EX-3.4

Exhibit 3.4

AMENDED AND RESTATED

CERTIFICATE OF INCORPORATION

AKTIS ONCOLOGY, INC.

Aktis Oncology, Inc., a corporation organized and existing under the laws of the State of Delaware (the “Corporation”), hereby certifies as follows:

1. The name of the Corporation is Aktis Oncology, Inc. The date of the filing of its original Certificate of Incorporation with the Secretary of State of the State of Delaware was August 18, 2020 (the “Original Certificate”). The name under which the Corporation filed the Original Certificate was HotKnot Therapeutics, Inc.

2. This Amended and Restated Certificate of Incorporation (the “Certificate”) amends, restates and integrates the provisions of the Sixth Amended and Restated Certificate of Incorporation that was filed with the Secretary of State of the State of Delaware on [•], 2025 (the “Sixth Amended and Restated Certificate”), and was duly adopted in accordance with the provisions of Sections 228, 242 and 245 of the General Corporation Law of the State of Delaware (the “DGCL”).

3. The text of the Sixth Amended and Restated Certificate is hereby amended and restated in its entirety to provide as herein set forth in full.

ARTICLE I

The name of the Corporation is Aktis Oncology, Inc.

ARTICLE II

The address of the Corporation’s registered office in the State of Delaware is c/o The Corporation Trust Company, 1209 Orange Street in the City of Wilmington, County of New Castle, 19801. The name of its registered agent at such address is The Corporation Trust Company.

ARTICLE III

The purpose of the Corporation is to engage in any lawful act or activity for which corporations may be organized under the DGCL.

ARTICLE IV

CAPITAL STOCK

The total number of shares of capital stock which the Corporation shall have authority to issue is five hundred million (500,000,000), comprised of three classes as follows: (i) four hundred ninety million (490,000,000) shares shall be a class designated as common stock, par value $0.0001 per share (the “Common Stock”), (ii) ten million (10,000,000) shares shall be a class designated as Class A common stock, par value $0.0001 per share (the “Class A Common Stock”) and (iii) ten million (10,000,000) shares shall be a class designated as preferred stock, par value $0.0001 per share (the “Preferred Stock”).

Except as otherwise provided in any certificate of designations of any series of Preferred Stock, the number of authorized shares of Common Stock, Class A Common Stock or Preferred Stock may be increased or decreased (but not below the number of shares of such class then outstanding) without the separate class vote of the holders of the Common Stock, Class A Common Stock or Preferred Stock, respectively, otherwise provided by Section 242(b)(2) of the DGCL.

The powers, preferences and rights of, and the qualifications, limitations and restrictions upon, each class or series of stock shall be determined in accordance with, or as set forth below in, this Article IV.

A. COMMON STOCK; CLASS A COMMON STOCK

Subject to all the rights, powers and preferences of the Preferred Stock and except as provided by law or in this Certificate (or in any certificate of designations of any series of Preferred Stock):

(a) the holders of the Common Stock shall have the exclusive right to vote for the election of directors of the Corporation (the “Directors”) and on all other matters requiring stockholder action, each outstanding share entitling the holder thereof to one vote on each matter properly submitted to the stockholders of the Corporation for their vote; provided, however, that, except as otherwise required by law, holders of Common Stock, as such, shall not be entitled to vote on any amendment to this Certificate (or on any amendment to a certificate of designations of any series of Preferred Stock) that alters or changes the powers, preferences, rights or other terms of one or more outstanding series of Class A Common Stock or Preferred Stock if the holders of such affected series of Class A Common Stock or Preferred Stock are entitled to vote, either separately or together with the holders of one or more other such series, on such amendment pursuant to this Certificate (or pursuant to a certificate of designations of any series of Preferred Stock) or pursuant to the DGCL;

(b) the Class A Common Stock shall be non-voting shares, and the holders of the Class A Common Stock, as such, shall not be entitled to vote on any matter, except as required by law or as otherwise provided for in this Certificate;

