Gene therapies (2015-2025): determinants of translational success

Over the past decade, 28 gene therapies have received regulatory approvals in the United States, yet a larger number of pipeline candidates failed. Comprehensive evaluation of gene therapies from both ends of the translational spectrum requires a unified framework through which all therapies can be efficiently analyzed and compared. Here, we present a pharmacological and operational framework consisting of five determinants of translational success. Three upstream pharmacological determinants-vector design and delivery systems, target biology and disease context, and immunological/toxicological barriers-determine efficacy, durability, and safety and collectively shape the major clinical outcomes. Two downstream operational determinants-manufacturing scalability and sustainable payment models-ultimately govern real-world implementation and commercial viability. Using this unified framework, we analyzed the 28 gene therapies approved between 2015 and 2025 alongside 8 discontinued, delayed, or withdrawn programs. Our results reveal a hierarchical model of translational success, where upstream pharmacological determinants govern regulatory approval, whereas downstream operational determinants dictate market success. Less successful programs failed when one or more determinants were compromised, demonstrating that regulatory approval and commercial viability are distinct translational milestones. Beyond analyzing retrospective data, applying this framework allows us to project key gene therapy advancements over the next decade. Ultimately, this five-determinant model serves as a strategic blueprint to streamline pipeline development and accelerate the delivery of next-generation gene therapies.