This prospectus relates to the offering and resale from time to time by the selling stockholders identified in this prospectus (the “Selling Stockholders”) of up to 16,754,154 shares of our common stock, $0.005 par value per share (“common stock”), composed of (i) 2,184,950 shares of common stock issued in a private placement consummated in December 2022 (the “December Private Placement”), (ii) up to 4,369,900 shares of common stock issuable upon exercise of warrants issued to certain Selling Stockholders in such private placement, (iii) up to 3,047,196 shares of common stock issuable upon the conversion of the Company’s 6% Senior Convertible Notes (the “Note Conversion Shares”) that were issued to certain Selling Stockholders in a private placement consummated in July 2023, (iv) up to 1,057,716 shares of common stock that may become issuable upon conversion of capitalized pay-in-kind interest that may accrue through the maturity date of the Notes (the “PIK Interest Conversion Shares” and together with the Note Conversion Shares, the “Conversion Shares”) and (v) up to 6,094,392 shares of common stock issuable upon the exercise of warrants issued to certain Selling Stockholders in such private placement. The foregoing securities issued in the December 2022 Private Placement were acquired by certain Selling Stockholders on December 2, 2022 in a private placement pursuant to a purchase agreement among us and such Selling Stockholders, dated November 23, 2022. The Notes and the warrants issued by us in July 2023 were acquired by certain Selling Stockholders on July 14, 2023 in a private placement pursuant to a purchase agreement among us and such Selling Stockholders, dated July 13, 2023.

We are registering the common stock issued or issuable upon exercise of the warrants issued in December Private Placement pursuant to certain of the Selling Stockholders’ registration rights contained in that certain Registration Rights Agreement, dated December 2, 2022, by and among us and such Selling Stockholders. We are registering the Conversion Shares and the shares of common stock issuable upon exercise of the warrants issued by us in July 2023 pursuant to certain of the Selling Stockholders’ registration rights contained in that certain Registration Rights Agreement, dated July 14, 2023, by and among us and such Selling Stockholders.

The Selling Stockholders may offer, sell or distribute all or a portion of the shares of common stock registered hereby publicly or through private transactions at prevailing market prices or at negotiated pries. We provide more information about how the Selling Stockholders may sell their respective shares of our common stock in the section entitled “Plan of Distribution.”

We will pay certain fees and expenses in connection with the registration of the common stock offered hereby, and we will not receive any proceeds from the Selling Stockholders’ sale of the shares of common stock offered hereby.

Our common stock is listed on the Nasdaq Capital Market under the symbol “ERNA.” On August 11, 2023, the closing price of our common stock was $2.68.

INVESTING IN OUR SECURITIES INVOLVES RISKS THAT ARE DESCRIBED IN THE “RISK FACTORS” SECTION BEGINNING ON PAGE 4 OF THIS PROSPECTUS.

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

You should rely only on the information contained in this prospectus. No one has been authorized to provide you with information that is different from that contained in this prospectus. This prospectus is dated as of the date set forth on the cover hereof. You should not assume that the information contained in this prospectus is accurate as of any date other than that date.

This prospectus is part of a registration statement that we filed with the U.S. Securities and Exchange Commission (“SEC”) under the Securities Act of 1933, as amended (the “Securities Act”), using a “shelf” registration process. Under this prospectus, the Selling Stockholders may, from time to time, sell shares of our common stock described in this prospectus in one or more offerings. This prospectus provides you with a general description of the securities offered by the Selling Stockholders. Any prospectus supplement may also add, update or change information contained in this prospectus. Any statement that we make in this prospectus will be modified or superseded by any inconsistent statement made by us in a prospectus supplement.

The registration statement we filed with the SEC includes exhibits that provide more detail of the matters discussed in this prospectus. This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part. You should read this prospectus and the related exhibits filed with the SEC and any prospectus supplement, together with additional information described under the headings “Where You Can Find More Information” and “Incorporation by Reference” before making your investment decision.

