# EDGAR Filing Document

**Accession Number:** 0001374339
**File Stem:** 0001558370-25-011399
**Filing Date:** 2025-8
**Character Count:** 38923
**Document Hash:** cccc38c9c90d0270ae0f7425acc7bcb6
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001558370-25-011399.hdr.sgml**: 20250813

**ACCESSION NUMBER**: 0001558370-25-011399

**CONFORMED SUBMISSION TYPE**: S-8

**PUBLIC DOCUMENT COUNT**: 15

**FILED AS OF DATE**: 20250813

**DATE AS OF CHANGE**: 20250813

**EFFECTIVENESS DATE**: 20250813

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** ProMIS Neurosciences Inc.
- **CENTRAL INDEX KEY:** 0001374339
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** Z4
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** S-8
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-289579
- **FILM NUMBER:** 251212385

**BUSINESS ADDRESS:**
- **STREET 1:** SUITE 200, 1920 YONGE STREET
- **CITY:** TORONTO
- **STATE:** A6
- **ZIP:** M4S 3E2
- **BUSINESS PHONE:** 416-847-6898

**MAIL ADDRESS:**
- **STREET 1:** SUITE 200, 1920 YONGE STREET
- **CITY:** TORONTO
- **STATE:** A6
- **ZIP:** M4S 3E2

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** AMORFIX LIFE SCIENCES LTD
- **DATE OF NAME CHANGE:** 20060831

As filed with the Securities and Exchange Commission on August 13, 2025

Registration No. 333-

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**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

**FORM S-8**

**REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933**

**PROMIS NEUROSCIENCES INC.**

(Exact name of Registrant as specified in its charter)

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| | |
|:---|:---|
| **Canada**<br>(State or other jurisdiction of<br>incorporation or organization) | **98-0647155**<br>(I.R.S. Employer<br>Identification No.) |
| **Suite 200, 1920 Yonge Street,**<br>**Toronto, Ontario**<br>(Address of Principal Executive Offices) | **M4S 3E2**<br>(Zip Code) |

---

**PROMIS NEUROSCIENCES INC. 2015 STOCK OPTION PLAN**

**PROMIS NEUROSCIENCES INC. 2025 STOCK OPTION AND INCENTIVE PLAN**

(Full title of the plan)

**CT Corporation System**

**1015 15th Street N.W., Suite 1000**

**Washington, D.C., 20005**

(Name and address of agent for service)

**(416) 847-6898**

(Telephone number, including area code, of agent for service)

Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Securities Exchange Act of 1934, as amended.

Large accelerated filer ☐ Accelerated filer ☐ <br> Non-accelerated filer&nbsp;&nbsp;&nbsp;&nbsp;☒ Smaller reporting company ☒ <br> Emerging growth company ☒

If an emerging growth company, indicate by check mark if the Registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act of 1933, as amended.&nbsp;&nbsp;&nbsp;&nbsp;☐

------

**Explanatory Note**

This Registration Statement on Form S-8 (this "**Registration Statement**") is filed by ProMIS Neurosciences Inc., a corporation continued under the *Business Corporations Act* (Ontario) (the "**Registrant**"), to register 5,083,128 common shares, no par value per share ("**Common Shares**"), which consist of (i) 2,136,409 Common Shares reserved for issuance under the Registrant's 2015 Stock Option Plan, as amended (the "**2015 Plan**") and (ii) 2,946,719 Common Shares newly reserved for issuance under the Registrant's 2025 Stock Option and Incentive Plan (the "**2025 Plan**"), which was approved by the Registrant's Board of Directors on April 28, 2025 and by its stockholders on June 12, 2025. The 2025 Plan, which became effective upon the stockholders' approval, replaces the 2015 Plan. No further awards will be made under the 2015 Plan, but the 2015 Plan will continue to govern awards previously granted under it.

The Registrant previously registered 1,439,105 Common Shares under the 2015 Plan pursuant to a Registration Statement on [Form S-8 (File No. 333-267319)](https://www.sec.gov/Archives/edgar/data/1374339/000110465922098254/tm2224954d1_s8.htm) filed with the Securities and Exchange Commission (the "**SEC**") on September 7, 2022 (the "**Original Filing**"). The contents of the Original Filing, as updated by the information set forth herein, are incorporated by reference into this Registration Statement pursuant to General Instruction E of Form S-8.

