The FDA unveiled guidance aimed at enabling a more modular approval approach for gene therapies—framed as a ‘plug and play’ framework—designed to accelerate personalized treatments across patient subgroups. The agency’s plan builds on its recent moves to speed development and review of therapies tailored to different subsets of a disease. The guidance is intended to provide a clearer approval pathway for treatments that can be swapped or reused across different patient populations, potentially reducing development cycle times for component updates. For developers, it raises practical questions about how regulators will evaluate interchangeability, comparability, and manufacturing changes. In the gene-therapy pipeline, the regulatory signal is that modularity may become an explicit strategy for scaling innovation while maintaining evidence expectations for safety and efficacy across defined patient groups.