Exhibit 10.3

AMENDMENT TO 

MANAGEMENT SERVICES AGREEMENT

This Amendment dated as of December 2, 2025 (the “Amendment”), is by and between DiamiR Biosciences Corp. a Delaware, U.S., incorporated company (the “Service Provider”) and Aptorum Therapeutics Limited (“Aptorum Therapeutics,” a Cayman Islands exempted company with limited liability, Service Provider and Aptorum Therapeutics, each a “Party” and collectively, the “Parties”).

BACKGROUND

WHEREAS, the Parties entered into that certain Management Services Agreement dated July 14, 2025 (the “MSA”). Capitalized terms used but not otherwise defined herein shall have the meanings ascribed to them in the MSA.

WHEREAS, the Parties seek to extend the term of the MSA and increase the total monthly Management Service Fee payable as set forth in this Amendment;

WHEREAS, this Amendment constitutes a written agreement signed by the necessary parties in order to effectuate the amendments to the MSA specified below.

NOW, THEREFORE, in consideration of the foregoing and the respective covenants and agreements set forth herein, the parties hereto agree as follows:

“The Agreement shall commence on the date hereof and shall continue until the earlier (i) the closing of the transaction(s) contemplated by the Definitive Agreements; or (ii) March 31, 2026.”

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