The FDA has initiated approval of leucovorin calcium tablets (Wellcovorin) for the treatment of cerebral folate deficiency (CFD), an ultra-rare neurological disorder that affects folate transport in the brain.[3][1] CFD is associated with developmental delays with autistic manifestations such as problems with social communication, sensory processing, repetitive behaviors, seizures, and movement and coordination disorders.[3][1] The agency conducted a systematic review of the literature from 2009 to 2024, including case reports with patient-level data and mechanistic data supporting the benefit of leucovorin in CFD.[3][2] Wellcovorin was withdrawn from the market in 1999 at the request of GSK, which manufactured it, and now the FDA is working with GSK to expand the label for adult and pediatric patients.[1][5] Leukovorin is not a cure for autism spectrum disorders and may only improve speech deficits in a subset of children.[1][2] The FDA emphasized the limitations of available data and the need for further studies to assess safety and efficacy.[2]