York, New York.

EXPERTS

The financial statements included in our Annual Report on Form 10-K for the years ended December 31, 2024 and December 31, 2023, incorporated by reference in this prospectus supplement and the accompanying prospectus, have been so incorporated in reliance on the report of Boulay PLLP, an independent registered public accounting firm, and given on the authority of said firm as experts in auditing and accounting.

WHERE YOU CAN FIND MORE INFORMATION

This prospectus supplement constitutes a part of a registration statement on Form S-3 (the “Registration Statement,” which term shall encompass all amendments, exhibits, annexes and schedules thereto and all documents incorporated by reference therein) pursuant to the Securities Act, and the rules and regulations promulgated thereunder. As permitted by the SEC’s rules, the base prospectus and this prospectus supplement, which form a part of the Registration Statement, do not contain all the information that is included in the Registration Statement. For further information with respect to us and the securities offered hereby, reference is made to the Registration Statement.

We are required to file annual and quarterly reports, special reports, proxy statements, and other information with the SEC. The SEC maintains a website that contains reports, proxy and information statements and other information regarding issuers, including us, that file electronically with the SEC. You may obtain documents that we file with the SEC at http://www.sec.gov. We also make these documents publicly available, free of charge, on our website at www.celcuity.com as soon as reasonably practicable after filing such documents with the SEC. Please note, however, that information on, or accessible through, our website is not, and should not be deemed to be, a part of this prospectus supplement and should not be relied upon in connection with making any investment decision with respect to the offered securities.

INCORPORATION OF DOCUMENTS BY REFERENCE

The SEC allows us to “incorporate by reference” into this prospectus supplement the information we file with it, which means that we can disclose important information to you by referring to those documents. The information incorporated by reference is considered to be part of this prospectus supplement, and information in documents that we file later with the SEC will automatically update and supersede information in this prospectus supplement. We incorporate by reference into this prospectus supplement the documents listed below and any future filings made by us with the SEC under Section 13(a), 13(c), 14 or 15(d) of the Exchange Act until the completion or termination of this offering. We hereby incorporate by reference the following documents:

Any statement contained in a document, all or a portion of which is incorporated or deemed to be incorporated by reference herein, will be deemed to be modified or superseded to the extent that a statement contained herein or in any other subsequently filed document which also is or is deemed to be incorporated by reference herein modifies or supersedes such statement. Any statement so modified will not be deemed to constitute a part hereof, except as so modified, and any statement so superseded will not be deemed to constitute a part hereof.

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

Celcuity Inc.

16305 36th Avenue N., Suite 100

Minneapolis, MN 55446

Attention: Investor Relations

Phone: (763) 392-0767

Copies of these filings are also available, without charge, through the “Investors” section of our website (www.celcuity.com) as soon as reasonably practicable after they are filed electronically with the SEC. Please note, however, that information on our website is not, and should not be deemed to be, a part of this prospectus supplement.

Up to $400,000,000

Common Stock

PROSPECTUS SUPPLEMENT

Jefferies

January 9, 2026

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution.

The following table sets forth the various expenses in connection with the sale and distribution of the securities being registered. All amounts shown are estimates, except the SEC registration fee. The registrant has agreed to pay these costs and expenses.

Item 15. Indemnification of Directors and Officers.

Section 102(b)(7) of the Delaware General Corporation Law (the “DGCL”), provides that a Delaware corporation, in its certificate of incorporation, may limit the personal liability of a director or officer to the corporation or its stockholders for monetary damages for breach of fiduciary duty as a director or officer, except the liability of:

Section 145(a) of the DGCL provides, in general, that a Delaware corporation may indemnify any person who was or is a party, or is threatened to be made a party, to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of the corporation) by reason of the fact that the person is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation or other enterprise. The indemnity may include expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by the person in connection with such action, so long as the person acted in good faith and in a manner he or she reasonably believed was in or not opposed to the corporation’s best interests, and, with respect to any criminal action or proceeding, had no reasonable cause to believe his or her conduct was unlawful.

Section 145(b) of the DGCL provides, in general, that a Delaware corporation may indemnify any person who was or is a party, or is threatened to be made a party, to any threatened, pending or completed action or suit by or in the right of the corporation to obtain a judgment in its favor because the person is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation or other enterprise. The indemnity may include expenses (including attorneys’ fees) actually and reasonably incurred by the person in connection with the defense or settlement of such action, so long as the person acted in good faith and in a manner the person reasonably believed was in or not opposed to the corporation’s best interests, except that no indemnification shall be permitted without judicial approval if a court has determined that the person is to be liable to the corporation with respect to such claim. Section 145(c) of the DGCL provides that, if a present or former director or officer has been successful in defense of any action referred to in Sections 145(a) and (b) of the DGCL, the corporation must indemnify such officer or director against the expenses (including attorneys’ fees) he or she actually and reasonably incurred in connection with such action.

Section 145(g) of the DGCL provides, in general, that a corporation may purchase and maintain insurance on behalf of any person who is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation or other enterprise against any liability asserted against and incurred by such person, in any such capacity, or arising out of his or her status as such, whether or not the corporation could indemnify the person against such liability under Section 145 of the DGCL.

Our certificate of incorporation, as amended, and our bylaws provide for the limitation of liability and indemnification of our directors and officers to the fullest extent permitted under the DGCL.

We have also entered into separate indemnification agreements with our directors and officers in addition to the indemnification provided for in our certificate of incorporation, as amended, and our bylaws. These indemnification agreements provide, among other things, that we will indemnify our directors and officers for certain expenses, including damages, judgments, fines, penalties, settlements and costs and attorneys’ fees and disbursements, incurred by a director or officer in any claim, action or proceeding arising in his or her capacity as a director or officer of us or in connection with service at our request for another corporation or entity. The indemnification agreements also provide for procedures that will apply in the event that a director or officer makes a claim for indemnification.

We also maintain a directors’ and officers’ insurance policy pursuant to which our directors and officers are insured against liability for actions taken in their capacities as directors and officers.

Item 16. Exhibits.

The following is a list of exhibits filed as part of this registration statement:

Item 17. Undertakings.

(a) The undersigned registrant hereby undertakes:

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

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

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

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

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

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

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

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

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

(B) Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5), or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii), or (x) for the purpose of providing the information required by section 10(a) of the Securities Act of 1933 shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

(6) That, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities:

The undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i) Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii) Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;

(iii) The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

(iv) Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

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

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

(j) The undersigned registrant hereby undertakes to file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act in accordance with the rules and regulations prescribed by the Commission under Section 305(b)(2) of the Act.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement on Form S-3 to be signed on its behalf by the undersigned, thereunto duly authorized, in Minneapolis, Minnesota, on January 9, 2026.

POWER OF ATTORNEY

Each person whose signature appears below constitutes and appoints Brian F. Sullivan, Vicky Hahne and Brent Eilefson, and each of them singly, his or her true and lawful attorney-in-fact and agent with full power of substitution and resubstitution, for him or her and in his or her name, place, and stead, in any and all capacities, to sign any and all amendments and supplements (including post-effective amendments) to this Registration Statement on Form S-3 of Celcuity Inc., and any related Rule 462(b) registration statement or amendment thereto and other instruments necessary or appropriate in connection therewith, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents (and each of them acting singly) full power and authority to do all such things in his or her name and on his or her behalf in their capacity as an officer and/or director to enable Celcuity Inc. to comply with the provisions of the Securities Act of 1933, as amended, and all requirements of the Securities and Exchange Commission, hereby ratifying and confirming all that said attorneys-in-fact, or any of them or their agents, substitutes or resubstitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated: