FDA approves Pasatru for adults with FOP

The US Food and Drug Administration (FDA) has approved Pasatru (garetosmab) for adults living with fibrodysplasia ossificans progressiva (FOP). FOP is an extremely rare genetic disorder where skeletal muscle and connective tissues gradually ossify, turning into bone and severely restricting movement.

The approval is based on results from the phase 3 OPTIMA clinical trial involving 63 adults. At 56 weeks, both the 10 mg/kg and 3 mg/kg doses of garetosmab significantly reduced the formation of new heterotopic ossification (HO) lesions compared to a placebo, showing reductions of 90% and 94% respectively as measured by CT scans. The treatment also reduced clinician-assessed flare-ups.

Garetosmab is a monoclonal antibody that works by blocking Activin A, a protein critical to the development of new bone lesions in FOP patients. This marks the second FDA-approved treatment for the condition, following the 2023 approval of Sohonos.