The Food and Drug Administration approved Sohonos, Ipsen Pharmaceuticals’ ultra-rare bone disease drug, Wednesday evening.

The drug capsules are approved with an indication as a retinoid for reducing the volume of new heterotopic ossification in female patients over the age of 8 and male patients over the the age of 10 with fibrodysplasia ossificans progressiva (FOP).

The French drugmaker heralded the greenlight of the treatment, which reduces new, abnormal bone formation in soft and connective tissues for people living with the disease. Ipsen estimated that around 400 Americans suffer from FOP, which can lead to severe mobility loss, adversely impact quality of life and shorten median life expectancy to 56.

Approval from the FDA came after Ipsen released positive data from an 18-month Phase 3 trial of Sohonos at the end of 2022. The study found the drug reduced the heterotopic ossification volume compared with no treatment beyond standard of care and had a well-characterized safety profile.

“The FDA approval of Sohonos is a breakthrough for the U.S. FOP community. For the first time doctors have an approved medicine available to them, shown to reduce the formation of new, abnormal bone growth, known as heterotopic ossification (HO), which causes debilitating mobility challenges and has a devastating impact on the lives of people with FOP,” said Howard Mayer, Ipsen’s head of research and development, in a statement. “Development of medicines for rare diseases takes commitment and belief from everyone involved. We at Ipsen are sincerely grateful to the FOP community of patients and medical experts, as the first-ever treatment in the U.S. for managing FOP would not be possible without their participation in the clinical trials and ongoing support.”

Ipsen had been waiting on the FDA to take action on Sohonos following a vote in support of the drug by the Endocrinologic and Metabolic Drugs Advisory Committee. However, the European Medicine Agency’s Committee for Medicinal Products for Human Use confirmed a negative opinion on Sohonos as a potential treatment for FOP in May and it was not approved by the European Commission.

The FDA approval comes three weeks after Ipsen released its latest earnings report, highlighted by 7.2% growth in sales during the first half of the year. Subsequently, the company boosted its full-year financial guidance for total sales and core operating margin.

In mid-January, the biopharma also announced that it acquired Albireo Pharma for $952 million, gaining access to the company’s liver disease drug Bylvay. This treatment is approved in the U.S. and E.U. for treating pruritus in patients with progressive familial intrahepatic cholestasis.