French biopharmaceutical company Ipsen (Euronext Paris:IPN) (ADR:IPSEY) reported on Friday that its pivotal Phase II FALKON trial in fibrodysplasia ossificans progressiva (FOP) did not meet the primary endpoint of reducing new heterotopic ossification versus placebo, and the study will be closed.

The investigational therapy, fidrisertib, was generally well tolerated with no safety concerns observed.

Ipsen stated that the outcome was disappointing for patients but said the data will add to the scientific understanding of the disease and inform future management approaches. FALKON enrolled 113 patients globally and took more than five years to reach completion, reflecting a significant operational commitment.

FOP is an ultra-rare genetic disorder driven by pathogenic variants of the ALK2 kinase that cause irreversible bone formation in soft tissues. At present there are limited treatment options for patients with FOP.

Fidrisertib is an oral, highly selective ALK2 inhibitor designed to address both flare-up and non-flare-up bone formation associated with the disease.