You should rely only on the information incorporated by reference or provided in this prospectus, any prospectus supplement and the registration statement. Neither we nor any Selling Stockholder has authorized anyone else to provide you with different or additional information other than that contained in or incorporated by reference in this prospectus. If anyone provides you with different or inconsistent information, you should not rely on it. Offers to sell, and solicitations of offers to buy, our common stock are being made only in jurisdictions where offers and sales are permitted. You should assume that the information in this prospectus and any prospectus supplement, or incorporated by reference, is accurate only as of the respective dates of those documents. Our business, financial condition, results of operations and prospects may have changed since those dates.

An investment in our common stock involves a high degree of risk. You should consider carefully the risks and uncertainties described under the heading “Risk Factors” in Item 1A of Part I of our Annual Report on Form 10-K for the year ended December 31, 2022, which is incorporated by reference in this prospectus, including our audited consolidated financial statements and the related notes, before you decide whether to purchase our common stock. If any of such risks actually occur, our business, financial condition, results of operations, cash flow and prospects could be materially and adversely affected. As a result, the trading price of our common stock could decline and you could lose all or part of your investment in our common stock.

This prospectus contains forward-looking statements. Certain statements in this prospectus may constitute “forward-looking statements” for purposes of the federal securities laws. Our forward-looking statements include, but are not limited to, statements regarding expectations, hopes, beliefs, intentions or strategies regarding the future. In addition, any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. The words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intends,” “may,” “might,” “plan,” “possible,” “potential,” “predict,” “project,” “should,” “will,” “would” and similar expressions may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking. Forward-looking statements in this prospectus may include, for example, statements about:

The forward-looking statements contained in this prospectus are based on current expectations and beliefs concerning future developments and their potential effects on the Company. There can be no assurance that future developments affecting us will be those that we have anticipated. These forward-looking statements involve a number of risks, uncertainties, some of which are beyond our control, or other assumptions that may cause actual results or performance to be materially different from those expressed or implied by these forward-looking statements. These risks and uncertainties include, but are not limited to, those factors described in the section entitled “Risk Factors” and in our periodic filings with the SEC. Our SEC filings are available publicly on the SEC website at www.sec.gov. Should one or more of these risks or uncertainties materialize, or should any of our assumptions prove incorrect, actual results may vary in material respects from those projected in these forward-looking statements. Accordingly, forward-looking statements in this prospectus should not be relied upon as representing our views as of any subsequent date, and we undertake no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as may be required under applicable securities laws.

We will not receive any of the proceeds from the sale of any common stock offered by this prospectus, but we will bear all fees and expenses incident to our obligation to register the shares of common stock being offered for resale hereunder by the Selling Stockholders.

We may receive proceeds from the exercise of the Warrants and issuance of the underlying shares of common stock. If all of the December PIPE Warrants and July PIPE Warrants were exercised for cash in full, the proceeds would be approximately $14.3 million and $15.9 million, respectively. We intend to use the net proceeds of such warrant exercises, if any, for research and development, general and administrative expenses, and for working capital purposes. We can make no assurances that any of the Warrants will be exercised, or if exercised, that they will be exercised for cash.

The following summary of the material terms of our capital stock is not intended to be a complete summary of the rights and preferences of such securities. We urge you to read our restated certificate of incorporation, including the amendments thereto, which we refer to as our certificate of incorporation, and our amended and restated bylaws, which we refer to our bylaws, in its entirety for a complete description of the rights and preferences of our capital stock.

Our authorized capital stock consists of 100,000,000 shares of common stock, par value $0.005 per share, and 1,000,000 shares of preferred stock, par value $0.005 per share (the “preferred stock”). A total of 156,112 shares of preferred stock have been designated as Series A Convertible Preferred Stock. As of August 9, 2023, 5,410,331 shares of common stock were outstanding and 156,112 shares of Series A Convertible Preferred Stock were outstanding.

Each holder of common stock is entitled to one vote for each share on all matters submitted to a vote of the stockholders, including the election of directors. Votes may be cast in person or by proxy. Stockholders do not have cumulative voting rights with respect to election of directors.

The holders of Series A Convertible Preferred Stock are entitled to receive cumulative dividends of $0.10 per share per annum, payable semiannually in equal installments of $0.05 per share on June 1 and December 1 of each year. After the requirements with respect to the preferential dividends of the preferred stock have been met, holders of common stock are entitled to receive proportionately any dividends as may be declared and paid on common stock from funds lawfully available therefor as and when determined by the board of directors, subject to any preferential dividend rights of outstanding preferred stock.

