Company: APM
Filing Date: 2025-07-22
Form Type: 6-K
Source: 0001213900-25-066642
Chunk: 0

Company: Aptorum Group Ltd
Filing Date: 2025-07-22
Form: 6-K
Chunk 0
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<div align='center'>UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of July 2025

Commission File Number: 001-38764

Aptorum Group Limited

17 Hanover Square

London W1S 1BN, United Kingdom

(Address of principal executive office)</div>

Indicate by check mark
whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

<div align='center'>Form 20-F ☒ Form 40-F ☐</div>

Merger with DiamiR Biosciences Corp.

Aptorum Group Limited, a Cayman Islands exempted company with
limited liability (“Aptorum”, “APM,” “Aptorum Group” or the “Company”) and DiamiR Biosciences
Corp., a Delaware corporation (“DiamiR”), entered into an Agreement and Plan of Merger on July 14, 2025, (the “Merger
Agreement”), pursuant to which, among other matters, Aptorum will form a direct, wholly owned subsidiary in the state of Delaware
(“Merger Sub”), which will merge with and into DiamR, with DiamiR surviving as a wholly owned subsidiary of Aptorum , and
the surviving corporation of the merger with the Merger Sub (the “Merger”). Aptorum following the Merger is referred to herein
as the “Combined Company.”

Concurrently with the execution
of the Merger Agreement, DiamiR and Aptorum Therapeutics Limited, a wholly owned subsidiary of the Company (“Aptorum Therapeutics”),
entered into a management services agreement, pursuant to which, Aptorum Therapeutics shall pay a monthly service fee and reimburse expenses
to DiamiR in exchange for the officers and employees of DiamiR providing services to Aptorum Therapeutics to develop a diagnostic test
for early detection and monitoring of progression of glioblastoma until the earlier of the closing of the Merger or December 31, 2025.
In addition, concurrently with the execution of the Merger Agreement, DiamiR, DiamiR LLC, a wholly owned subsidiary of DiamiR, the Company
and Aptorum Therapeutics entered