FDA Approves First Therapy for Rare Cerebral Folate Deficiency

The U.S. Food and Drug Administration has approved an expanded indication for Wellcovorin to treat patients with cerebral folate deficiency linked to variants in the Folate Receptor 1 (FOLR1) gene, marking the first approved therapy for this rare genetic neurological disorder.

The approval allows the drug, also known as Leucovorin Calcium, to be used in both adult and pediatric patients diagnosed with cerebral folate deficiency caused by FOLR1 gene variants (CFD-FOLR1). The decision highlights growing regulatory efforts to accelerate treatments for rare diseases that currently lack approved therapeutic options.

Cerebral folate deficiency is a rare neurological disorder that disrupts the transport of folate, an essential vitamin for brain development and function, into the brain. Without sufficient folate levels in the central nervous system, patients may experience a range of severe symptoms including developmental delays, movement abnormalities, seizures, and other neurological complications. The condition often appears early in childhood and can significantly affect long-term neurological development.

According to FDA officials, the approval was supported by a comprehensive review of published medical literature, including case reports with patient-level clinical data and mechanistic studies explaining how leucovorin improves folate availability in the brain. Because the condition is extremely rare, traditional large-scale clinical trials are difficult to conduct, making carefully documented real-world evidence an important part of the regulatory evaluation.

“Today’s approval represents a significant milestone for patients living with cerebral folate transport deficiency due to the FOLR1 variant, a rare genetic condition that has had no FDA-approved treatment options until now,” said Marty Makary, commissioner of the FDA. He noted that the treatment could help individuals with developmental delays associated with autistic features caused by impaired folate transport.

The agency worked with GlaxoSmithKline, the holder of the drug’s New Drug Application, to update the prescribing information for Wellcovorin. The revised labeling now includes guidance on using the drug for patients diagnosed with CFD-FOLR1, ensuring physicians have the necessary safety and efficacy information.

Tracy Beth Hoeg said the approval also demonstrates how regulatory pathways can adapt to support therapies for ultra-rare conditions. She emphasized that observational and real-world evidence can play a crucial role when it clearly shows clinical benefit compared with the natural progression of a disease.

Like other medications, leucovorin may cause side effects. Reported reactions include itching, rash, hives, breathing difficulties, chills accompanied by shivering, and disruptions in body temperature regulation. In rare cases, patients may experience anaphylaxis, a severe allergic reaction requiring immediate medical attention.

The FDA said the approval represents an important step in addressing unmet medical needs among patients with rare genetic disorders. By enabling the use of leucovorin for CFD-FOLR1, the agency hopes to provide clinicians and families with a treatment option that could improve neurological outcomes and quality of life for affected individuals.