Jonathan S. Leff - 19 May 2026 Form 4 Insider Report for Larimar Therapeutics, Inc. (LRMR)

Reporting relationship: Director
Issuer ticker: LRMR
Reported as of: 19 May 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 20 May 2026, 18:03:57 UTC
Prior SEC filing: 14 May 2025
Source filing: View source filing
Reporting owner signature: /s/ Jennifer Johansson, Attorney-in-fact

Key filing fact

Jonathan S. Leff filed Form 4 for Larimar Therapeutics, Inc. (LRMR) on 20 May 2026.

Key facts

This page summarizes Jonathan S. Leff's Form 4 filing for Larimar Therapeutics, Inc. (LRMR).
1 reported transaction and 1 derivative row are listed below.
Accepted by SEC: 20 May 2026, 18:03.

Change

Previous filing in this sequence was filed on 14 May 2025.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001215242 Primary reporting owner

LEFF JONATHAN S

Relationship: Director
Address: C/O LARIMAR THERAPEUTICS, INC., THREE BALA PLAZA EAST, SUITE 506, BALA CYNWYD
Signature: /s/ Jennifer Johansson, Attorney-in-fact
Signature date: 20 May 2026

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

LRMR transaction Derivative

Stock Option (Right to Buy)

Award

Transaction value
Shares: +55,150
Change %
Price: $0.000000^*
Shares after: 55,150
Date: 19 May 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 55,150
Exercise price: $3.33
Footnotes: F1, F2

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote F1

The Reporting Person, a partner in Deerfield Management Company, L.P., has no pecuniary interest in the securities reported herein and disclaims beneficial ownership of such securities. The Reporting Person holds the options for the benefit, and at the direction, of Deerfield Management Company, L.P.

Footnote F2

The options vest on the earlier of (a) May 19, 2027 or (b) the date of the Company's next annual meeting of stockholders, in each case subject to the Reporting Person's continued service on the Board of Directors of the Company.