In the event of our liquidation or dissolution, the holders of common stock are entitled to receive proportionately all assets available for distribution to stockholders after the payment of all debts and other liabilities and subject to the prior rights of any outstanding preferred stock.

Holders of common stock have no preemptive, subscription, redemption or conversion rights and there are no sinking fund provisions with respect to our common stock. The rights, preferences and privileges of holders of common stock are subject to and may be adversely affected by the rights of the holders of shares of any series of preferred stock. All of the shares of the common stock currently issued and outstanding are fully-paid and nonassessable.

Our certificate of incorporation and bylaws and the Delaware General Corporation Law (“DGCL”) contain provisions that could have the effect of delaying, deferring or discouraging another party from acquiring control of us. These provisions, which are summarized below, are expected to discourage coercive takeover practices and inadequate takeover bids and are designed in part to encourage persons seeking to acquire control of us to first negotiate with the board of directors.

Our certificate of incorporation provides that the number of directors is established by the board of directors, which may delay the ability of stockholders to change the composition of a majority of the board. The board has the exclusive right to elect a director to fill any vacancy or newly created directorship.

A director may be removed only by the affirmative vote of the holders of at least 80% of the voting power of all shares entitled to vote generally in the election of directors, voting together as a single class.

Our certificate of incorporation provides that any action required or permitted to be taken by our stockholders must be effected at a duly called annual or special meeting of such holders and may not be effected by any consent in writing by such holders. Our certificate of incorporation and bylaws also provide that, except as otherwise required by law, special meetings of our stockholders can only be called by the board of directors. These provisions may delay the ability of our stockholders to force consideration of a proposal or to take action, including the removal of directors.

Our bylaws establish an advance notice procedure for stockholder proposals to be brought before an annual meeting of stockholders, including proposed nominations of persons for election to the board of directors. Stockholders at an annual meeting may consider proposals or nominations specified in the notice of meeting or brought before the meeting by or at the direction of the board or by a stockholder of record on the record date for the meeting who is entitled to vote at the meeting and who has delivered timely written notice in proper form to our secretary of the stockholder’s intention to bring such business before the meeting. These provisions could have the effect of delaying until the next stockholder meeting stockholder actions that are favored by the holders of a majority of our outstanding voting securities.

We are a Delaware corporation subject to Section 203 of the DGCL. Under Section 203, certain “business combinations” between a Delaware corporation whose stock is listed on a national securities exchange or held of record by more than 2,000 stockholders and an “interested stockholder” are prohibited for a three-year period following the date that such stockholder became an interested stockholder, unless:

The three-year prohibition also does not apply to some business combinations proposed by an interested stockholder following the announcement or notification of an extraordinary transaction involving the corporation and a person who had not been an interested stockholder during the previous three years or who became an interested stockholder with the approval of a majority of the corporation’s directors. The term “business combination” is defined generally to include mergers or consolidations between a Delaware corporation and an interested stockholder, transactions with an interested stockholder involving the assets or stock of the corporation or its majority-owned subsidiaries and transactions which increase an interested stockholder’s percentage ownership of stock, or other transaction resulting in a financial benefit to the interested stockholder. The term “interested stockholder” is defined generally as those stockholders who become beneficial owners of 15% or more of a Delaware corporation’s voting stock, together with the affiliates or associates of that stockholder.

Any provision of our certificate of incorporation may be amended, altered, changed or repealed in any manner prescribed by law; provided, that (a) the affirmative vote of the holders of at least 80% of the voting power of all

