[Form 4] Larimar Therapeutics, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Larimar Therapeutics reported that an entity associated with Deerfield Management received a grant of stock options linked to 55,150 shares of common stock. The options have an exercise price of $3.33 per share and expire on May 19, 2036.

The option was granted to Jonathan S. Leff, who serves on Larimar’s board, but is held for the benefit and at the direction of Deerfield Management Company, L.P. It is scheduled to vest on the earlier of May 19, 2027 or the date of Larimar’s next annual stockholder meeting, subject to Leff’s continued board service. The reporting persons disclaim beneficial ownership beyond any indirect pecuniary interest.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Flynn James E, DEERFIELD MANAGEMENT COMPANY, L.P.

Role null | null

Type	Security	Shares	Price	Value
Grant/Award	Stock Option (Right to Buy)	55,150	$0.00	--

Holdings After Transaction: Stock Option (Right to Buy) — 55,150 shares (Indirect, Through Deerfield Management Company, L.P.)

Footnotes (1)

1. Jonathan S. Leff, a partner in Deerfield Management Company, L.P., serves as a director of the Issuer. The option granted to Jonathan S. Leff and reported herein is held for the benefit, and at the direction, of Deerfield Management Company, L.P. ("Deerfield Management"). The option was granted on May 19, 2026 and is scheduled to vest on the earlier of May 19, 2027 and the date of the Issuer's next annual meeting of stockholders, in each case, subject to Jonathan S. Leff 's continued service on the board of directors of the Issuer. This Form 4 is being filed by the undersigned as well as the entity listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). James E. Flynn is the sole member of the general partner of Deerfield Management Company, L.P. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

Form 4 Insider Transactions: What Each Field Means →

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

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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^*

Flynn James E

(Last) (First) (Middle)

345 PARK AVENUE SOUTH, 12TH FLOOR

(Street)

NEW YORK NEW YORK 10010

(City) (State) (Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/19/2026

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

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

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

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

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
Stock Option (Right to Buy)	$3.33	05/19/2026		A		55,150(1)		(2)	05/19/2036	Common Stock	55,150(1)	$0	55,150(1)	I	Through Deerfield Management Company, L.P.(1)(3)

1. Name and Address of Reporting Person^*

Flynn James E

(Last) (First) (Middle)

345 PARK AVENUE SOUTH, 12TH FLOOR

(Street)

NEW YORK NEW YORK 10010

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

DEERFIELD MANAGEMENT COMPANY, L.P.

(Last) (First) (Middle)

345 PARK AVENUE SOUTH, 12TH FLOOR

(Street)

NEW YORK NEW YORK 10010

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

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

Explanation of Responses:

1. Jonathan S. Leff, a partner in Deerfield Management Company, L.P., serves as a director of the Issuer. The option granted to Jonathan S. Leff and reported herein is held for the benefit, and at the direction, of Deerfield Management Company, L.P. ("Deerfield Management").

2. The option was granted on May 19, 2026 and is scheduled to vest on the earlier of May 19, 2027 and the date of the Issuer's next annual meeting of stockholders, in each case, subject to Jonathan S. Leff 's continued service on the board of directors of the Issuer.

3. This Form 4 is being filed by the undersigned as well as the entity listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). James E. Flynn is the sole member of the general partner of Deerfield Management Company, L.P. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

Remarks:

Jonathan S. Leff, a partner in Deerfield Management, serves as a director of the Issuer. Jonathan Isler, Attorney-in-Fact: Power of Attorney, which is hereby incorporated by reference to Exhibit 24 to a Form 3 with regard to BiomX Inc. filed with the Securities and Exchange Commission on March 19, 2024 by Deerfield Private Design Fund V, L.P., Deerfield Healthcare Innovations Fund II, L.P., Deerfield Mgmt V, L.P., Deerfield Mgmt HIF II, L.P., Deerfield Management Company, L.P. and James E. Flynn.

	/s/ Jonathan Isler, Attorney-in-Fact	05/20/2026
	** 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

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

Larimar reported a grant of stock options covering 55,150 common shares. The options were granted to director Jonathan S. Leff for the benefit of Deerfield Management Company, L.P., reflecting equity-based compensation rather than an open-market share purchase or sale.

What are the key terms of the Larimar (LRMR) stock options granted to the Deerfield-affiliated entity?

The options cover 55,150 shares of Larimar common stock at an exercise price of $3.33 per share. They expire on May 19, 2036, providing long-dated equity exposure tied to Larimar’s share price performance over the next decade.

When do the Larimar (LRMR) options granted to the Deerfield-related director vest?

The option vests on the earlier of May 19, 2027 or the date of Larimar’s next annual stockholder meeting. Vesting is contingent on Jonathan S. Leff continuing to serve on Larimar’s board of directors through that vesting date milestone.

Who is considered to benefit from the Larimar (LRMR) option grant reported in this Form 4?

The option is held for the benefit and at the direction of Deerfield Management Company, L.P. The reporting persons, including James E. Flynn and Deerfield Management, disclaim beneficial ownership except for any indirect pecuniary interest they may have in the securities.

Is the Larimar (LRMR) Form 4 transaction an insider purchase or sale of common stock?

No, the Form 4 reports a grant of stock options, not an open-market stock purchase or sale. It is classified as a derivative grant or award acquisition, providing rights to buy common shares at a fixed $3.33 exercise price in the future.

How many Larimar (LRMR) options does the Deerfield-affiliated reporting person hold after this transaction?

Following this grant, the filing shows 55,150 stock options related to Larimar common stock held indirectly through Deerfield Management Company, L.P. These options represent the full amount reported as beneficially owned after the transaction.