Ipsen SA’s drug for a rare bone disease got support from a panel of US drug regulatory advisers, moving the first treatment for the condition closer to approval.

Advisers to the Food and Drug Administration voted 11-3 Wednesday that the benefits of the treatment, palovarotene, outweigh its risks. The FDA isn’t required to follow the recommendations of its advisers, but frequently does.

Ipsen shares rose as much as 6.3% in early Paris trading, the biggest gain in more than four months. The stock is up about 12% this year.

Ipsen’s drug treats fibrodysplasia ossificans progressiva, a very rare condition in which bone grows in tissues where it isn’t normally present. Muscles, tendons and soft tissue are gradually replaced by bone, slowly locking patients’ joints into place. Only about 800 people in the world are known to be affected, according to the US National Institutes of Health.

After an initial review, the FDA asked the French drugmaker for more follow-up data on the treatment last year. That pushed back the timeline on a decision by about six months, Bloomberg Intelligence estimated at the time. Many patient groups have contacted regulators to say how much a treatment is needed, Ipsen Chief Executive Officer David Loew said earlier this year.

Some panel members questioned the study Ipsen submitted in support of the drug, which wasn’t a gold-standard randomized, controlled design. Other members said the circumstances, including the rarity of the disease, made Ipsen’s data acceptable. In a separate vote, the panel said evidence from the study showed the drug was effective.

Loew, who became CEO in 2020, has been pouring billions of dollars into deal-making in order to reshape Ipsen’s pipeline amid declining revenue from its biggest product, cancer drug Somatuline. The company has about €2.5 billion ($2.7 billion) available to spend this year and next, Loew said in April.

(Updates with shares in third paragraph)