shares entitled to vote generally in the election of directors, voting together as a single class, is required to alter, amend, or repeal, or adopt any provision inconsistent with Article X of the certificate of incorporation, which contains the prohibition on stockholder action by written consent and the requirement that special meetings be called only by the board of directors, and (b) Article XI of the certificate of incorporation, provides that, subject to certain exceptions, no purchase by or from any Controlling Person (as defined below) of shares of our stock owned by such Controlling Person shall be made at a price exceeding the average price paid by such Controlling Person for all shares of our stock acquired by such Controlling Person during the two-year period preceding the date of such proposed purchase unless such purchase is approved by the affirmative vote of not less than a majority of the voting power of the shares of our stock entitled to vote held by Disinterested Stockholders (as defined below), may not be amended without the affirmative vote of not less than a majority of the our stock entitled to vote thereon, provided that if, at the time of such vote, there shall be one or more Controlling Persons, such affirmative vote shall include the affirmative vote in favor of such amendment of not less than a majority of the voting power of the shares of our stock entitled to vote thereon held by Disinterested Stockholders. “Controlling Person” means any individual, corporation, partnership, trust, association or other organization or entity (including any group formed for the purpose of acquiring, voting or holding our securities) which either directly, or indirectly through one or more intermediaries, owns, beneficially or of record, or controls by agreement, voting trust or otherwise, at least 10% of the voting power of stock, and such term also includes any corporation, partnership, trust, association or other organization or entity in which one or more Controlling Persons have the power, through the ownership of voting securities, by contract, or otherwise, to influence significantly any of the management, activities or policies of such corporation, partnership, trust, association, other organization or entity. “Disinterested Stockholders” means those holders of stock entitled to vote on any matter, none of which is a Controlling Person.

The board may, by majority vote, amend or repeal our bylaws and may adopt new bylaws.

Our stockholders may not adopt, amend, or repeal our bylaws or adopt new bylaws except by the vote or written consent of at least 66-2/3% of the voting power of our company.

Our bylaws provide that, unless we consent in writing to the selection of an alternative forum, the a state court located in the State of Delaware (or if no state court has jurisdiction, the federal district court for the District of Delaware) shall be the sole and exclusive forum for (a) any derivative action or proceeding brought on our behalf, (b) any action asserting a claim of breach of a fiduciary duty owed by any of our directors or officers to our company or stockholders, (c) any action asserting a claim against us arising pursuant to any provision of the DGCL or our certificate of incorporation or amended and restated bylaws, or (d) any action asserting a claim against us governed by the internal affairs doctrine. Although our bylaws contain the choice of forum provision described above, it is possible that a court could rule that such a provision is inapplicable for a particular claim or action or that such provision is unenforceable.

Our authorized but unissued shares of common stock and preferred stock are available for future issuance without stockholder approval, subject to any limitations imposed by the listing requirements of The Nasdaq Capital Market. These additional shares may be used for a variety of corporate finance transactions, acquisitions and employee benefit plans. The existence of authorized but unissued and unreserved common stock and preferred stock could make it more difficult or discourage an attempt to obtain control of us by means of a proxy contest, tender offer, merger or otherwise.

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

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

The shares of common stock being offered by the Selling Stockholders are those issued to the Selling Stockholders in the December Private Placement, those issuable to the Selling Stockholders upon exercise of the Warrants and the Conversion Shares, which are those shares of common stock issuable upon conversion of the Notes, inclusive of shares of common stock underlying potential capitalized PIK Interest through the maturity date of the Notes. For additional information regarding the issuance of the foregoing shares of common stock, the Warrants and the Notes, see “Prospectus Summary—December Private Placement of Shares of Common Stock and Warrants” and “Prospectus Summary—July Private Placement of Notes and Warrants” located elsewhere in this prospectus. We are registering the shares of common stock in order to permit the Selling Stockholders to offer the shares for resale from time to time. Except for the ownership of the shares of common stock offered hereby, the Warrants and the Notes, as applicable, and as otherwise disclosed in the footnotes to the table immediately below, none of the Selling Stockholders has had any material relationship with us within the past three years.

The table below lists the Selling Stockholders and other information regarding the beneficial ownership of the shares of common stock by each of the Selling Stockholders. The second column lists the number of shares of common stock beneficially owned by each Selling Stockholder. The beneficial ownership of our common stock is based on 5,410,331 shares of our common stock outstanding as of August 9, 2023.

