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

Rhea-AI Filing Summary

Form 4 filed 8 Aug 2025 shows that Deerfield-affiliated funds led by managing partner James E. Flynn increased their ownership in Larimar Therapeutics (LRMR).

• Date of trade: 31 Jul 2025
• Type: Open-market purchases (Code “P”)
• Shares bought: 9,375,000 common shares in aggregate:
• Deerfield Private Design Fund III: 3,387,529 sh @ $3.20
• Deerfield Private Design Fund IV: 3,387,539 sh @ $3.20
• Deerfield Healthcare Innovations Fund: 2,599,932 sh @ $3.20
• Cash outlay: ≈ $30.0 million
• Post-trade holdings (indirect): Fund III 9.54 m, Fund IV 9.54 m, HIF 7.32 m, Deerfield Partners 4.21 m shares
• Flynn, Deerfield Mgmt entities and the funds remain directors by deputization and >10 % beneficial owners.

The filing consolidates positions across multiple Deerfield vehicles; each filer disclaims beneficial ownership beyond its economic interest. No derivative transactions were reported.

Positive

• Large insider purchase: 9.4 m shares (~$30 m) acquired on the open market indicates confidence from a sophisticated healthcare investor.
• Stake reinforcement: Deerfield funds now hold well above the 10 % threshold, aligning their interests with minority shareholders.

Negative

• None.

Insights

Portfolio Manager

TL;DR – ~$30 m insider buy by 10 % holder is a bullish sentiment signal.

These sizeable open-market purchases lift Deerfield’s combined stake past 30 m shares, reaffirming its strategic commitment. Buying at $3.20—near recent lows—suggests confidence in Larimar’s risk-reward ahead of clinical milestones. Although Form 4s do not guarantee future performance, funds rarely deploy this scale without conviction. Investors often view such cluster buying by a sophisticated healthcare specialist as a positive catalyst for near-term price support.

Corporate Governance Expert

TL;DR – Concentrated control increases but remains properly disclosed.

Deerfield’s aggregate purchases strengthen its influence, yet the group continues to file jointly, mitigating transparency concerns. With a partner sitting on the board, governance watchpoints include potential related-party dynamics, but current disclosure complies with Section 16. No red flags on insider selling or undisclosed derivatives were noted.

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
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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 NY 10010

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

3. Date of Earliest Transaction (Month/Day/Year)
07/31/2025

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

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

	Form filed by One Reporting Person
X	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	07/31/2025		P		3,387,529	A	$3.2	9,538,918	I	Through Deerfield Private Design Fund III, L.P.(1)(2)
Common Stock	07/31/2025		P		3,387,539	A	$3.2	9,538,945	I	Through Deerfield Private Design Fund IV, L.P.(1)(2)
Common Stock	07/31/2025		P		2,599,932	A	$3.2	7,321,129	I	Through Deerfield Healthcare Innovations Fund, L.P.(1)(2)
Common Stock								4,207,982	I	Through Deerfield Partners, L.P.(1)(2)

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

1. Name and Address of Reporting Person^*

Flynn James E

(Last) (First) (Middle)

345 PARK AVENUE SOUTH, 12TH FLOOR

(Street)

NEW YORK NY 10010

(City) (State) (Zip)

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 NY 10010

(City) (State) (Zip)

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 Mgmt III, L.P.

(Last) (First) (Middle)

345 PARK AVENUE SOUTH, 12TH FLOOR

(Street)

NEW YORK NY 10010

(City) (State) (Zip)

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 Mgmt HIF, L.P.

(Last) (First) (Middle)

345 PARK AVENUE SOUTH, 12TH FLOOR

(Street)

NEW YORK NY 10010

(City) (State) (Zip)

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 Mgmt IV, L.P.

(Last) (First) (Middle)

345 PARK AVENUE SOUTH, 12TH FLOOR

(Street)

NEW YORK NY 10010

(City) (State) (Zip)

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 Mgmt L.P.

(Last) (First) (Middle)

345 PARK AVENUE SOUTH, 12TH FLOOR

(Street)

NEW YORK NY 10010

(City) (State) (Zip)

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 Private Design Fund III, L.P.

(Last) (First) (Middle)

345 PARK AVENUE SOUTH, 12TH FLOOR

(Street)

NEW YORK NY 10010

(City) (State) (Zip)

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 Healthcare Innovations Fund, L.P.

(Last) (First) (Middle)

345 PARK AVENUE SOUTH, 12TH FLOOR

(Street)

NEW YORK NY 10010

(City) (State) (Zip)

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 Private Design Fund IV, L.P.

(Last) (First) (Middle)

345 PARK AVENUE SOUTH, 12TH FLOOR

(Street)

NEW YORK NY 10010

(City) (State) (Zip)

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 PARTNERS, L.P.

(Last) (First) (Middle)

345 PARK AVENUE SOUTH, 12TH FLOOR

(Street)

NEW YORK NY 10010

(City) (State) (Zip)

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. This Form 4 is being filed by the undersigned as well as the entities listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). Deerfield Mgmt III, L.P. is the general partner of Deerfield Private Design Fund III, L.P. ("Fund III"). Deerfield Mgmt IV, L.P. is the general partner of Deerfield Private Design Fund IV, L.P. ("Fund IV"). Deerfield Mgmt HIF, L.P. is the general partner of Deerfield Healthcare Innovations Fund, L.P. ("Deerfield HIF"). Deerfield Mgmt, L.P. is the general partner of Deerfield Partners, L.P. ("Deerfield Partners"). Deerfield Management Company, L.P. is the investment manager of Deerfield Partners, L.P., Fund III, Fund IV and Deerfield HIF (collectively, the "Funds"). James E. Flynn is the sole manager of the general partner of each of Deerfield Mgmt III, L.P., Deerfield Mgmt IV, L.P., Deerfield Mgmt HIF, L.P., Deerfield Mgmt, L.P. and Deerfield Management Company, L.P.

2. In accordance with Instruction 4 (b)(iv) to Form 4, the entire amount of the Issuer's securities held by the Funds is reported herein. 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	08/04/2025
	** 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.

FAQ

How many LRMR shares did Deerfield buy on 31 July 2025?

The funds purchased 9,375,000 common shares at $3.20 each.

What was the total dollar amount of the insider purchase?

Approximate cash outlay was $30.0 million.

What is Deerfield’s ownership in Larimar Therapeutics after the transaction?

Indirect holdings total over 30 million shares across multiple funds, maintaining >10 % ownership.

Did the filing disclose any derivative positions?

No derivative securities were reported in Table II of the Form 4.

Who signed the Form 4 for Deerfield?

Attorney-in-Fact Jonathan Isler signed on behalf of James E. Flynn and associated entities.