Sec Form 4 Filing - ABG Management Ltd. @ ProMIS Neurosciences Inc. - 2025-10-22

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person ABG Management Ltd. 2. Issuer Name and Ticker or Trading Symbol ProMIS Neurosciences Inc. [ PMN] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) #3902, 39/F, E TOWER,, 10 HARCOURT RD CTR 3. Date of Earliest Transaction (MM/DD/YY) 10/22/2025 (Street) HONG KONG, K3 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Option (right to buy) $ 0.45 10/22/2025 A 40,000 ( 1 ) 10/22/2035 Common Shares 40,000 $ 0 40,000 D ( 2 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other ABG Management Ltd. #3902, 39/F, E TOWER, 10 HARCOURT RD CTR HONG KONG, K3 X Ally Bridge MedAlpha Master Fund L.P. C/O MAPLES CORPORATE SERVICES LIMITED, P.O. BOX 309, UGLAND HOUSE, GRAND CAYMAN, E9 X Ally Bridge Group (NY) LLC 430 PARK AVENUE, 12TH FLOOR NEW YORK,, NY10022 X Yu Fan #3902, 39/F, E TOWER, 10 HARCOURT RD CTR HONG KONG, K3 X Alex Slanix Paul C/O PROMIS NEUROSCIENCES INC. SUITE 200, 1920 YONGE STREET TORONTO,, A6M4S 3E2 X Signatures ABG Management Ltd., By: /s/ Fan Yu, Director 10/24/2025 Signature of Reporting Person Date Ally Bridge MedAlpha Master Fund L.P., By: Ally Bridge Group (NY) LLC, its manager, By: ABG Management Ltd., its managing member, By: /s/ Fan Yu, Director 10/24/2025 Signature of Reporting Person Date Ally Bridge Group (NY) LLC, By: ABG Management Ltd., its managing member, By: /s/ Fan Yu, Director 10/24/2025 Signature of Reporting Person Date /s/ Fan Yu 10/24/2025 Signature of Reporting Person Date /s/ Max A. Milbury, Attorney-in-Fact for Slanix Paul Alex 10/24/2025 Signature of Reporting Person Date

Explanation of Responses:

( 1 )25% of the shares subject to this option vested on the date of grant and the remaining shares shall vest in thirty-six equal monthly installments thereafter, subject to the Reporting Person's continued service on each such vesting date. ( 2 )This option was granted to Slanix Alex, a director of the Issuer and an employee of Ally Bridge Group (NY) LLC, which manages the investments of Ally Bridge MedAlpha Master Fund L.P. Dr. Alex holds any equity-based compensation awarded to him for his service as a director of the Issuer for the benefit of Ally Bridge MedAlpha Master Fund L.P. Any proceeds from the sale of shares upon exercise of this award shall be remitted to Ally Bridge MedAlpha Master Fund L.P. The Reporting Person disclaims beneficial ownership of such securities for purposes of Section 16 except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that such securities are beneficially owned by him for Section 16 or any other purpose.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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