Amylyx (AMLX) Co-CEO awarded 373,295 options and 248,865 RSUs

Rhea-AI Filing Summary

Amylyx Pharmaceuticals Co-Chief Executive Officer Justin B. Klee reported equity awards from the company. He received a stock option for 373,295 shares at an exercise price of $0.0000 per share and a grant of 248,865 shares of common stock as restricted stock units (RSUs).

The RSUs vest in four equal annual installments starting on March 1, 2027, conditioned on his continued service. The option vests 25% on March 1, 2027, with the remaining shares vesting monthly over the next 36 months, also subject to continued service. After these grants, he reported owning 3,583,481 shares of common stock directly.

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

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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^*

Klee Justin B.

(Last) (First) (Middle)

C/O AMYLYX PHARMACEUTICALS, INC.

55 CAMBRIDGE PARKWAY, SUITE 6W

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Amylyx Pharmaceuticals, Inc. [ AMLX ]

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

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Co-Chief Executive Officer

3. Date of Earliest Transaction (Month/Day/Year)
03/05/2026

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	03/05/2026		A		248,865(1)	A	$0	3,583,481	D

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)	$14.1	03/05/2026		A		373,295		(2)	03/05/2036	Common Stock	373,295	$0	373,295	D

Explanation of Responses:

1. 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.

2. 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.

	/s/ Joshua B. Cohen, as Attorney in Fact	03/09/2026
	** 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 did Amylyx (AMLX) Co-CEO Justin B. Klee report in this Form 4 filing?

The filing reports Justin B. Klee’s receipt of new equity awards from Amylyx. He was granted a stock option for 373,295 shares and 248,865 restricted stock units, both awarded at no cash cost, as part of his compensation and subject to future vesting conditions.

How many stock options and RSUs did Justin B. Klee receive from Amylyx (AMLX)?

Justin B. Klee received a stock option covering 373,295 shares and an award of 248,865 restricted stock units. These equity grants increase his potential future ownership, subject to vesting schedules and continued service requirements with Amylyx Pharmaceuticals, as detailed in the Form 4 footnotes.

What are the vesting terms for Justin B. Klee’s RSUs and stock options at Amylyx (AMLX)?

The RSUs vest in four equal annual installments beginning on March 1, 2027, contingent on continued service. For the stock option, 25% of the shares vest on March 1, 2027, with the remaining shares vesting monthly over the following 36 months, also requiring continuous service.

How many Amylyx (AMLX) common shares does Justin B. Klee report owning after these awards?

After the reported equity awards, Justin B. Klee reports direct ownership of 3,583,481 shares of Amylyx common stock. This figure reflects his position following the grant of 248,865 restricted stock units and the stock option covering 373,295 shares disclosed in the Form 4.