The FDA said it is looking for additional outside input as it reassesses criteria used for rare disease drug development, including how much efficacy and safety evidence is sufficient to support approvals. The agency framed the effort around endpoint selection and the practical challenges of studying small, diverse patient populations. The move comes as more rare-disease therapies reach the agency’s review queues, increasing pressure to standardize how endpoints are justified when natural history data can be limited. Industry stakeholders have increasingly debated how regulators should calibrate confidence when patient numbers constrain traditional trial designs. By inviting external perspectives, FDA is signaling that rare disease guidance and review expectations may evolve, potentially affecting how sponsors structure endpoints, statistical plans, and evidence packages going forward.