Director adds 100,000 Larimar (LRMR) shares in underwritten stock offering

Rhea-AI Filing Summary

Larimar Therapeutics, Inc. director Thomas Edward Hamilton bought 100,000 shares of common stock in an underwritten offering at $5.00 per share, which closed on February 27, 2026. Following this open-market purchase, he directly owns 664,798 shares and indirectly holds 159,433 shares through Post Edison, LLC.

SEC Form 4

FORM 4

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
or Section 30(h) of the Investment Company Act of 1940

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

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Hamilton Thomas Edward

(Last) (First) (Middle)

C/O LARIMAR THERAPEUTICS, INC.

THREE BALA PLAZA EAST, SUITE 506

(Street)

BALA CYNWYD PA 19004

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Larimar Therapeutics, Inc. [ LRMR ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
02/27/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	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
Common Stock	02/27/2026		P		100,000(1)	A	$5	664,798	D
Common Stock								159,433	I	Post Edison, LLC

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 (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	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 (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (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: 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

Explanation of Responses:

1. Represents shares of common stock purchased in the underwritten offering of Larimar Therapeutics, Inc. at the offering price, which closed on February 27, 2026.

	/s/ Jennifer Johansson, Attorney-in-fact	03/02/2026
	** Signature of Reporting Person	Date
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).
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FAQ

What insider transaction did Larimar Therapeutics (LRMR) report on this Form 4?

Larimar Therapeutics reported that director Thomas Edward Hamilton bought 100,000 common shares at $5.00 each. The purchase took place in an underwritten offering that closed on February 27, 2026, and increased his directly held position in the company.

How many Larimar Therapeutics (LRMR) shares does the director own after the transaction?

After the transaction, Thomas Edward Hamilton directly owns 664,798 Larimar Therapeutics common shares. He also indirectly holds 159,433 additional shares through Post Edison, LLC, reflecting both direct and indirect economic exposure to the company’s stock following the offering.

At what price did the Larimar Therapeutics (LRMR) director buy new shares?

Thomas Edward Hamilton purchased the new Larimar Therapeutics shares at $5.00 per share. The filing notes these 100,000 common shares were acquired in the company’s underwritten offering at the offering price, which closed on February 27, 2026.

Was the Larimar Therapeutics (LRMR) insider purchase part of an offering?

Yes, the director’s 100,000-share purchase was made in Larimar Therapeutics’ underwritten offering. The Form 4 footnote specifies the shares were bought at the offering price in a deal that closed on February 27, 2026, rather than in ordinary market trading.

Does the Larimar Therapeutics (LRMR) Form 4 show indirect share ownership?

Yes, the Form 4 shows Thomas Edward Hamilton has indirect ownership of 159,433 common shares through Post Edison, LLC. This is in addition to his directly held 664,798 shares, indicating both personal and entity-based holdings associated with the director.