Amylyx Pharmaceuticals Inc

(c)

During thethree months ended September 30, 2024, no officers or directors of the Company (as defined in Rule 16a-1(f))adopted orterminated a “Rule 10b5-1 trading arrangement” or a “non-Rule 10b5-1 trading arrangement,” as each term is defined in Item 408(a) of Regulation S-K of the Exchange Act, except as described below:

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James Frates, our Chief Financial Officer, terminated a Rule 10b5-1 trading plan on September 10, 2024, which was scheduled to expire on December 1, 2024. The Rule 10b5-1 trading plan, which wasadopted on December 14, 2023 to satisfy the affirmative defense conditions of Rule 10b5-1(c), provided for the sale of up to 90,000 shares of our common stock.

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George Milne, a member of ourboard of directors, terminated a Rule 10b5-1 trading plan on September 16, 2024, which was scheduled to expire on December 1, 2024. The Rule 10b5-1 trading plan, which wasadopted on September 15, 2023 to satisfy the affirmative defense conditions of Rule 10b5-1(c), provided for the sale of up to 106,000 shares of our common stock.

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Gina M. Mazzariello, our Chief Legal Officer and General Counsel, terminateda Rule 10b5-1 trading plan on September 19, 2024, which was scheduled to expire on March 8, 2025. The Rule 10b5-1 trading plan, which wasadopted on December 14, 2023 to satisfy the affirmative defense conditions of Rule 10b5-1(c), provided for the sale of up to 76,290 shares of our common stock.