Co-Manager on Dyne Therapeutics' Follow-On Offering

Dyne Therapeutics, Inc. (“Dyne”) (Nasdaq: DYN), a biotechnology company focused on advancing innovative life-transforming therapeutics for people living with genetically driven muscle diseases, announced on Thursday the pricing of its underwritten public offering of 17,150,000 shares of its common stock at a price of $17.50 per share. Gross proceeds, before deducting underwriting discounts and commissions and estimated offering expenses, were approximately $300.1 million. Dyne granted the underwriters a 30-day option to purchase up to 2,572,500 additional shares of common stock at the public offering price, less underwriting discounts and commissions; the underwriters have exercised this option in full, resulting in a total offering size of $345.1 million.

Dyne recently announced positive initial clinical data from the ACHIEVE clinical trial of DYNE-101 in patients with myotonic dystrophy type 1 (DM1) and the DELIVER clinical trial of DYNE-251 in patients with Duchenne muscular dystrophy (DMD) who have mutations amenable to exon 51 skipping. The Company’s platform, FORCE, is focused on developing modern oligonucleotide therapeutics to overcome limitations in delivery to muscle tissue. The Company’s pipeline also includes DYN-301, a preclinical program for facioscapulohumeral muscular dystrophy (FSHD).