Accelerated Approval As The New "Norm" In Gene Therapy For Rare Diseases

By Keith Wonnacott, Charu Sojan, Tara Hun-Dorris, Katie Bates, Seema Shetty, Lexeo Therapeutics, Inc.

Gene therapy has revolutionized treatment prospects for rare genetic disorders by enabling corrective or replacement strategies at the molecular level. Since its first FDA approvals, more than 30 cell and gene therapies have reached the market, with 30–50 additional approvals anticipated by 2030. The FDA has increasingly leveraged its Accelerated Approval pathway to expedite gene therapy access based on surrogate endpoints. This shift has sparked debate over drug pricing, confirmatory trial delays, and evidentiary standards, prompting the 2023 Consolidated Appropriations Act to strengthen FDA authority and mandate clearer post-approval requirements.

In response, the FDA issued two draft guidances (December 2024 and January 2025) clarifying accelerated approval processes and confirmatory‐trial expectations. While the European Medicines Agency’s (EMA’s) conditional marketing authorizations remain more conservative, the FDA’s commitment to regulatory flexibility is poised to expand gene therapy development, offering patients earlier access to transformative treatments worldwide.