(c) shares of Common Stock and Class A Common Stock shall be treated equally, identically and ratably, on a per share basis, with respect to any dividends or distributions as may be declared and paid from time to time by the Board of Directors out of any assets of the Corporation legally available therefor; provided, however, that in the event a dividend is paid in the form of shares of Common Stock or Class A Common Stock (or rights to acquire, or securities convertible into or exchangeable for, such shares), then holders of Common Stock shall be entitled to receive shares of Common Stock (or rights to acquire, or securities convertible into or exchangeable for, such shares, as the case may be) and holders of Class A Common Stock shall be entitled to receive shares of Class A Common Stock (or rights to acquire, or securities convertible into or exchangeable for, such shares, as the case may be), with holders of shares of Common Stock and Class A Common Stock receiving, on a per share basis, an identical number of shares of Common Stock or Class A Common Stock (or rights to acquire, or securities convertible into or exchangeable for, such shares, as the case may be), as applicable. Notwithstanding the foregoing, the Board of Directors may pay or make a disparate dividend or distribution per share of Common Stock or Class A Common Stock (whether in the amount of such dividend or distribution payable per share, the form in which such dividend or distribution is payable, the timing of the payment, or otherwise) if such disparate dividend or distribution is approved in advance by the affirmative vote of the holders of a majority of the outstanding shares of Common Stock and Class A Common Stock, each voting separately as a class;

(d) upon the voluntary or involuntary liquidation, dissolution or winding up of the Corporation, the net assets of the Corporation shall be distributed pro rata to the holders of the Common Stock and Class A Common Stock, treated equally and identically;

(e) in connection with any merger or consolidation of the Corporation with or into any other entity, or of any conversion or domestication of the Corporation, shares of Common Stock and shares of Class A Common Stock shall be treated equally, identically and ratably, on a per share basis, with respect to any consideration into which such shares are converted or any other consideration paid or otherwise distributed to stockholders of the Corporation in the merger, consolidation, conversion or domestication, unless different treatment of the shares of each class is approved by the affirmative vote of the holders of a majority of the outstanding shares of Common Stock and Class A Common Stock, each voting separately as a class; and

(f) shares of Common Stock or Class A Common Stock may not be subdivided, combined or reclassified unless the shares of each of the other class are concurrently therewith proportionately subdivided, combined or reclassified in a manner that maintains the same proportionate equity ownership between the holders of the outstanding Common Stock and Class A Common Stock on the record date for such subdivision, combination or reclassification; provided, however, that shares of one such class may be subdivided, combined or reclassified in a different or disproportionate manner if such subdivision, combination or reclassification is approved in advance by the affirmative vote of the holders of a majority of the outstanding shares of Common Stock and Class A Common Stock, each voting separately as a class.

B. CONVERSION OF CLASS A COMMON STOCK

1. Each holder of shares of Class A Common Stock shall have the right to convert each share of Class A Common Stock held by such holder into one share of Common Stock at such holder’s election, which shall be made upon written notice delivered to the Corporation, provided that, the shares of Class A Common Stock may only be converted into shares of Common Stock during such time or times as immediately prior to or as a result of such conversion would not result in the holder(s) thereof beneficially owning (for purposes of Section 13(d) of the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder (collectively, the “Exchange Act”)), when aggregated with affiliates, persons acting as a Section 13(d) “group” together with such holder or an affiliate thereof, and any other persons whose beneficial ownership of the Corporation’s Common Stock is required to be aggregated with the holder’s or its affiliate’s beneficial ownership for purposes of Section 13(d) of the Exchange Act, in excess of the Beneficial Ownership Limitation. The “Beneficial Ownership Limitation” means initially 4.99% of any class of securities of the Corporation registered under the Exchange Act, which percentage may be increased or decreased by a holder of outstanding shares of Class A Common Stock to such other percentage not in excess of 19.99% as such holder may designate in writing upon notice to the Corporation, provided, however, that any such increase or decrease shall only be applicable to such holder and any such increase shall not become effective until the sixty-first (61^st) day after such notice is delivered to the Corporation.