**Part I — Information Required in the Section 10(a) Prospectus**

Item 1. <u>Plan Information</u>.

The documents containing the information specified in "Item 1. Plan Information" of Form S-8 will be sent or given to participants, as specified by Rule 428(b)(1) under the Securities Act of 1933 (the "**Securities Act**"). Such documents are not required to be, and are not, filed with the SEC either as part of this registration statement or as a prospectus or prospectus supplement pursuant to Rule 424 under the Securities Act. These documents and the documents incorporated by reference in this registration statement pursuant to Item 3 of Part II of Form S-8, taken together, constitute a prospectus that meets the requirements of Section 10(a) of the Securities Act.

**Part II — Information Required in the Registration Statement**

Item 3. <u>Incorporation of Documents by Reference</u>.

This Registration Statement incorporates by reference the documents set forth below that have been previously filed with the SEC:

● [our Annual Report on Form 10-K for the year ended December 31, 2024, filed with the SEC on March 31, 2025](https://www.sec.gov/ix?doc=/Archives/edgar/data/1374339/000155837025004068/pmn-20241231x10k.htm) ;

● the information specifically incorporated by reference into our [Annual Report on Form 10-K for the year ended December 31, 2024](https://www.sec.gov/ix?doc=/Archives/edgar/data/1374339/000155837025004068/pmn-20241231x10k.htm) from our [Definitive Proxy Statement on Schedule 14A, filed with the SEC on April 29, 2025](https://www.sec.gov/ix?doc=/Archives/edgar/data/1374339/000155837025005871/pmn-20250612xdef14a.htm) ;

● our Quarterly Reports on Form 10-Q for the fiscal quarter ended March 31, 2025, filed with the SEC on [May 12, 2025](https://www.sec.gov/ix?doc=/Archives/edgar/data/1374339/000155837025007255/pmn-20250331x10q.htm) , and for the fiscal quarter ended June 30, 2025, filed with the SEC on [August 13, 2025](https://www.sec.gov/ix?doc=/Archives/edgar/data/1374339/000155837025011299/pmn-20250630x10q.htm) ;

● our Current Reports on Form 8-K filed with the SEC on [January 8, 2025](https://www.sec.gov/ix?doc=/Archives/edgar/data/1374339/000155837025000075/pmn-20250103x8k.htm) , [January 10, 2025](https://www.sec.gov/ix?doc=/Archives/edgar/data/1374339/000155837025000095/pmn-20250110x8k.htm) , [February 19, 2025](https://www.sec.gov/ix?doc=/Archives/edgar/data/1374339/000155837025001158/pmn-20250214x8k.htm) , [June 13, 2025](https://www.sec.gov/ix?doc=/Archives/edgar/data/1374339/000155837025008600/pmn-20250612x8k.htm) , [July 7, 2025](https://www.sec.gov/ix?doc=/Archives/edgar/data/1374339/000155837025009112/pmn-20250703x8k.htm) , [July 22, 2025](https://www.sec.gov/ix?doc=/Archives/edgar/data/1374339/000155837025009352/pmn-20250721x8k.htm) , [July 22, 2025](https://www.sec.gov/ix?doc=/Archives/edgar/data/1374339/000155837025009380/pmn-20250722x8k.htm) , and [July 28, 2025](https://www.sec.gov/ix?doc=/Archives/edgar/data/1374339/000155837025009636/pmn-20250728x8k.htm) ;

● the description of our capital stock set forth in our Registration Statement on Form 10-12B filed with the SEC on [June 22, 2022](https://www.sec.gov/Archives/edgar/data/1374339/000110465922073200/tm229830d4_1012b.htm) , as amended, as supplemented by [Exhibit 4.4](https://www.sec.gov/Archives/edgar/data/1374339/000155837025004068/pmn-20241231xex4d4.htm) of our Annual Report on Form 10-K for the fiscal year ended December 31, 2024, together with any amendment or report filed with the SEC for the purpose of updating such description.

