The FDA unveiled draft guidance aimed at making personalized gene therapies easier to approve for rare diseases, proposing a pathway where companies can add additional mutation targets later using lab data rather than repeat full clinical studies. The draft focuses on therapies designed to correct different mutations within the same gene. Under the proposal, a sponsor could first obtain approval for one personalized therapy using a more traditional evidence package, then seek clearance for additional mutations through what the FDA calls an “individualized feature space” defined in the initial application. The FDA framed the change as an access and feasibility effort, citing that clinical trials for each ultra-rare mutation can be impractical or unprofitable. The move also connects to the agency’s Rare Disease Framework Initiative, which seeks standards at the level of individual conditions rather than a one-size-fits-all model. Company reaction was immediate in the draft’s early window: Prime Medicine was flagged as potentially relevant by analysts, and Beam Therapeutics’ shares moved higher after CEO John Evans commented that the concept aligns with base-editing science.