Exhibit 4.28

AMENDMENT NO. 2

TO THE

AGREEMENT OF MERGER AND PLAN OF REORGANIZATION

This Amendment is made as of February 17, 2025 (this “Amendment”) to the Agreement of Merger and Plan of Reorganization, dated November 4, 2024 (as previously amended on January 30, 2025, the “Agreement”), between Kadimastem Ltd., an Israeli publicly traded company limited by shares (“Kadimastem”), NLS Pharmaceutics Ltd., a corporation incorporated under the laws of Switzerland (the “NLS”), and NLS Pharmaceuticals (Israel) Ltd., an Israeli company (and together with Kadimastem and NLS, the “Parties”).

WHEREAS, the Parties are parties to the Agreement, and

WHEREAS, the Parties desire to amend the Agreement to clarify their intentions with respect to the terms of the terms thereof.

NOW, THEREFORE, for good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the parties agree as follows:

5.16 Parent Board Designee.

5.16.1 During the period (the “Zwyer Designee Period”) from the Closing Date until the date that is one year after the Closing Date, Parent shall not take action to remove, or recommend the removal of, Mr. Alexander Zwyer from the Parent’s board without cause therefor, and shall nominate for election and continue to recommend to its shareholders that Mr. Zwyer be elected to serve as a director on Parent’s board of directors; provided, however, that Parent’s obligation to appoint Mr. Zwyer to the Parent’s board of directors, shall terminate upon the expiration of the Zwyer Designee Period.

5.16.2 As a condition to the Mr. Zwyer’s appointment to Parent’s board of directors, Mr. Zwyer shall tender an irrevocable resignation that will be effective upon (1) the expiration of the Zwyer Designee Period and (2) the acceptance of such resignation by Parent’s board of directors. Parent’s board of directors will decide within 45 days of the expiration of the Zwyer Designee Period, through a process managed by the nominating and governance committee of Parent’s board of directors, whether to accept the resignation.

5.16.3 During the Zwyer Designee Period, Mr. Zwyer shall be entitled to all of the rights enjoyed by other non-employee directors of Parent, including receipt of information, reimbursement of expenses and coverage under applicable director and officer insurance policies. Further, Mr. Zwyer will immediately resign if he does not comply with or would disqualify Parent from complying with (i) applicable securities laws, (ii) contractual obligations to and rules of any market or exchange on which the Parent Common Stock is listed or quoted for trading on the date in question (including, without limitation, the NYSE American, the Nasdaq Capital Market, the Nasdaq Global Market, the Nasdaq Global Select Market, the New York Stock Exchange, or the OTC Bulletin Board or OTCQB Marketplace operated by OTC Markets Group, Inc. (or any successors to any of the foregoing)), and (iii) the criteria for directors set forth in the then current charter, if any, of the Parent’s nominating committee, and will not disqualify Parent from being able to conduct any public offering or private placement pursuant to either Rule 506 (b) or (c) and any “bad boy” provisions of any state securities laws.

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IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed by their respective authorized signatories as of the date first indicated above.