------

All documents filed by the Registrant pursuant to Section 13(a) or 15(d) of the United States Securities Exchange Act of 1934, as amended (the "**Exchange Act**"), subsequent to the date of this Registration Statement and prior to the filing of a post-effective amendment to this Registration Statement which indicates that all securities offered hereby have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference into this registration statement and to be a part hereof commencing on the respective dates on which such documents are filed.

Item 4. <u>Description of Securities</u>.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Not applicable.

Item 5. <u>Interests of Named Experts and Counsel</u>.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Not applicable.

Item 6. <u>Indemnification of Directors and Officers</u>.

Under the *Business Corporations Act* (Ontario) (the "**OBCA**"), the Registrant may indemnify its current or former directors or officers or another individual who acts or acted at its request as a director or officer, or an individual acting in a similar capacity, of another entity, against all costs, charges and expenses, including an amount paid to settle an action or satisfy a judgment, reasonably incurred by the individual in respect of any civil, criminal, administrative, investigative or other proceeding in which the individual is involved because of his or her association with the Registrant or another entity. The OBCA also provides that the Registrant may advance money to a director, officer or other individual for costs, charges and expenses reasonably incurred in connection with such a proceeding; provided that such individual shall repay the money if the individual does not fulfill the conditions described below.

However, indemnification is prohibited under the OBCA unless the individual:

● acted honestly and in good faith with a view to the Registrant's best interests, or the best interests of the other entity for which the individual acted as director or officer or in a similar capacity at the Registrant's request; and

● if the matter is a criminal or administrative action or proceeding that is enforced by a monetary penalty, the individual had reasonable grounds for believing that his or her conduct was lawful.

The Registrant's by-laws provide it may indemnify, subject to the OBCA, each of its current directors or officers or former directors or officers of the Registrant or of a corporation of which the Registration is or was a shareholder or creditor and the heirs and legal representatives of any such person against all costs, charges and expenses, including an amount paid to settle an action or satisfy a judgment, reasonably incurred by him or them in respect of any civil, criminal or administrative action or proceeding to which he is or they are made a party by reason of his being or having been a director or officer of the Registrant or a director or officer of such corporation, including any action brought by the Registrant or any such corporation.

The Registrant maintains insurance policies relating to certain liabilities that its directors and officers may incur in such capacity.

Item 7. <u>Exemption from Registration Claimed</u>.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Not applicable.

------

Item 8. <u>Exhibits</u>.