2. In order for a holder of Series A Common Stock to voluntarily convert shares of Class A Common Stock to Common Stock, such holder shall deliver written notice to the transfer agent (or by the Corporation if the Corporation serves as its own transfer agent) of the Corporation that such holder elects to convert all or any number of the shares of the Class A Common Stock to Common Stock. Such notice shall state such holder’s name or the names of the nominees in which such holder wishes the certificate or certificates for shares of Common Stock to be issued. The close of business on the date of receipt by the transfer agent (or by the Corporation if the Corporation serves as its own transfer agent) of such notice shall be the time of conversion, and the shares of Common Stock issuable upon conversion of the Class A Common Stock set forth in the notice shall be deemed to be outstanding of record as of such date. If the conversion would result in the issuance of any fractional share of Common Stock or Class A Common Stock, the Corporation shall, in lieu of issuing a fractional share, after aggregating all fractional shares of Common Stock or Class A Common Stock, as applicable, that a holder would otherwise be entitled to receive, pay cash to such holder equal to the product of such fraction multiplied by the fair market value of one share of Common Stock or Class A Common Stock, as applicable.

3. The one-to-one conversion ratio for the conversion of the Class A Common Stock into Common Stock shall in all events be equitably adjusted in the event of any recapitalization of the Corporation by means of a stock dividend on, or a stock split or combination of, outstanding Common Stock or Class A Common Stock, or in the event of any merger, consolidation or other reorganization of the Corporation with another corporation.

4. The Corporation shall at all times reserve and keep available out of its authorized but unissued shares of Common Stock, solely for the purpose of effecting the conversion of the shares of Class A Common Stock, such number of its shares of Common Stock as shall from time to time be sufficient to effect the conversion of all outstanding shares of Class A Common Stock.

5. If any shares of Class A Common Stock shall be converted pursuant to this Article IV(B), the shares so converted shall be retired and returned to the authorized but unissued shares of Class A Common Stock.

C. PREFERRED STOCK

The Board of Directors or any authorized committee thereof is expressly authorized, to the fullest extent permitted by law, to provide by resolution or resolutions for, out of the undesignated shares of Preferred Stock, the issuance of the shares of Preferred Stock in one or more series of such stock, and by filing a certificate of designations pursuant to applicable law of the State of Delaware, to establish or change from time to time the number of shares of each such series, and to fix the designations, powers, including voting powers, full or limited, or no voting powers, preferences and the relative, participating, optional or other special rights of the shares of each series and any qualifications, limitations and restrictions thereof.

ARTICLE V

STOCKHOLDER ACTION

1. Action without Meeting. Any action required or permitted to be taken by the stockholders of the Corporation at any annual or special meeting of stockholders of the Corporation must be effected at a duly called annual or special meeting of stockholders and may not be taken or effected by a written consent of stockholders in lieu thereof; provided, however, that any action required or permitted to be taken by the holders of Preferred Stock, voting separately as a series or separately as a class with one or more other such series, may be taken without a meeting, without prior notice and without a vote, to the extent expressly so provided in the resolutions creating such series of Preferred Stock.

2. Special Meetings. Except as otherwise required by statute and subject to the rights, if any, of the holders of any series of Preferred Stock, special meetings of the stockholders of the Corporation may be called only by the Board of Directors, and special meetings of stockholders may not be called by any other person or persons. Only those matters set forth in the notice of the special meeting may be considered or acted upon at a special meeting of stockholders of the Corporation.

ARTICLE VI

DIRECTORS

1. General. The business and affairs of the Corporation shall be managed by or under the direction of the Board of Directors except as otherwise provided herein or required by law.