Beneficial ownership is determined according to the rules of the SEC, which generally provide that a person has beneficial ownership of a security if he, she or it possesses sole or shared voting or investment power over that security, including derivative securities, such as options and warrants, that are currently exercisable or exercisable within 60 days. In computing the number of shares beneficially owned by a particular person or entity and the percentage ownership of that person or entity in the table below, all shares subject to options, Notes and Warrants held by such person or entity were deemed outstanding if such securities are currently exercisable or become exercisable within 60 days following of August 9, 2023. These shares were not deemed outstanding, however, for the purpose of computing the percentage ownership of any other person or entity.

The third column lists the shares of common stock being offered by this prospectus by the Selling Stockholders.

In accordance with the terms of the Registration Rights Agreements, this prospectus covers the resale of the sum of (i) the number of shares of common stock issued to those Selling Stockholders who acquired such shares in the December Private Placement, (ii) the maximum number of shares of common stock issuable upon exercise of the Warrants, determined as if the outstanding Warrants were exercised in full as of the trading day immediately preceding the date the registration statement, of which this prospectus forms a part, was initially filed with the SEC, without regard to any limitations on the exercise of the Warrants, as described below, (iii) the maximum number of shares of common stock issuable upon conversion of the Notes, determined as if the outstanding Notes were converted in full as of the trading day immediately preceding the date the registration statement, of which this prospectus forms a part, was initially filed with the SEC, without regard to any limitations on the conversion of the Notes, as described above, and (iv) the maximum number of PIK Interest Conversion Shares issuable, assuming that the Company pays all interest on the Notes as PIK Interest through the maturity date of the Notes. The fourth column (presenting the number of shares of common stock owned after this offering) assumes the sale of all of the shares offered by the Selling Stockholders pursuant to this prospectus.

Under the terms of the December PIPE Warrants, certain Selling Stockholders may not exercise the December PIPE Warrants to the extent such exercise would result in such Selling Stockholder, together with its affiliates and attribution parties, to beneficially own a number of shares of common stock which would exceed 4.99% or 9.99%, as applicable, of our then outstanding common stock following such exercise, excluding for purposes of such determination shares of common stock issuable upon exercise of such warrants which have not been exercised. The number of shares in the third column (presenting the maximum number of shares of common stock to be sold pursuant to this prospectus) does not reflect this limitation, but the number of shares in all other columns reflect this limitation. The Selling Stockholders may sell all, some or none of their respective shares in this offering. See “Plan of Distribution.”

Under the terms of the Notes, certain Selling Stockholders may not convert the Notes to the extent such conversion would result in such Selling Stockholder, together with its affiliates and attribution parties, to beneficially own a number of shares of common stock which would exceed 4.99%, 9.99% or 19.99%, as applicable, of our then outstanding common stock following such conversion, excluding for purposes of such determination shares of common stock issuable upon conversion of such Notes which have not been converted. The number of shares in the

third column (presenting the maximum number of shares of common stock to be sold pursuant to this prospectus) does not reflect this limitation, but the number of shares in all other columns reflect this limitation. The Selling Stockholders may sell all, some or none of their respective shares in this offering. See “Plan of Distribution.”

Under the terms of the July PIPE Warrants, certain Selling Stockholders may not exercise the July PIPE Warrants to the extent such exercise would result in such Selling Stockholder, together with its affiliates and attribution parties, to beneficially own a number of shares of common stock which would exceed 4.99%, 9.99% or 19.99%, as applicable, of our then outstanding common stock following such exercise, excluding for purposes of such determination shares of common stock issuable upon exercise of such warrants which have not been exercised. The number of shares in the third column (presenting the maximum number of shares of common stock to be sold pursuant to this prospectus) does not reflect this limitation, but the number of shares in all other columns reflect this limitation. The Selling Stockholders may sell all, some or none of their respective shares in this offering. See “Plan of Distribution.”

Unless otherwise noted in the footnotes to the table immediately below, a Selling Stockholder may not exercise the Warrants or convert the Notes to the extent such exercise or conversion, as applicable, would result in such Selling Stockholder, together with its affiliates and attribution parties, to beneficially own a number of shares of common stock which would exceed 4.99% of our then outstanding common stock following such exercise or conversion. Given the foregoing limitations on exercise or conversion, the number of shares of common stock beneficially owned by a Selling Stockholders may be less than the number of shares of common stock registered for resale by such Selling Stockholder in accordance with the Company’s obligations under the Registration Rights Agreements.

