144 0001179552 XXXXXXXX LIVE 0001658551 Amylyx Pharmaceuticals, Inc. 001-41199 55 Cambridge Parkway, CAMBRIDGE MA 02142 (617)-682-0917 GEORGE MILNE Director Common Morgan Stanley Smith Barney LLC Executive Financial Services

1 New York Plaza 8th Floor New York NY 10004

100000 2779000.00 111423048 10/05/2026 NASDAQ Common 08/08/2016 Private Acquisition from Issuer or an Affiliate Issuer N 86757 08/08/2016 N/A Common 12/11/2019 Previously Exercised Options Issuer N 13243 12/11/2019 Cash Y 10/05/2026 04/28/2026 /s/ Dr. George Milne