2. Number of Directors; Term of Office. The number of Directors of the Corporation shall be fixed solely and exclusively by resolution duly adopted from time to time by the Board of Directors. The Directors, other than those who may be elected by the holders of any series of Preferred Stock, shall be classified, with respect to the term for which they severally hold office, into three classes. The term of office of the initial Class I directors shall expire at the first annual meeting of stockholders following the closing of the Corporation’s sale of a class of its capital stock to the public pursuant to a registration statement on Form S-1 under the Securities Act of 1933, as amended (the “IPO Time”). The term of office of the initial Class II directors shall expire at the second annual meeting of stockholders following the IPO Time. The term of office of the initial Class III directors shall expire at the third annual meeting of stockholders following the IPO Time. The Board of Directors is authorized to assign members of the Board of Directors already in office to such classes at the time the classification becomes effective. At each annual meeting of stockholders, Directors elected to succeed those Directors whose terms expire shall be elected for a term of office to expire at the third succeeding annual meeting of stockholders after their election. Notwithstanding the foregoing, the Directors elected to each class shall hold office until their successors are duly elected and qualified or until their earlier resignation, death or removal; provided, however, that if no successor is being nominated for a director whose term is expiring at an annual meeting and the size of the Board of Directors being reduced at such annual meeting, such Director’s term shall end at such annual meeting and such Director shall not hold over until a successor is elected and qualified. Election of Directors need not be by written ballot unless the Bylaws of the Corporation (as amended and/or restated, the “Bylaws”) so provide.

Notwithstanding the foregoing, whenever, pursuant to the provisions of Article IV of this Certificate, the holders of any one or more series of Preferred Stock shall have the right, voting separately as a series or together with holders of other such series, to elect Directors at an annual or special meeting of stockholders, the election, term of office, filling of vacancies and other features of such directorships shall be governed by the terms of this Certificate and any certificate of designations applicable to such series. During any period when the holders of any series of Preferred Stock, voting separately as a series or together with one or more series, have the right to elect additional Directors, then upon commencement and for the duration of the period during which such right continues: (i) the then otherwise total authorized number of Directors shall automatically be increased by such specified number of Directors, and the holders of such Preferred Stock shall be entitled to elect the additional Directors so provided for or fixed pursuant to said provisions, and (ii) each such additional Director shall serve until such Director’s successor shall have been duly elected and qualified, or until such Director’s right to hold such office terminates pursuant to said provisions, whichever occurs earlier, subject to his or her earlier death, resignation, disqualification or removal. Except as otherwise provided by the

Board of Directors in the resolution or resolutions establishing such series, whenever the holders of any series of Preferred Stock having such right to elect additional Directors are divested of such right pursuant to the provisions of such stock, the terms of office of all such additional Directors elected by the holders of such stock, or elected to fill any vacancies resulting from the death, resignation, disqualification or removal of such additional Directors, shall forthwith terminate (in which case each such Director thereupon shall cease to be qualified as, and shall cease to be, a Director) and the total authorized number of Directors shall automatically be reduced accordingly.

3. Vacancies and Newly Created Directorships. Subject to the rights, if any, of the holders of any series of Preferred Stock to elect Directors and to fill vacancies in the Board of Directors relating thereto, any and all vacancies in the Board of Directors, however occurring, including, without limitation, by reason of an increase in the size of the Board of Directors, or the death, resignation, disqualification or removal of a Director, shall be filled solely and exclusively by the affirmative vote of a majority of the remaining Directors then in office, even if less than a quorum of the Board of Directors, and not by the stockholders. Any Director appointed in accordance with the preceding sentence shall hold office for the remainder of the full term of the class of Directors in which the new directorship was created or the vacancy occurred and until such Director’s successor shall have been duly elected and qualified or until his or her earlier resignation, death or removal. Subject to the rights, if any, of the holders of any series of Preferred Stock to elect Directors, when the number of Directors is increased or decreased, the Board of Directors shall, subject to Article VI.3 hereof, determine the class or classes to which the increased or decreased number of Directors shall be apportioned; provided, however, that no decrease in the number of Directors shall shorten the term of any incumbent Director. In the event of a vacancy in the Board of Directors, the remaining Directors, except as otherwise provided by law, shall exercise the powers of the full Board of Directors until the vacancy is filled.