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| | |
|:---|:---|
| **Exhibit No.** | **Description of Exhibit**  |
| 3.1  | [Articles (incorporated herein by reference to Exhibit 3.1 to the Registrant's Form 10 Registration Statement filed June 22, 2022, as amended).](https://www.sec.gov/Archives/edgar/data/1374339/000110465922073200/tm229830d4_ex3-1.htm) |
| 3.1.1  | [Certificate of Amendment to the Articles dated July 8, 2015 (incorporated herein by reference to Exhibit 3.1.1 to the Registrant's Form 10 Registration Statement filed June 22, 2022, as amended).](https://www.sec.gov/Archives/edgar/data/1374339/000110465922073200/tm229830d4_ex3-1d1.htm) |
| 3.1.2  | [Certificate of Amendment to the Articles dated June 17, 2022 (incorporated herein by reference to Exhibit 3.1.2 to the Registrant's Form 10 Registration Statement filed June 22, 2022, as amended).](https://www.sec.gov/Archives/edgar/data/1374339/000110465922073200/tm229830d4_ex3-1d2.htm) |
| 3.1.3  | [Certificate of Amendment to the Articles dated June 21, 2022 (incorporated herein by reference to Exhibit 3.1.3 to the Registrant's Form 10 Registration Statement filed June 22, 2022, as amended).](https://www.sec.gov/Archives/edgar/data/1374339/000110465922076352/tm229830d7_ex3-1d3.htm) |
| 3.1.4 | [Articles of Continuance dated June 29, 2023 (incorporated herein by reference to Exhibit 3.1 to the Registrant's Current Report on Form 8-K filed July 14, 2023, as amended).](https://www.sec.gov/Archives/edgar/data/1374339/000155837023011879/pmn-20230713xex3d1.htm) |
| 3.1.5 | [Certificate of Amendment to the Articles dated December 4, 2023. (incorporated by reference to Exhibit 3.1 to the Registrant's Current Report on Form 8-K, filed December 8, 2023, as amended).](https://www.sec.gov/Archives/edgar/data/1374339/000155837023019700/pmn-20231204xex3d1.htm) |
| 3.2  | [Amended and Restated By-law No. 1. (incorporated herein by reference to Exhibit 3.2 to the Registrant's Form 10 Registration Statement filed June 22, 2022, as amended).](https://www.sec.gov/Archives/edgar/data/1374339/000110465922073200/tm229830d4_ex3-2.htm) |
| 3.2.1  | [By-law No. 2. (incorporated herein by reference to Exhibit 3.2.1 to the Registrant's Form 10 Registration Statement filed June 22, 2022, as amended).](https://www.sec.gov/Archives/edgar/data/1374339/000110465922073200/tm229830d4_ex3-2d1.htm) |
| 3.2.2 | [Amended and Restated By-law No. 1. (incorporated by reference to Exhibit 3.2 to the Registrant's Current Report on Form 8-K filed July 14, 2023, as amended).](https://www.sec.gov/Archives/edgar/data/1374339/000155837023011879/pmn-20230713xex3d2.htm) |
| 3.2.3 | [Amended and Restated By-law No. 2. (incorporated by reference to Exhibit 3.3 to the Registrant's Current Report on Form 8-K filed July 14, 2023, as amended).](https://www.sec.gov/Archives/edgar/data/1374339/000155837023011879/pmn-20230713xex3d3.htm) |
| 4.1 | [ProMIS Neurosciences Inc. 2015 Stock Option Plan (incorporated by reference to Exhibit 10.38 to the Registrant's Form S-1 Registration Statement, filed November 1, 2022, as amended).](https://www.sec.gov/Archives/edgar/data/1374339/000110465922113573/pmn-20220630xex10d38.htm) |
| 4.2 | [ProMIS Neuroscience Inc. 2025 Stock Option and Incentive Plan and forms of award agreements thereunder (incorporated by reference to Exhibit 10.1 to the Registrant's Form 10-Q Quarterly Report, filed August 13, 2025, as amended).](https://www.sec.gov/Archives/edgar/data/1374339/000155837025011299/pmn-20250630xex10d1.htm) |
| 5.1\* | [Opinion of McMillan LLP.](pmn-20250813xex5d1.htm) |
| 23.1\* | [Consent of Baker Tilly US, LLP.](pmn-20250813xex23d1.htm) |
| 23.2 | [Consent of McMillan LLP (contained in Exhibit 5.1 hereto).](pmn-20250813xex5d1.htm) |
| 24.1 | [Powers of Attorney (included on the signature page of this registration statement).](#PowerofAttorney) |
| 107\* | [Calculation of Filing Fee Table.](pmn-20250813xexfees.htm) |

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\*Filed herewith

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Item 9. <u>Undertakings</u>.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a)The undersigned Registrant hereby undertakes:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(1)To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(i) To include any prospectus required by Section 10(a)(3) of the Securities Act;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the SEC pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than 20% change in the maximum aggregate offering price set forth in the "Calculation of Registration Fee" table in the effective registration statement; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

*Provided, however,* that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the registration statement is on Form S-8 and the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the SEC by the Registrant pursuant to Section 13 or Section 15(d) of the Exchange Act that are incorporated by reference in the registration statement.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(2)That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(3)To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)The undersigned Registrant hereby undertakes that, for purposes of determining any liability under the Securities Act, each filing of the Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan's annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(h)Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director, officer or controlling person of the Registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

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#### SIGNATURES
Pursuant to the requirements of the Securities Act, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Toronto, Ontario, Canada on August 13, 2025.