Unless otherwise noted, the business address of each of these shareholders is c/o Eterna Therapeutics, Inc., 1035 Cambridge Street, Suite 18A, Cambridge, MA 02141

Each Selling Stockholder and any of their respective pledgees, assignees and successors-in-interest may, from time to time, sell any or all of their securities covered hereby on the Nasdaq Capital Market or any other stock exchange, market or trading facility on which the securities are traded or in private transactions. These sales may be at fixed or negotiated prices. A Selling Stockholder may use any one or more of the following methods when selling the securities offered hereby:

The Selling Stockholders may also sell securities in accordance with Rule 144, if available, or pursuant to any available exemption from registration under the Securities Act rather than under this prospectus. The Selling Stockholders will act independently of us in making decisions with respect to the timing, manner and size of each sale. Such sales may be made on one or more exchanges or in the over-the-counter market or otherwise, at prices and under terms then prevailing or at prices related to the then current market price or in negotiated transactions.

In addition, a Selling Stockholder that is an entity may elect to make an in-kind distribution of securities to its members, partners or stockholders pursuant to the registration statement of which this prospectus is a part by delivering a prospectus with a plan of distribution. Such members, partners or stockholders would thereby receive freely tradeable securities pursuant to the distribution through a registration statement. To the extent a distributee is an affiliate of ours (or to the extent otherwise required by law), we may file a prospectus supplement in order to permit the distributees to use the prospectus to resell the securities acquired in the distribution. The Selling Stockholders also may transfer their respective securities in other circumstances, in which case the transferees, pledgees or other successors-in-interest will be the selling beneficial owners for purposes of this prospectus. Upon being notified by the Selling Stockholders that a donee, pledgee, transferee, other successor-in-interest intends to sell our securities, we will, to the extent required, promptly file a supplement to this prospectus to name specifically such person as a Selling Stockholder.

Broker-dealers engaged by the Selling Stockholders may arrange for other brokers-dealers to participate in sales. Broker-dealers may receive commissions or discounts from the Selling Stockholders (or, if any broker-dealer acts as agent for the purchaser of securities, from the purchaser) in amounts to be negotiated, but, except as set forth in a supplement to this Prospectus, in the case of an agency transaction not in excess of a customary brokerage commission in compliance with FINRA Rule 2121; and in the case of a principal transaction a markup or markdown in compliance with FINRA Rule 2121.

Subject to applicable law, in connection with the sale of the securities or interests therein, the Selling Stockholders may enter into hedging transactions with broker-dealers or other financial institutions, which may in turn engage in short sales of the securities in the course of hedging the positions they assume. Subject to applicable law, the Selling Stockholders may also sell securities short and deliver these securities to close out their short positions, or loan or pledge the securities to broker-dealers that in turn may sell these securities. The Selling Stockholders may also enter into option or other transactions with broker-dealers or other financial institutions or

create one or more derivative securities which require the delivery to such broker-dealer or other financial institution of securities offered by this prospectus, which securities such broker-dealer or other financial institution may resell pursuant to this prospectus (as supplemented or amended to reflect such transaction).

Any broker-dealers or agents that are involved in selling the securities offered hereby may be deemed to be “underwriters” within the meaning of the Securities Act in connection with such sales. In such event, any commissions received by such broker-dealers or agents and any profit on the resale of the securities purchased by them may be deemed to be underwriting commissions or discounts under the Securities Act. Each Selling Stockholder has informed the Company that it does not have any written or oral agreement or understanding, directly or indirectly, with any person to distribute the securities.

The Company is required to pay certain fees and expenses incurred by the Company incident to the registration of the securities. The Company has agreed to indemnify the Selling Stockholders against certain losses, claims, damages and liabilities, including liabilities under the Securities Act.

