Justin B. Klee - 05 Mar 2026 Form 4 Insider Report for Amylyx Pharmaceuticals, Inc. (AMLX)

Role: Co-Chief Executive Officer, Director
Signature: /s/ Joshua B. Cohen, as Attorney in Fact
Issuer symbol: AMLX
Transactions as of: 05 Mar 2026
Net transactions value: $0
Form type: 4
Filing time: 09 Mar 2026, 16:00:05 UTC
Previous filing: 04 Mar 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Klee Justin B.	Co-Chief Executive Officer, Director	C/O AMYLYX PHARMACEUTICALS, INC., 55 CAMBRIDGE PARKWAY, SUITE 6W, CAMBRIDGE	/s/ Joshua B. Cohen, as Attorney in Fact	09 Mar 2026	0001898314

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	AMLX	Common Stock	Award		+248,865	+7.5%	$0.000000^*	3,583,481	05 Mar 2026	Direct	F1

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	AMLX	Stock Option (Right to Buy)	Award		+373,295		$0.000000^*	373,295	05 Mar 2026	Common Stock	373,295	$14.10	Direct	F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The reported transaction involves the Reporting Person's receipt of a restricted stock unit ("RSU") award. The RSUs shall vest in 4 equal annual installments, with the first installment vesting on March 1, 2027, subject to the Reporting Person's continued service to the Issuer through each such vesting date.
F2	25% of the shares subject to the option shall vest and become exercisable on March 1, 2027, and the remaining shares shall vest monthly over the remaining 36 months, subject to the Reporting Person's continuous service to the Issuer through each such vesting date.