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| | | |
|:---|:---|:---|
| **PROMIS NEUROSCIENCES INC.** | **PROMIS NEUROSCIENCES INC.** | **PROMIS NEUROSCIENCES INC.** |
| By: | /s/ Neil Warma | /s/ Neil Warma |
|  | Name: | Neil Warma |
|  | Title: | Chief Executive Officer |

---

Each person whose signature appears below constitutes and appoints Neil Warma, Daniel E. Geffken, and Max A. Milbury, or any of them, as his or her true and lawful attorneys-in-fact and agents, each of whom may act alone, with full powers of substitution and resubstitution, for him or her and in his name, place and stead, in any and all capacities, to sign any or all amendments to this registration statement, including post-effective amendments to this registration statement, registration statements filed pursuant to Rule 429 under the Securities Act, and any related registration statements necessary to register additional securities, and to file the same, with all exhibits thereto, and other documents and in connection therewith, with the Commission, granting unto said attorneys-in-fact and agents, and each of them the full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully to all intents and purposes as he or she might or could do in person, and hereby ratifies and confirms all his or her said attorneys-in-fact and agents or any of them or his or her substitute or substitutes may lawfully do or cause to be done by virtue hereof.

This Power of Attorney may be executed in multiple counterparts, each of which shall be deemed an original, but which taken together shall constitute one instrument.

Pursuant to the requirements of the Securities Act, this registration statement has been signed by the following persons in the capacities indicated on August 13, 2025.

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| | |
|:---|:---|
| **Signature** | **Title** |
| /s/ Neil Warma | Chief Executive Officer and Director |
| Neil Warma | (Principal Executive Officer) |
| /s/ Daniel E. Geffken | Chief Financial Officer |
| Daniel E. Geffken | (Principal Financial Officer) |
| /s/ Max A. Milbury | Vice President, Finance |
| Max A. Milbury | (Principal Accounting Officer) |
| /s/ Neil Cashman | Chief Science Officer and Director |
| Neil Cashman |  |
| /s/ Maggie Shafmaster | Lead Independent Director |
| Maggie Shafmaster |  |
| /s/ William Wyman | Director |
| William Wyman |  |
| /s/ Patrick Kirwin | Director |
| Patrick Kirwin |  |
| /s/ Josh Mandel-Brehm | Director |
| Josh Mandel-Brehm |  |
| /s/ Eugene Williams | Director |
| Eugene Williams |  |

---

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#### AUTHORIZED REPRESENTATIVE
Pursuant to the requirements of Section 6(a) of the Securities Act of 1933, as amended, the undersigned has signed this Form S-8, solely in its capacity as duly authorized representative of ProMIS Neurosciences Inc. in the United States, on August 13, 2025.

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| | |
|:---|:---|
|  | **PROMIS NEUROSCIENCES INC.** |
| By: | /s/ Neil Warma |
| Name: | Neil Warma |
| Title: | Authorized Representative in the United States |

---

------

## Exhibit 5.1

**Exhibit 5.1**

![Graphic](pmn-20250813xex5d1002.jpg)<br>

Our File No.: 58123V-319414

August 13, 2025

ProMIS Neurosciences Inc. <br>Suite 200, 1920 Yonge Street

Toronto, Ontario

M4S 3E2

<u>Attention: Board of Directors</u>

**Re:** **ProMIS Neurosciences Inc. (the "Corporation") -** <br> **Stock Option Plan** 

We have acted as Canadian counsel for the Corporation in connection with the preparation and filing of a registration statement on Form S-8 (the "**Registration Statement**") with the Securities and Exchange Commission (the "**Commission**") pursuant to the United States *Securities Act of 1933*, as amended (the "**Act**"). The Registration Statement relates to the registration of 5,083,128 common shares in the capital of the Corporation (the "**Shares**") reserved for issuance with respect to: (i) the exercise of stock options (each, a "**2015 Stock Option**") granted pursuant to and in accordance with the Corporation's stock option plan as amended as of June 29, 2015 and as reapproved by shareholders of the Corporation on June 30, 2021 (the "**2015 Stock Option Plan**"); and (ii) the exercise of stock options (each, a "**2025 Stock Option**" and together with the 2015 Stock Options, the "**Stock Options**") granted or future awards of 2025 Stock Options granted pursuant to the Corporation's 2025 stock option and incentive plan as approved by the board of directors on April 28, 2025 and approved by shareholders on June 12, 2025 (the "**2025 Stock Option Plan**" and together with the 2015 Stock Option Plan, the "**Stock Option Plans**").