4. Removal. Subject to the rights, if any, of any series of Preferred Stock to elect Directors and to remove any Director whom the holders of any such series have the right to elect, any Director (including persons elected by Directors to fill vacancies in the Board of Directors) may be removed from office (i) for so long as the Board of Directors is classified, only for cause and (ii) only by the affirmative vote of the holders not less than two-thirds (2/3) of the voting power of the outstanding shares of capital stock then entitled to vote thereon.

ARTICLE VII

LIMITATION OF LIABILITY

1. Directors. To the fullest extent permitted by the DGCL, a Director of the Corporation shall not be personally liable to the Corporation or its stockholders for monetary damages for breach of his or her fiduciary duty as a Director, except for liability (a) for any breach of the Director’s duty of loyalty to the Corporation or its stockholders, (b) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (c) under Section 174 of the DGCL or (d) for any transaction from which the Director derived an improper personal benefit. If the DGCL is amended after the effective date of this Certificate to authorize corporate action further eliminating or limiting the personal liability of Directors, then the liability of a Director of the Corporation shall be eliminated or limited to the fullest extent permitted by the DGCL, as so amended.

2. Officers. To the fullest extent permitted by the DGCL, an Officer (as defined below) of the Corporation shall not be personally liable to the Corporation or its stockholders for monetary damages for breach of his or her fiduciary duty as an officer of the Corporation, except for liability (a) for any breach of the Officer’s duty of loyalty to the Corporation or its stockholders, (b) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (c) for any transaction from which the Officer derived an improper personal benefit, or (d) arising from any claim brought by or in the right of the Corporation. If the DGCL is amended after the effective date of this Certificate to authorize corporate action further eliminating or limiting the personal liability of Officers, then the liability of an Officer of the Corporation shall be eliminated or limited to the fullest extent permitted by the DGCL, as so amended. For purposes of this Article VII, “Officer” shall have the meaning ascribed to that term in Section 102(b)(7) of the DGCL.

3. Amendment or Modification. Any amendment, repeal or modification of this Article VII or amendment to the DGCL, shall not adversely affect any right or protection existing at the time of such amendment, repeal or modification with respect to any acts or omissions occurring before such amendment, repeal or modification of a person serving as a Director or Officer, as applicable, at the time of such amendment, repeal or modification.

ARTICLE VIII

AMENDMENT OF BYLAWS

1. Amendment by Directors. Except as otherwise provided by law, the Bylaws may be amended or repealed by the Board of Directors.

2. Amendment by Stockholders. Subject to the rights, if any, of any series of Preferred Stock, the Bylaws may be amended or repealed at any annual meeting of stockholders, or special meeting of stockholders called for such purpose, by the affirmative vote of not less than two-thirds (2/3) of the outstanding voting power of the shares of capital stock entitled to vote thereon, voting together as a single class; provided, however, that if the Board of Directors recommends that stockholders approve such amendment or repeal at such meeting of stockholders, such amendment or repeal shall only require the affirmative vote of the majority of outstanding voting power of the shares of capital stock entitled to vote thereon, voting together as a single class.

ARTICLE IX

AMENDMENT OF CERTIFICATE OF INCORPORATION; SEVERABILITY

The Corporation reserves the right to amend or repeal this Certificate in the manner now or hereafter prescribed by statute and this Certificate, and all rights conferred upon stockholders herein are granted subject to this reservation.

If any provision or provisions of this Certificate shall be held to be invalid, illegal or unenforceable as applied to any circumstance for any reason whatsoever, the validity, legality and enforceability of such provisions in any other circumstance and of the remaining provisions of this Certificate (including, without limitation, each portion of any paragraph of this Certificate containing any such provision held to be invalid, illegal or unenforceable that is not itself held to be invalid, illegal or unenforceable) shall not, to the fullest extent permitted by applicable law, in any way be affected or impaired thereby.

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THIS AMENDED AND RESTATED CERTIFICATE OF INCORPORATION is executed as of this ____ day of __________, 2026.


AKTIS ONCOLOGY, INC.

By:
Name:
Title: