X0306 4 2022-01-06 0 0001658551 Amylyx Pharmaceuticals, Inc. AMLX 0001235598 FRATES JAMES M C/O AMYLYX PHARMACEUTICALS, INC. 43 THORNDIKE STREET CAMBRIDGE MA 02142 0 1 0 0 Chief Financial Officer Common Stock 2022-01-06 4 A 0 31667 0.00 A 31667 D Stock Option (right to buy) 19.00 2022-01-06 4 A 0 142500 0.00 A 2032-01-06 Common Stock 142500 142500 D The reported transaction involves the Reporting Person's receipt of a restricted stock unit award (a "RSU"). The RSU shall vest in 4 equal annual installments, with the first installment vesting on the first anniversary of the date of the grant, subject to the Reporting Person's continued service to the Issuer through such vesting date. 1/4 of the shares subject to the option shall vest and become exercisable on the one year anniversary of the date of grant, and the remaining shares shall vest monthly over the remaining 36 months, subject to the Reporting Person's continuous service to the Issuer through such vesting date. /s/ Joshua B. Cohen, as Attorney in Fact for James Frates 2022-01-10