Document

S-8 1 acumenpharma-sx82026.htm S-8 Document

As filed with the Securities and Exchange Commission on March 26, 2026

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

Acumen Pharmaceuticals, Inc.

(Exact name of registrant as specified in its charter)


Delaware			36-4108129
(State or other jurisdiction of incorporation or organization)			(I.R.S. Employer Identification No.)

1210-1220 Washington St., Suite 210

Newton, MA 02465

(617) 344-4190

(Address of principal executive offices, including zip code)

Acumen Pharmaceuticals, Inc. 2021 Equity Incentive Plan

Acumen Pharmaceuticals, Inc. 2021 Employee Stock Purchase Plan

(Full titles of the plans)

Daniel O’Connell

Chief Executive Officer

Acumen Pharmaceuticals, Inc.

1210-1220 Washington St., Suite 210

Newton, MA 02465

(617) 344-4190

(Name, address and telephone number, including area code, of agent for service)

Copies to:


Thomas J. Danielski, Esq.			Derek Meisner
Ropes & Gray LLP			Chief Legal Officer
800 Boylston Street			Acumen Pharmaceuticals, Inc.
Boston, MA 02199			1210-1220 Washington St., Suite 210
(617) 951-7000			Newton, MA 02465
			(617) 344-4190

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 Exchange Act.


Large accelerated filer	☐	Accelerated filer	☐

Non-accelerated filer	☒	Smaller reporting company	☒

		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. ☐

EXPLANATORY NOTE

REGISTRATION OF ADDITIONAL SHARES

Acumen Pharmaceuticals, Inc. (the “Registrant”) is filing this Registration Statement on Form S-8 with the Securities and Exchange Commission (the “Commission”) for the purpose of registering (i) 3,028,768 additional shares of its common stock under the 2021 Equity Incentive Plan (the “2021 Plan”), pursuant to the provisions of the 2021 Plan providing for an automatic increase in the number of shares of common stock reserved and available for issuance under the 2021 Plan on January 1, 2026, (ii) 29,069 additional shares of its common stock under the 2021 Plan pursuant to the provisions of the 2021 Plan providing that shares subject to outstanding stock options or other stock awards that were granted under the Registrant’s 2013 Amended and Restated Stock Performance Plan (the “Prior Plan”) that terminate or expire prior to exercise or settlement, are settled in cash, are forfeited or repurchased because of the failure to vest, or are reacquired or withheld to satisfy a tax withholding obligation or the purchase or exercise price in accordance with the terms of the Prior Plan become available for issuance under the 2021 Plan, and (iii) 605,754 additional shares of its common stock under the 2021 Employee Stock Purchase Plan (the “2021 ESPP,” and together with the 2021 Plan the “Plans”), pursuant to the provisions of the 2021 ESPP providing for an automatic increase in the number of shares of common stock reserved and available for issuance under the 2021 ESPP on January 1, 2026. Pursuant to General Instruction E to Form S-8, the Registrant incorporates by reference, except to the extent supplemented, amended or superseded by the information set forth herein, into this Registration Statement the entire contents of its Registration Statements on Form S-8 (File No. 333-257666) filed with the Commission on July 2, 2021, Form S-8 (File No. 333-263947) filed with the Commission on March 29, 2022, Form S-8 (File No. 333-270902) filed with the Commission on March 28, 2023, Form S-8 (File No. 333-278267) filed with the Commission on March 27, 2024 and Form S-8 (File No. 333-286176) filed with the Commission on March 27, 2025.

PART II

INFORMATION REQUIRED IN REGISTRATION STATEMENT

ITEM 8. EXHIBITS

Incorporated by Reference

Exhibit

Number

Description

Schedule
Form

File Number

Exhibit

Filing Date

3.1

Amended and Restated Certificate of Incorporation of the Registrant.

8-K

001-40551

3.1

June 8, 2023

3.2

Amended and Restated Bylaws of the Registrant.

8-K

001-40551

3.1

March 15, 2023

5.1*

Opinion of Ropes & Gray LLP.

23.1*

Consent of Ropes & Gray LLP (included in Exhibit 5.1).

23.2*

Consent of Ernst & Young, LLP, independent registered public accounting firm.

24.1*

Power of Attorney (included on the signature page of this Form S-8).

99.1

2021 Equity Incentive Plan and Forms of Option Grant Notice and Agreement, Exercise Notice, Early Exercise Notice and Restricted Stock Award Notice.

S-1/A

333-256945

10.2

June 24, 2021

99.2

2021 Employee Stock Purchase Plan

S-1/A

333-256945

10.4

June 24, 2021

107*

Filing Fee Table

__________________

*Filed herewith.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, 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 the City of Newton, Commonwealth of Massachusetts, on March 26, 2026.


ACUMEN PHARMACEUTICALS, INC.

By:			/s/ Daniel O’Connell
			Daniel O’Connell
			Chief Executive Officer

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Daniel O’Connell, William Matthew Zuga and Derek Meisner, and each one of them, as his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and in their name, place or stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this registration statement, and to file the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that 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.

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.

Signature

Title

Date

/s/ Daniel O’Connell

Chief Executive Officer and Director

March 26, 2026

Daniel O’Connell

(Principal Executive Officer)

/s/ William Matthew Zuga

Chief Financial Officer and Chief Business Officer

March 26, 2026

William Matthew Zuga

(Principal Financial and Accounting Officer)

/s/ Kimberlee C. Drapkin

Director

March 26, 2026

Kimberlee C. Drapkin

/s/ Nathan B. Fountain

Director

March 26, 2026

Nathan B. Fountain, M.D.

/s/ George Golumbeski

Director

March 26, 2026

George Golumbeski, Ph.D.

/s/ Jeffrey L. Ives

Director

March 26, 2026

Jeffrey L. Ives, PhD

/s/ Derrell D. Porter

Director

March 26, 2026

Derrell D. Porter, M.D.

/s/ Sean Stalfort

Director

March 26, 2026

Sean Stalfort

/s/ Laura Stoppel

Director

March 26, 2026

Laura Stoppel, PhD

SEC Form S-8 filed by Acumen Pharmaceuticals Inc.