Amylyx Pharmaceuticals Inc

During the three months ended December 31, 2023, the following officers or directors of the Company (as defined in Rule 16a-1(f)) adopted the following trading plans for the sale of our common stock pursuant to the terms of the applicable plan; such plans are intended to satisfy the affirmative defense conditions of Rule 10b5–1(c)(1) of the Exchange Act:

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Joshua Cohen, our Co-Chief Executive Officer and a member of our board of directors, adopted a new Rule 10b5-1 trading plan on December 15, 2023, which is scheduled to expire on November 30, 2024. The aggregate number of shares of our common stock authorized to be sold under this new arrangement is 60,000;

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Justin Klee, our Co-Chief Executive Officer and a member of our board of directors, adopted a new Rule 10b5-1 trading plan on December 15, 2023, which is scheduled to expire on November 30, 2024. The aggregate number of shares of our common stock authorized to be sold under this new arrangement is 60,000.

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James Frates, our Chief Financial Officer, adopted a new Rule 10b5-1 trading plan on December 14, 2023, which is scheduled to expire on December 1, 2024. The aggregate number of shares of our common stock authorized to be sold under this new arrangement is 90,000.

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Gina M. Mazzariello, our Chief Legal Officer and General Counsel, adopted a new Rule 10b5-1 trading plan on December 14, 2023, which is scheduled to expire on March 8, 2025. The aggregate number of shares of our common stock authorized to be sold under this new arrangement is 76,290, which includes shares that may be withheld or sold to cover withholding taxes at the time of vesting.

Noother director or officer hasadopted orterminated any non-Rule 10b5-1 trading arrangements during the quarter ended December 31, 2023.