Dyne Therapeutics Inc. has entered into a First Amendment to its existing Loan and Security Agreement with Hercules Capital, Inc. and other lenders, allowing the company to borrow a second term loan tranche of $50 million as of December 8, 2025. The amended agreement also provides Dyne with access to two additional term loan tranches totaling up to $75 million, contingent on meeting specified clinical, regulatory, and commercial milestones. An additional final tranche of up to $50 million may be available, subject to lender approval. The loan bears interest at the Wall Street Journal prime rate plus 2.45%, with a floor of 7.50%, and matures on July 1, 2030. Dyne may make interest-only payments until July 1, 2028, with the possibility of extending this period upon achievement of certain milestones. The company has granted a first-priority security interest in substantially all of its assets as collateral for the loan.