SC 13G/A

Names of Reporting Persons

James B. Murray, Jr.

Check the Appropriate Box if a Member of a Group (see instructions)

(a) ☐ (b) ☐

SEC USE ONLY

Citizenship or Place of Organization

United States of America

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)*

Acumen Pharmaceuticals, Inc.

(Name of Issuer)

Common Stock, $0.0001 par value per share

(Title of Class of Securities)

00509G209

(CUSIP Number)

December 31, 2023

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

☐

Rule 13d-1(b)

☒

Rule 13d-1(c)

☐

Rule 13d-1(d)

*	The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 00509G209

Item 1(a).

Name of Issuer: Acumen Pharmaceuticals, Inc. (the “Issuer”)

Item 1(b).

Address of Issuer’s Principal Executive Offices: 427 Park Street, Charlottesville, VA 22092

Item 2(a).

Name of Person Filing:

James B. Murray, Jr.

Item 2(b).

Address of Principal Business Office or, if none, Residence: The address and principal business office of the Reporting Person is:

c/o Murray Enterprises, LLC

427 Park Street

Charlottesville, VA 22902

Item 2(c).

Citizenship:

United States of America

Item 2(d).

Title of Class of Securities:

Common Stock, $0.0001 par value per share

Item 2(e).

CUSIP Number:

00509G209

Item 3.

If this statement is filed pursuant to §§240.13d-1(b), or 240.13d-2(b) or (c), check whether the person filing is a:


(a)	☐	Broker or dealer registered under Section 15 of the Act (15 U.S.C. 78o);

(b)	☐	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);

(c)	☐	Insurance company as defined in section 3(a)19) of the Act (15 U.S.C. 78c);

(d)	☐	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);

(e)	☐	An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E);

(f)	☐	An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F);

(g)	☐	A parent holding company or control person in accordance with §240.13d-1(b)(1)(ii)(G);

(h)	☐	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i)	☐	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j)	☐	A non-U.S. institution in accordance with §240.13d–1(b)(1)(ii)(J);

(k)	☐	Group, in accordance with §240.13d–1(b)(1)(ii)(K).

	If filing as a non-U.S. institution in accordance with §240.13d–1(b)(1)(ii)(J), please specify the type of institution:

Item 4.

Ownership

Provide the following information regarding the aggregate number and percentage of the class of securities of the Issuer identified in Item 1.

(a)

Amount Beneficially Owned:

As of December 31, 2023, Mr. Murray beneficially owned 2,681,057 shares of the Issuer’s Common Stock, consisting of: (i) 2,538,162 shares held by James B. Murray, Jr., as Trustee of the James B. Murray, Jr. Revocable Trust U/A/D 8/5/1991 and (ii) 142,895 shares held by Praxis Technologies L.P. James B. Murray, Jr. is the General Partner of Praxis Technologies, L.P. and has the power to vote or dispose of shares held by the entity. The holders of Common Stock are entitled to one vote per share.

(b)

Percent of Class:

Percent of Common Stock and total voting power of the Issuer’s Common Stock is based on the denominator of 57,910,461 shares of the Issuer’s Common Stock outstanding as of November 9, 2023, as disclosed in the Issuer’s Form 10-Q filed with the Securities and Exchange Commission on November 13, 2023.

Based on the above, Mr. Murray beneficially owned 4.6% of the Issuer’s outstanding Common Stock, representing 4.6% of the total voting power of the Issuer’s outstanding Common Stock.

(c)

Number of shares as to which the person has:

(i)

Sole power to vote or to direct the vote: 2,681,057

(ii)

Shared power to vote or to direct the vote: 0

(iii)

Sole power to dispose or to direct the disposition of: 2,681,057

(iv)

Shared power to dispose or to direct the disposition of: 0

Item 5.

Ownership of 5 Percent or Less of a Class

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than 5 percent of the class of securities, check the following ☒.

Item 6.

Ownership of More than 5 Percent on Behalf of Another Person

Not applicable.

Item 7.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person.

Not applicable.

Item 8.

Identification and Classification of Members of the Group

Not applicable.

Item 9.

Notice of Dissolution of a Group

Not applicable.

Item 10.

Certification

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the Issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

January 24, 2024

Date

/s/ James B. Murray, Jr.

James B. Murray, Jr.