Clinical stage biopharmaceutical company Clementia Pharmaceuticals has received orphan drug designation from the US Food and Drug Administration (FDA) for its palovarotene to treat fibrodysplasia ossificans progressive (FOP).

Clementia chief development officer Jeff Packman said: "Following the recent initiation of our Phase II clinical study, we are pleased to receive orphan drug designation for palovarotene and believe this represents an important regulatory milestone for our development programme."

The company initiated the Phase II clinical trial of palovarotene, a retinoic acid receptor gamma agonist, on 14 July.

"Following the recent initiation of our Phase II clinical study, we are pleased to receive orphan drug designation for palovarotene and believe this represents an important regulatory milestone for our development programme."

The double-blind, placebo-controlled clinical trial will assess the effect of different doses of palovarotene on new bone formation during and after a flare-up in 24 FOP patients who are 15 years of age or older.

A number of clinical endpoints will assess the efficacy and safety of palovarotene, including imaging endpoints for new bone formation and clinical assessments of physical function and patient-reported outcomes.

Palovarotene has been shown to block bone formation in a variety of mouse models of heterotopic ossification. The Phase II clinical trial has been designed to determine whether the effects seen in these mouse models could be recapitulated in FOP patients.

The company anticipates completing the clinical trial during 2015.

Palovarotene has been in-licensed from Roche in 2013 where the drug was previously evaluated in more than 800 individuals, including healthy volunteers and patients with chronic obstructive pulmonary disease.