Dyne Therapeutics, Inc. (Nasdaq: DYN) has closed an upsized underwritten public offering of 21,045,000 shares of common stock at $20.50 per share, according to a company statement.

The offering generated gross proceeds of approximately $431.4 million before underwriting discounts, commissions, and other expenses. The total share count includes 2,745,000 shares issued after underwriters exercised their option to purchase additional shares in full. All shares were sold by Dyne.

Morgan Stanley, Jefferies, Evercore ISI, LifeSci Capital, and Raymond James served as joint book-running managers. Jones acted as lead manager.

The offering was conducted under a shelf registration statement filed with the Securities and Exchange Commission on March 5, 2024, which became automatically effective upon filing.

Dyne Therapeutics is a clinical-stage company developing therapeutics for genetically driven neuromuscular diseases, with active clinical programs targeting Duchenne muscular dystrophy and myotonic dystrophy type 1.