Amylyx Pharmaceuticals, Inc.

Pursuant to the Polypeptide Term Sheet, the Company and Polypeptide shall negotiate in good faith and promptly enter into a definitive written agreement consistent with the terms set forth in the Polypeptide Term Sheet and other mutually agreeable terms and conditions (the “Polypeptide Manufacturing Agreement”). Under the Term Sheet, the Company will pay a $30 million upfront fee to Polypeptide for capacity reservation and in consideration of the commitments described therein.

Pursuant to the Polypeptide Term Sheet, and subject to the execution of the Polypeptide Manufacturing Agreement, the Company and Polypeptide have agreed, among other things: (i) that beginning in 2028, the Company will purchase a minimum quantity of avexitide drug substance per calendar year during the term of the Polypeptide Manufacturing Agreement at the applicable supply price; (ii) that the Company will provide periodic estimates of its supply needs to Polypeptide, a portion of which will be binding upon both parties, and (iii) to fixed volume-based pricing, as may be adjusted on an annual basis.

The foregoing descriptions of the Bachem Manufacturing Agreement and Polypeptide Term Sheet are qualified in their entirety by reference to the full text of the Bachem Manufacturing Agreement and Polypeptide Term Sheet, respectively, copies of which will be filed as exhibits to the Company’s Quarterly Report on Form 10-Q for the fiscal quarter ending September 30, 2026.