We agreed to keep this prospectus effective until the earlier of (i) the date on which the securities may be resold by the Selling Stockholders without registration and without regard to any volume or manner-of-sale limitations by reason of Rule 144 without the requirement for the Company to be in compliance with the current public information under Rule 144 under the Securities Act or any other rule of similar effect, (ii) all of the securities have been sold pursuant to this prospectus or Rule 144 under the Securities Act or any other rule of similar effect or (iii) the securities offered by this prospectus have been disposed of by the Selling Stockholders (or the other holders of Registrable Securities (as defined in the Registration Rights Agreements)). The resale securities will be sold only through registered or licensed brokers or dealers if required under applicable state securities laws. In addition, in certain states, the resale securities covered hereby may not be sold unless they have been registered or qualified for sale in the applicable state or an exemption from the registration or qualification requirement is available and is complied with.

Under applicable rules and regulations under the Exchange Act, any person engaged in the distribution of the resale securities may not, subject to certain exceptions, simultaneously engage in market making activities with respect to the common stock for the applicable restricted period, as defined in Regulation M, prior to the commencement of the distribution. In addition, the Selling Stockholders will be subject to applicable provisions of the Exchange Act and the rules and regulations thereunder, including Regulation M, which may limit the timing of purchases and sales of the common stock by the Selling Stockholders or any other person. We will make copies of this prospectus available to the Selling Stockholders and have informed them of the need to deliver a copy of this prospectus to each purchaser at or prior to the time of the sale (including by compliance with Rule 172 under the Securities Act).

Our common stock is listed on the Nasdaq Capital Market under the symbol “ERNA.” The transfer agent and registrar for the common stock is Computershare Trust Company, N.A.

The validity of the securities offered by this prospectus has been passed upon for us by Greenberg Traurig, LLP, New York, NY.

The audited consolidated financial statements as of and for the year ended December 31, 2022 of Eterna Therapeutics Inc. incorporated by reference in this prospectus and elsewhere in the registration statement have been so incorporated by reference in reliance upon the report of Grant Thornton LLP, independent registered public accountants, upon the authority of such firm as experts in accounting and auditing.

The audited consolidated financial statements as of and for the year ended December 31, 2021 of Eterna Therapeutics Inc. (formerly known as Brooklyn ImmunoTherapeutics, Inc.) incorporated by reference in this prospectus, have been so incorporated by reference in reliance upon the report of Marcum, LLP, independent registered public accounting firm, upon the authority of such firm as experts in accounting and auditing.

The SEC allows us to “incorporate by reference” information into this prospectus, which means that we can disclose important information to you by referring to those documents. We hereby “incorporate by reference” the documents listed below, which means that we are disclosing important information to you by referring you to those documents. The Registration Statement, including the exhibits, can be read at the SEC website referred to below under “Where You Can Find More Information.” The information that we file later with the SEC will automatically update and in some cases supersede this information. Specifically, we incorporate by reference the following documents or information filed with the SEC (other than, in each case, documents or information deemed to have been furnished and not filed in accordance with SEC rules):

In addition, all documents subsequently filed by us pursuant to Sections 13(a), 13(c), 14, or 15(d) of the Exchange Act (not including any information furnished under Item 2.02, 7.01, or 9.01 of Form 8-K or any other information that is identified as “furnished” rather than filed, which information is not incorporated by reference herein) after the initial filing date of the registration statement of which this prospectus is a part and prior to the effectiveness of the registration statement, as well as subsequent to the effectiveness of such registration statement and prior to the filing of a post-effective amendment which indicates that all securities offered have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference in the registration statement, of which this prospectus forms a part, and to be a part hereof from the date of filing of such documents.

Any statement contained in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of the registration statement, of which this prospectus forms a part, to the extent that a statement contained herein, or in any other subsequently filed document that also is deemed to be incorporated by reference herein, modifies or supersedes such statement. Any statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of the registration statement, of which this prospectus forms a part.

We will provide without charge to each person, including any beneficial owner, to whom a prospectus is delivered, upon written or oral request of that person, a copy of any and all of the information that has been incorporated by reference in this prospectus (excluding exhibits unless specifically incorporated by reference into those documents). Please direct requests to us at the following address:

You may also access these filings on our website at www.eternatx.com. Except for the specific incorporated documents listed above, no information available on or through our website shall be deemed to be incorporated in this prospectus or the registration statement of which it forms a part.

