REGN FDA decision: Aug 19, 2026

Garetosmab was approved by the FDA on August 19, 2026 for fibrodysplasia Ossificans Progressiva (FOP).

Pasatru (garetosmab-grts) approved on August 19, 2026 - twelve days before its August 31 PDUFA goal date - as the first treatment for fibrodysplasia ossificans progressiva.

Run-up into the decision (T-120 → T+5)

Key facts

The PDUFA target action date was August 31, 2026; the FDA approved the BLA on August 19, twelve days early, under Priority Review. Pasatru is a fully human monoclonal antibody blocking Activin A, and the first and only FDA-approved treatment shown in a placebo-controlled trial to reduce both new heterotopic ossification lesions and clinician-assessed flare-ups in adults with FOP, an ultra-rare genetic disorder affecting roughly 900 diagnosed people worldwide. Approval rests on the Phase 3 OPTIMA trial: a 90% reduction in new HO lesions at 56 weeks at the 10 mg/kg dose (94% at 3 mg/kg) versus placebo by CT scan, with an 88% reduction in clinician-assessed flare-ups at the higher dose. Garetosmab previously held Fast Track and Orphan Drug designations. An EMA submission is under review.

Run-up figures are the stock's own daily closing path over the 120 trading days before the decision, from our price history. Cohort move is the historical median absolute decision-day move for this market-cap tier. History, not a prediction.

Primary source: Regeneron press release, August 19, 2026

FDA record of the action: the FDA approved on August 19, 2026, per BLA 761508 ORIG-1 (FDA letter). The sponsor announced it the same day. Action dates on pdufa.bio come from the FDA's own record, not the press release. Every FDA action we hold, by FDA date: FDA approval letters.