An Open-Label Extension Study of Palovarotene Treatment in Fibrodysplasia Ossificans Progressiva (FOP)
brief summary
Fibrodysplasia Ossificans Progressiva (FOP) is a rare, severely disabling disease characterized by heterotopic ossification (HO), i.e., abnormal bone formation, often associated with painful, recurrent episodes of soft tissue swelling (flare-ups). Lesions begin in early childhood and lead to progressive ankyloses of major joints with resultant loss of movement. In this study, the ability of different palovarotene dosing regimens to prevent the formation of new HO will be evaluated in adult and pediatric participants with FOP.
detailed description
The main objective of this Phase 2, multicenter, open-label study is to evaluate the safety and efficacy of different palovarotene dosing regimens in participants with FOP. Efficacy will be assessed based on the ability of palovarotene to prevent the formation of new heterotopic ossification (HO) as assessed by low-dose whole body computed tomography (WBCT) scan, excluding head.
The study was divided into four parts: Part A (completed on July 2017), Part B (completed on October 2018), Part C (completed) and Part D (completed). Each part was associated with revised palovarotene treatment regimens.
In Part A, all pediatric and adult participants who successfully completed Study PVO-1A-201 were enrolled and followed for up to 36 months. Participants who had an eligible flare-up received 10 mg palovarotene daily for 14 days, followed by 5 mg palovarotene daily for 28 days (or weight-based equivalent).
In Part B, participants who successfully completed Study PVO-1A-201 (including any participant who participated in Part A of Study PVO-1A-202) as well as up to 20 new adult participants were followed for up to 24 months. The Adult Cohort included all participants with at least 90% skeletal maturity, regardless of age. The Pediatric Cohort included all participants with less than 90% skeletal maturity. Any Pediatric Cohort participant who achieved ≥90% skeletal maturity during Part B was considered for enrollment into the Adult Cohort at the discretion of the Investigator. Part B added a 5 mg palovarotene daily chronic treatment regimen administered between flare-ups for participants in the Adult Cohort for up to 24 months. Part B also increased the flare-up dosing to 20 mg palovarotene daily for 28 days, followed by 10 mg palovarotene daily for 56 days (or weight-adjusted equivalents in the Pediatric Cohort). Treatment could be extended if the flare-up was still ongoing.
In Part C, participants from Part B are being followed for up to an additional 48 months. There will be no new participants in Part C. All eligible participants, including skeletally immature participants, are receiving 5 mg palovarotene daily chronic treatment regimen (weight-adjusted doses for skeletally immature participants).
In Part D, annual post last dose of study treatment assessments for up to 2 years will be obtained in participants who were skeletally immature at the time of study treatment discontinuation in order to obtain longer-term safety data. No new participants will be enrolled into Part D.
Part C plus Part D duration will not exceed 48 months.
official title
A Phase 2, Open-Label Extension, Efficacy and Safety Study of a Retinoic Acid Receptor Gamma (RARγ) Specific Agonist (Palovarotene) in the Treatment of Preosseous Flare-ups in Subjects With Fibrodysplasia Ossificans Progressiva (FOP)