Sec Form 3 Filing - Klee Justin B. @ Amylyx Pharmaceuticals, Inc. - 2022-01-06

FORM 3 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

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, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Klee Justin B. 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 (Last) (First) (Middle) C/O AMYLYX PHARMACEUTICALS, INC., 43 THORNDIKE STREET 3. Date of Earliest Transaction (MM/DD/YY) 01/06/2022 (Street) CAMBRIDGE, MA02142 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 2,484,195 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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 7. Title and Amount of Underlying Securities (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 of Derivative Security: 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) $ 0.37 ( 1 ) 02/16/2023 Common Stock 334,520 D Stock Option (Right to Buy) $ 1.57 ( 2 ) 02/26/2025 Common Stock 100,000 D Stock Option (Right to Buy) $ 7.57 ( 3 ) 02/19/2026 Common Stock 200,000 D Series C-1 Preferred Stock ( 4 ) ( 4 ) ( 4 ) Common Stock 4,870 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Klee Justin B. C/O AMYLYX PHARMACEUTICALS, INC. 43 THORNDIKE STREET CAMBRIDGE, MA02142 X Co-Chief Executive Officer Signatures /s/ Justin Klee 01/06/2022 Signature of Reporting Person Date

Explanation of Responses:

( 1 )6,977 shares subject to such stock option vested and became exercisable on March 16, 2018 and the remainder of the shares vest in monthly installments of 6,969 shares for a period of 47 months after the vesting commencement date. ( 2 )25,012 shares subject to such option vested and became exercisable on February 26, 2021 and the remainder of the shares vest in monthly installments of 2,083 shares thereafter. ( 3 )50,024 shares subject to such option shall vest and become exercisable on February 19, 2022 and the remainder of the shares vest in monthly installments of 4,166 shares thereafter. ( 4 )Each share of Series C-1 preferred stock is convertible on a one-for-one basis into Common Stock at any time at the election of the Reporting Person and will automatically convert upon the closing of the Issuer's initial public offering into the number of shares of the Issuer's Common Stock shown in column 3 without payment or further consideration. The Series C-1 Preferred stock has no expiration 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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