The FDA approved leucovorin for treatment of cerebral folate deficiency (CFD) after reviewing published literature and real‑world evidence; the decision follows public attention when then‑FDA Commissioner Marty Makary had highlighted leucovorin’s purported promise for autism. The lead sentence: regulators granted an indication for a decades‑old generic based on aggregated clinical reports and observational data rather than new randomized trials. The approval formalizes an established off‑label practice for a rare metabolic condition and exemplifies the agency’s use of real‑world evidence for niche indications.