The FDA unveiled draft guidance aimed at expanding access to personalized gene therapies for rare diseases, proposing a “plug and play” approval model. Under the plan, a developer could secure approval for a therapy targeting one mutation using a traditional clinical approach, then later seek authorizations for other mutations using laboratory data rather than new full-scale trials. The agency will define an “individualized feature space” within the original application, laying out how subsequent mutation-specific claims could be supported. The FDA also connected the draft to its broader rare disease framework initiative, including standards focused on individual conditions. Prime Medicine and Beam Therapeutics were cited as companies where the framework could have near-term relevance for base-editing programs targeting multiple rare variants.