WilmerHale represented the underwriters in the public offering of 17,500,000 shares of common stock by Amylyx Pharmaceuticals, Inc., a clinical-stage pharmaceutical company with a mission to develop novel therapies for communities with high unmet needs, including people living with serious and fatal neurodegenerative diseases and endocrine conditions. In connection with the public offering, Amylyx granted the underwriters a 30-day option to purchase up to an additional 2,625,000 shares of common stock at the public offering price, less the underwriting discounts and commissions. Amylyx received approximately $201.3 million in gross proceeds, excluding underwriting discounts and commissions and other offering-related expenses, reflecting the full exercise of the underwriters’ option to purchase additional shares. The offering priced on September 9, 2025, and closed on September 11, 2025.

The WilmerHale team representing the underwriters included Lisa Firenze, Liz Graffeo and Tim Kolankowski with assistance from Barish Ozdamar on intellectual property matters.