The FDA approved GSK's Wellcovorin (leucovorin calcium) as the first treatment for cerebral folate transport deficiency (CFD-FOLR1) in adult and pediatric patients with a confirmed FOLR1 gene variant.134
Approval was based on a systematic review of published literature, case reports, and mechanistic data, not new clinical trial data, due to the ultra-rare nature of the condition (20-50 documented cases worldwide).123
The approval is narrower than initially promoted; it does not extend to broader autism treatment despite prior White House discussions, as insufficient data was found for that indication.12
FDA Commissioner Marty Makary called it a significant milestone for patients with no prior approved options, potentially benefiting those with developmental delays and autistic features.3
This reflects FDA's flexibility in using real-world evidence for ultra-rare diseases while maintaining evidentiary standards, per Acting CDER Director Tracy Beth Hoeg.13
Sources:
1. https://www.pharmexec.com/view/fda-approves-leucovorin-without-clinical-trial-cerebral-folate-transport-deficiency-report
2. https://www.statnews.com/2026/03/11/biotech-news-fda-approves-leucovorin-for-rare-disorder/
3. https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-patients-cerebral-folate-transport-deficiency
4. https://www.fiercepharma.com/pharma/fda-approves-leucovorin-ultra-rare-cerebral-folate-deficiency-subset-without-clinical-trial