Affinia Therapeutics Closes $40 Million Series C to Advance AAV Gene Therapy for Heart Failure

WALTHAM, MA – Affinia Therapeutics, an innovative AAV gene therapy company, today announced it has closed a $40 million Series C financing round. The funding was led by New Enterprise Associates (NEA), with strategic participation from new investor Eli Lilly & Company, alongside existing backers including Atlas Venture, F-Prime, and GV (formerly Google Ventures).

The proceeds are specifically earmarked to accelerate the development of Affinia’s lead program, AFTX-201, a potential first-in-class and best-in-class investigational AAV genetic medicine designed to treat BAG3 dilated cardiomyopathy (DCM), a severe inherited heart condition.

Pivotal Trial Set to Begin in Early 2026

The capital infusion will fund the final stages of IND-enabling studies for AFTX-201. Affinia expects to submit an Investigational New Drug (IND) application to the U.S. Food and Drug Administration (FDA) in the fourth quarter of 2025.

If the IND is accepted, the company plans to initiate the UPBEAT trial, a Phase 1/2 clinical trial for patients with BAG3 DCM, in the first quarter of 2026.

Ed Mathers, General Partner at NEA and Affinia Board Member, expressed confidence in the company: “We are pleased to be joined by this world-class syndicate of investors who share our enthusiasm about Affinia’s science and robust pipeline to treat devastating cardiovascular and neurological diseases.”

Novel AAV Capsids and AI Platform

AFTX-201 leverages Affinia’s proprietary technology, which includes a generative AI discovery platform used to engineer novel myotropic AAV capsids—the delivery vehicles for the AAV gene therapy—that target the heart and skeletal muscles while achieving liver detargeting.

AFTX-201 is designed to deliver a fully human, full-length BAG3 transgene using Affinia’s novel cardiotropic AAV capsid engineered for efficient and selective cardiac transduction at low doses. AFTX-201 is intended to be given as a simple one-time intravenous administration. Preclinical studies in an animal disease model demonstrated that AFTX-201 improved BAG3 protein levels in the heart and completely restored cardiac function, whereas such benefits were not achieved with the same gene construct using a conventional AAV capsid at the same dose.

BAG3 DCM affects over 70,000 patients across the U.S., Europe, and the U.K. Almost 25% of patients currently require a heart transplant despite standard care.

“This financing recognizes the potential of our novel AAV 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, Affinia’s Chief Executive Officer.