In rendering the opinion set forth below, we have reviewed:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) the Registration Statement and the exhibits thereto;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) the Articles and Bylaws of the Corporation in effect as of the date hereof;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c) certain records of the Corporation's corporate proceedings as reflected in its minute book, including resolutions of the board of directors of the Corporation (the "**Board**") approving the Stock Option Plans and various Stock Options granted pursuant to the Stock Option Plans;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d) an officer's certificate (the "**Officer's Certificate**") signed by the Corporation's Chief Executive Officer; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(e) such other documents as we have deemed relevant.

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| |
|:---|
| &nbsp;&nbsp;&nbsp; \| Patent & Trademark Agents \| Avocats \| Agents de brevets et de marques de commerce<br> \| Calgary \| Toronto \| Ottawa \| Montréal \| mcmillan.ca<br>|
| &nbsp;&nbsp;&nbsp;McMillan LLP \| Brookfield Place, 181 Bay Street, Suite 4400, Toronto, Ontario, Canada M5J 2T3 \| t 416.865.7000 \| f 416.865.7048<br>Lawyers \| Patent & Trademark Agents \| Avocats \| Agents de brevets et de marques de commerce<br>Vancouver \| Calgary \| Toronto \| Ottawa \| Montréal \| mcmillan.ca |

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|:---|:---|
|  | <br>2<br>|
| ![Graphic](pmn-20250813xex5d1002.jpg) | <br>August 13, 2025<br>Page 2 |

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Subject to the foregoing and the assumptions, limitations and qualifications set forth in this letter, it is our opinion the Shares will be validly issued and fully paid and non-assessable Shares in the capital of the Corporation when issued pursuant to the exercise of Stock Options granted pursuant to the Stock Option Plans, provided that:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) such Stock Options are granted in accordance with the terms and conditions of the applicable Stock Option Plan; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) the persons receiving any Stock Options under the Stock Option Plans perform their obligations to the Corporation in accordance with the terms and conditions of the applicable Stock Option Plan and any agreement evidencing the grant of the Stock Options, including the payment of the required exercise price with respect to Stock Options.

Our opinion expressed herein is subject in all respects to the following assumptions, limitations and qualifications:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) The foregoing opinion is limited to the laws of the Province of Ontario, including all applicable provisions of the *Business Corporations Act* (Ontario) (the "**OBCA** "). We have not considered, and have not expressed any opinion with regard to, or as to the effect of, any other law, rule or regulation, state or federal, applicable to the Corporation. In particular, we express no opinion as to United States federal securities laws.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) We have assumed: (i) the genuineness of all signatures on documents examined by us; (ii) the legal capacity of the officers of the Corporation; (iii) the authenticity of all documents submitted to us as originals; (iv) the conformity to authentic originals of all documents submitted to us as certified, conformed, photostatic or other copies; and (v) that the documents, in the forms submitted to us for our review, have not been and will not be altered or amended in any respect.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c) We have assumed that: (i) each Stock Option granted or to be granted pursuant to a Stock Option Plan has been or will be duly authorized by the Board in accordance with the Articles and Bylaws of the Corporation, the OBCA and the applicable Stock Option Plan; and (ii) each agreement governing a Stock Option granted under a Stock Option Plan has been or will be duly executed by each party thereto and constitutes or will constitute the legal, valid and binding obligations of the parties thereto, and that such agreements are or will be enforceable against each of the parties thereto in accordance with their respective terms.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d) We have assumed that each of the statements made and certified in the Officer's Certificate was true and correct when made, has at no time since being made and certified become untrue or incorrect and remains true and correct on the date hereof.

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|:---|:---|
|  | <br>3<br>|
| ![Graphic](pmn-20250813xex5d1002.jpg) | <br>August 13, 2025<br>Page 3 |

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&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(e) We are solicitors qualified to practice law in the Province of Ontario. The opinions expressed herein are limited to the laws of Ontario and the federal laws of Canada applicable therein, in each case as in effect on the date hereof. We express no opinion as to the laws of any other jurisdiction. We wish to advise you that we have no responsibility and assume no responsibility to advise you of any changes to applicable laws or any changes involving the Corporation after the date hereof.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(f) We have assumed that at the time the Corporation is or becomes obligated to issue any Shares upon exercise of Stock Options granted pursuant to the Stock Option Plans, the Corporation: (i) will have adequate authorized and unissued Shares to fulfill such obligations; and (ii) will be in good standing under the OBCA.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(g) We have assumed the absence of fraud in any transaction pursuant to which Shares have been or may be issued pursuant to the exercise of any Stock Option under the Stock Option Plans and that the consideration authorized by the Board for the Shares will have been received by the Corporation prior to their issuance.

