Canada-based Clementia Pharmaceuticals has started a Phase II extension trial of palovarotene, an investigational retinoic acid receptor gamma agonist, to treat patients with fibrodysplasia ossificans progressiva (FOP), a rare and severely disabling genetic disease.
FOP is characterised by painful, recurrent episodes of soft tissue swelling (flare-ups) and new abnormal bone formation and this process called heterotopic ossification (HO), occurs in muscles, tendons and ligaments, causing significant morbidities and progressive disability.
The company said that patients who completed its 12-week, randomised, double-blind, placebo-controlled Phase II trial of palovarotene in FOP are only eligible to participate in this multi-centre, open-label extension trial.
The Phase II extension trial does not include any placebo arm, therefore all the patients will be treated with palovarotene to assess its long-term safety and efficacy in FOP.
University of California San Francisco (UCSF) School of Medicine assistant professor and one of the principal investigators in the extension study Edward Hsiao said: "Continuity of care is a high priority for patients with FOP because the disease is progressive and debilitating, with unpredictable flare-ups.
"The extension trial provides access to palovarotene if patients experience flare-ups over the ensuing 12 months."
The company has in-licensed palovarotene from Roche Pharmaceuticals, where it was previously assessed in more than 800 individuals including healthy volunteers and patients with chronic obstructive pulmonary disease.
Clementia chief medical officer Donna Grogan said: "Providing continued access to palovarotene through this extension study is important for those patients who agreed to participate in the previous trial, which included the possibility of receiving either placebo or palovarotene treatment at the time of a flare-up.
"We are focused on understanding the role of palovarotene as a potential treatment for FOP, and on understanding the long-term effects of treatment. This study will advance our knowledge base in this area."