In-Home Evaluation of Episodic Administration of Palovarotene in Fibrodysplasia Ossificans Progressiva (FOP) Subjects

Fibrodysplasia Ossificans Progressiva (FOP) is a rare, severely disabling disease characterized by painful, recurrent episodes of soft tissue swelling (flare-ups) that result in abnormal bone formation (heterotopic ossification or HO) in muscles, tendons, and ligaments. Flare-ups begin early in life and may occur spontaneously or after soft tissue trauma, vaccinations, or influenza infections. Recurrent flare-ups progressively restrict movement by locking joints leading to cumulative loss of function and disability. Mouse models of FOP have demonstrated the ability of retinoic acid receptor gamma (RARγ) agonists such as palovarotene to prevent HO following injury. This 36-month study will evaluate the long-term safety and efficacy of episodic treatment with palovarotene for flare-ups in FOP subjects who successfully complete two flare-up treatment periods (6 weeks duration) and two follow-up periods (6 weeks duration) in Study PVO-1A-202.