We consent to the use of this opinion as an exhibit to the Registration Statement and further consent to the use of our name wherever appearing in the Registration Statement, including the Prospectus constituting a part thereof, and in any amendment thereto.

Yours truly,

"*McMillan LLP*"

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## Exhibit 23.1

**Exhibit 23.1**

**CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM**

We hereby consent to the incorporation by reference in this Registration Statement on Form S-8 of our report dated March 31, 2025 relating to the consolidated financial statements of ProMIS Neurosciences Inc., which appears in the Company's Annual Report on Form 10-K for the year ended December 31, 2024. Our report includes an explanatory paragraph relating to the Company's ability to continue as a going concern.

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| |
|:---|
| /s/ BAKER TILLY US, LLP |
| Tewksbury, Massachusetts |
| August 13, 2025 |

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## Ex-Filing

?xml version='1.0' encoding='ASCII'? EX-FILING FEES

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| |
|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Calculation of Filing Fee Tables**  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **S-8**  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **ProMIS Neurosciences Inc.**  |

---

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Security Type**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Security Class Title**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Fee Calculation Rule**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Amount Registered**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Proposed Maximum Offering Price Per Unit**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Maximum Aggregate Offering Price**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Fee Rate**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Amount of Registration Fee**  |
| 1 | Equity | 2015 Stock Plan Common Shares, no par value per share | Other | 2136409 | $0.57 | $1217753.13 | 0.0001531 | $186.44 |
| 2 | Equity | 2025 Stock Option and Incentive Plan Common Shares, no par value per share | Other | 2946719 | $0.57 | $1679629.83 | 0.0001531 | $257.15 |
| Total Offering Amounts: | Total Offering Amounts: | Total Offering Amounts: | Total Offering Amounts: | Total Offering Amounts: |  | $2897382.96  |  | $443.59  |
| Total Fee Offsets:  | Total Fee Offsets:  | Total Fee Offsets:  | Total Fee Offsets:  | Total Fee Offsets:  |  |  |  | $0.00  |
| Net Fee Due:  | Net Fee Due:  | Net Fee Due:  | Net Fee Due:  | Net Fee Due:  |  |  |  | $443.59  |

---

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Offering Note** <br>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <sup>1</sup> Note 1.a. In accordance with Rule 416(a) under the Securities Act of 1933, as amended (the "Securities Act"), this registration statement shall be deemed to cover any additional securities that may from time to time be offered or issued to prevent dilution resulting from stock splits, stock dividends or similar transactions effected without the receipt of consideration which results in an increase in the number of our outstanding common shares, no par value per share ("Common Shares"). Note 1.b. Estimated solely for the purpose of calculating the registration fee pursuant to Rules 457(c) and 457(h) of the Securities Act. The price per share and aggregate offering price are calculated on the basis of $0.57, the average of the high and low price of the registrant's Common Shares as reported on the Nasdaq Capital Market on August 8, 2025. Note 1.c. Consists of 2,136,409 Common Shares previously reserved for issuance under the Registrant's 2015 Stock Option Plan, as amended (the "2015 Plan"). Shares available for issuance under the 2015 Plan were previously registered on a registration statement on Form S-8 filed with the Securities and Exchange Commission on September 7, 2022 (File No. 333-267319).

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <sup>2</sup> See Offering Note 1.a. and 1.b. Consists of 2,946,719 Common Shares newly reserved for issuance under the Registrant's 2025 Stock Option and Incentive Plan.

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| | |
|:---|:---|
| | |
| **Rule 457(p)** | **Rule 457(p)** |
| Fee Offset Claims | N/A |
| Fee Offset Sources | N/A |

---