Horizon Pharma’s Actimmune has been placed on a fast-track pathway by the US Food and Drug Administration, potentially speeding up its development for the degenerative neuro-muscular disorder Friedreich's ataxia.

The move signals the regulator’s belief that the treatment has the potential to address a currently unmet medical need, given that there are as yet no approved therapies to treat the condition, which affects around one in 50,000 in the US.

Actimmune (interferon gamma-1b), a biologically manufactured protein similar to one the body makes naturally to help prevent infection, has already picked up US approval for use in Chronic Granulomatous Disease and severe, malignant osteopetrosis.

Phase III trials in patients with FA are scheduled to begin sometime this quarter.