Affinia Therapeutics Secures $40 Million to Advance First-in-Class Gene Therapy for Rare Heart Disease

Affinia Therapeutics has announced the close of a $40 million Series C financing round to advance development of its lead gene therapy candidate, AFTX-201, for the treatment of BAG3 dilated cardiomyopathy (DCM)—a rare, inherited heart condition with high mortality and limited treatment options.

The round was led by New Enterprise Associates (NEA) and included new investor Eli Lilly & Company, along with continued support from existing backers such as Alexandria Venture Investments, Atlas Venture, GV (formerly Google Ventures), Avidity Partners, F-Prime, Mass General Brigham Ventures, and Perceptive Advisors.

Affinia plans to use the funding to complete IND-enabling studies for AFTX-201, with an Investigational New Drug (IND) application submission expected in the fourth quarter of 2025. Pending regulatory approval, the company will launch its Phase 1/2 clinical trial—dubbed the UPBEAT trial—in early 2026 to evaluate the therapy in patients with BAG3 DCM.

AFTX-201 is designed as a one-time intravenous gene therapy to deliver a fully human, full-length BAG3 transgene using Affinia’s proprietary cardiotropic capsid. The novel capsid technology, developed using Affinia’s generative AI discovery platform, is engineered for efficient and selective targeting of heart tissue while minimizing liver exposure. In preclinical studies, AFTX-201 showed a complete restoration of cardiac function in animal models—an outcome not achieved using conventional capsids at the same dose.

“This financing recognizes the potential of our novel capsids and the value of our lead program AFTX-201, bringing it one step closer to potentially become the first-in-class and best-in-class genetic medicine to treat BAG3 DCM,” said Rick Modi, CEO of Affinia Therapeutics.

BAG3 DCM is caused by mutations in the BAG3 gene, which leads to insufficient levels of the BAG3 protein that is essential for maintaining the structure and function of heart cells. The condition affects more than 70,000 patients across the U.S., Europe, and the U.K., and often progresses to heart failure at an early age. Despite available treatments, nearly a quarter of patients eventually require heart transplantation.

Ed Mathers, General Partner at NEA and Affinia board member, noted the strong backing from investors reflects confidence in the company’s science and therapeutic pipeline.

Affinia says it will also use the funding to continue development of its broader gene therapy portfolio targeting other serious cardiovascular and neurological diseases.