This prospectus is part of a registration statement we filed with the SEC and does not contain all the information set forth or incorporated by reference in the registration statement. Whenever a reference is made in this prospectus to any of our contracts, agreements, or other documents, the reference may not be complete and you should refer to the exhibits that are a part of the registration statement or the exhibits to the reports or other documents incorporated by reference into this prospectus for a copy of such contract, agreement, or other document. Because we are subject to the information and reporting requirements of the Exchange Act, we file annual, quarterly, and current reports, proxy statements, and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov.

Our website address is www.eternatx.com. The information contained on, or accessible through, our website is not incorporated into this prospectus and does not form a part hereof.

The following table sets forth the estimated expenses to be borne by the registrant in connection with the issuance and distribution of the securities being registered hereby.

Section 145(a) of the DGCL provides, in general, that a corporation may indemnify any person who was or is a party to 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), because he or she 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, partnership, joint venture, trust or other enterprise, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by the person in connection with such action, suit or proceeding, if he or she acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the corporation and, 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 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 procure 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, partnership, joint venture, trust or other enterprise, against expenses (including attorneys’ fees) actually and reasonably incurred by the person in connection with the defense or settlement of such action or suit if he or she acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the corporation, except that no indemnification shall be made with respect to any claim, issue or matter as to which he or she shall have been adjudged to be liable to the corporation unless and only to the extent that the Court of Chancery or other adjudicating court determines that, despite the adjudication of liability but in view of all of the circumstances of the case, he or she is fairly and reasonably entitled to indemnity for such expenses that the Court of Chancery or other adjudicating court shall deem proper.

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, partnership, joint venture, trust or other enterprise against any liability asserted against such person and incurred by such person in any such capacity, or arising out of his or her status as such, whether or not the corporation would have the power to indemnify the person against such liability under Section 145 of the DGCL.

Our certificate of incorporation provides that we will indemnify, in the manner and to the full extent permitted by law, any person (or the estate of 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, and whether civil, criminal, administrative, investigative or otherwise, by reason of the fact that such person is or was our director, officer, employee or agent, or is or was serving at our request as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise. Where required by law, the indemnification provided for shall be made only as authorized in the specific case upon a determination in the manner provided by law, that indemnification of the director, officer, employee or agent is proper under the circumstances. We may, to the full extent permitted by law, purchase and maintain insurance on behalf of any such person against any liability which may be asserted against him. To the full extent permitted by law, the indemnification provided shall include expenses (including attorneys’ fees) in any action,

suit or proceeding, or in connection with any appeal therein, judgments, fines and amounts paid in settlement, and in the manner provided by law any such expenses may be paid by us in advance of the final disposition of such action, suit or proceeding. The indemnification described herein does not limit our right to indemnify any other person for any such expense to the full extent permitted by law, nor is it exclusive of any other rights to which any person seeking indemnification from us may be entitled under any agreement, vote of stockholders or disinterested directors or otherwise, both as to action in his or her official capacity and as to action in another capacity while holding such office.

The board of directors has approved a form of indemnification agreement that has been executed by each of our directors and executive officers. In general, these agreements each provide that we will indemnify the director or executive officer to the fullest extent permitted by law for claims arising in his or her capacity as a director or executive officer of our company or in connection with their 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 executive officer makes a claim for indemnification and establish certain presumptions that are favorable to the director or executive officer. We also maintain a general liability insurance policy, which will cover certain liabilities of our directors and officers arising out of claims based on acts or omissions in their capacities as directors or officers.

The undersigned registrant hereby undertakes:

Pursuant to the requirements of the Securities Act of 1933, as amended, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Cambridge, Commonwealth of Massachusetts, on the 14th day of August, 2023.

KNOW ALL PERSONS BY THESE PRESENTS that each person whose signature appears below constitutes and appoints Matthew Angel and Sandra Gurrola, and each of them, his or her true and lawful attorneys-in-fact and agents, each 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, including post-effective amendments, to this registration statement, and any registration statement relating to the offering covered by this registration statement and filed pursuant to Rule 462(b) under the Securities Act of 1933, as amended, and to file the same, with exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that each of said attorneys-in-fact and agents or their substitute or substitutes may lawfully do or cause to be done by virtue hereof.

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