An Efficacy and Safety Study of Palovarotene to Treat Preosseous Flare-ups in FOP Subjects

Phase 2CompletedNCT02190747

Clementia Pharmaceuticals Inc.40 enrolled

Overview

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 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 (RAR) gamma agonists to prevent heterotopic ossification (HO) following injury. The purpose of the study is to evaluate whether palovarotene, an RAR gamma agonist, will prevent HO during and following a flare-up in subjects with FOP.

The primary objective is to evaluate the ability of different doses of palovarotene to prevent HO at the flare-up site in subjects with FOP as assessed by plain radiographs. This is a Phase 2, multi-center, randomized, double-blind, sponsor-unblinded, placebo-controlled study. Two cohorts of subjects will be randomized into different dosing regimens of palovarotene for a 6-week (42 days) treatment period. The study will consist of three periods: 1. A Screening period to occur within 7 days of a distinct flare-up. The first dose of study drug will be taken within 7 days of the flare-up initiation. 2. A double-blind treatment period of 6 weeks (42 days) duration. 3. A follow-up period of 6 weeks (42 days) duration. An initial cohort (Cohort 1) of subjects will be randomly assigned 3:1 to either palovarotene or placebo daily for 42 days. Subjects randomized to palovarotene in Cohort 1 will receive an initial daily dose of 10 mg for 14 days followed by 5 mg daily for 28 days. In Cohort 2, new FOP subjects meeting all inclusion/exclusion criteria will be randomly assigned 3:3:2 to two dose regimens of palovarotene (10 mg for 14 days and 5 mg for 28 days; 5 mg for 14 days and 2.5 mg for 28 days) or placebo daily for 42 days. Doses will be weight-adjusted and subjects randomized within three weight-range categories (20 to \<40 kg, 40 to \<60 kg, and ≥60 kg). Subjects completing the study and still meeting eligibility requirements will be given the opportunity to enroll into an open-label extension study.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Eligibility

Sex: ALLMin age: 6 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Written, signed, and dated informed subject/parent consent or age-appropriate assent. * Subjects clinically diagnosed with classic Fibrodysplasia Ossificans Progressiva (FOP). * Symptomatic onset of a distinct flare-up within 7 days of Study Day 1 (start of study drug) and defined by the presence of at least two of six of the following symptoms: pain, soft tissue swelling, decreased range of motion, stiffness, redness, and warmth. Flare-up must be confirmed by the physician at the Screening visit. * Flare-up is at an appendicular area (upper or lower extremity), abdomen, or chest; and subject has received, is receiving, or is willing to receive treatment per standard of care, which may or may not include oral prednisone (2 mg/kg PO to a maximum dose of 100 mg daily) for 4 days. * Abstinent or using two highly effective forms of birth control. * Subjects must be accessible for treatment and follow-up. Subjects living at distant locations from the investigational site must be able and willing to travel to a site for the initial and all follow-up visits. Exclusion Criteria: * Weight \<20 kg. * Intercurrent non-healed fracture at any location. * Complete immobilization of joint at site of flare-up. * The inability of the subject to undergo imaging assessments using plain radiographs. * If currently using vitamin A or beta carotene, multivitamins containing vitamin A or beta carotene, or herbal preparations, fish oil, and unable or unwilling to discontinue use of these products for the duration of the study. * Exposure to synthetic oral retinoids in the past 30 days prior to Screening (signature of the informed consent). * Concurrent treatment with tetracycline due to the potential increased risk of pseudotumor cerebri. * History of allergy or hypersensitivity to retinoids or lactose. * Concomitant medications that are inhibitors or inducers of CYP450 3A4 activity. * Amylase or lipase \>1.5x above the upper limit of normal or with a history of chronic pancreatitis. * Elevated aspartate aminotransferase or alanine aminotransferase \>2.5x the upper limit of normal. * Fasting triglycerides \>400 mg/dL with or without therapy.

Locations (4)

University of California San Francisco, Division of Endocrinology and Metabolism

San Francisco, California, United States

University of Pennsylvania, Center for Research in FOP & Related Disorders

Philadelphia, Pennsylvania, United States

Hôpital Necker-Enfants Malades, Department of Genetics

Paris, France

The Royal National Orthopaedic Hospital, Brockley Hill

Stanmore, Middlesex, United Kingdom

Outcomes

Primary Outcomes

Percentage of Responders at Week 6

A responder was defined as a subject with no or minimal new heterotopic ossification (HO) at flare-up site versus baseline as assessed by plain radiographs at Week 6. Minimal new HO is defined as new HO with an HO score \<=3 in both anterior/posterior (AP) and lateral projections (or if one view is non-interpretable or non-evaluable, then remaining evaluable view is used). The HO score ranges from 0 to 6 where, 0 = no HO and 6 = single contiguous HO with longest dimension \>2 diameters of reference normotopic bone in any projection. The highest HO score from the 2 projections was used. Results from Primary Read reviews are presented. The Primary Read process included a double-read radiology review paradigm with consensus adjudication. Radiography and CT scans were examined independently by scan type, flare-up region, and imaging time point in order to determine whether radiography would be sufficient to measure new HO formation. Only subjects with interpretable outcomes were evaluated.

Time frame: Baseline (Day 1) and Week 6 (Day 42)

Secondary Outcomes

Percentage of Subjects With New HO at Weeks 6 and 12

Low dose CT scan was used as a secondary imaging assessment of HO and was performed at the same time points as plain radiographs. The percentage of subjects with new HO (regardless of the amount of new HO) at the flare-up site as assessed by CT scan and/or plain radiographs at Weeks 6 and 12 were analysed. The results are from Global Read reviews. The holistic Global Read process allowed concurrent review of all modalities across all time points, and provided access to selected clinical data at the time of review.

Time frame: Weeks 6 and 12 (Day 84)

Change From Baseline in Amount (Area) of New HO Formed at the Flare-up Site at Weeks 6 and 12

Interpretation of plain radiographs document the amount (area) of HO on both the AP and lateral radiograph views. The area for each view was a sum of all the new HO at the flare-up location (and thus if there are multiple HO lesions, the area of each lesion was determined and then the total across all lesions were summed to obtain a total new HO). This total new HO sum was used in the analysis of the area of new HO. Results from Primary Read reviews are presented.

Time frame: Baseline, Weeks 6 and 12

Percentage of Responders at Week 12

A responder was defined as a subject with no or minimal new HO at the flare-up site versus baseline as assessed by plain radiographs at Week 12. Minimal new HO is defined as new HO with an HO score \<=3 in both the AP and lateral projections (or if one view is non-interpretable or non-evaluable, then the remaining evaluable view is used). The HO score ranges from 0 to 6 where, 0 = no HO and 6 = single contiguous HO with longest dimension \>2 diameters of the reference normotopic bone in any projection. The highest HO score from the 2 projections was used. Results from the Primary Read reviews are presented. The Primary Read process included a double-read radiology review paradigm with consensus adjudication. Radiography and CT scans were examined independently by scan type, flare-up region, and imaging time point in order to determine whether radiography would be sufficient to measure new HO formation.

Time frame: Baseline and Week 12

Change From Baseline in Bone Specific Alkaline Phosphatase at Weeks 2, 4, 6 and 12

Blood and urine samples for analysis of cartilage, bone, angiogenesis, and inflammation biomarkers were collected. Bone specific alkaline phosphatase was analysed as a bone and cartilage biomarker.