Dive Brief:

• The Food and Drug Administration on Monday approved a hormonal replacement drug from Ascendis Pharma for a rare endocrine condition known as hypoparathyroidism.
• The drug, which Ascendis will sell as Yorvipath, is a prodrug formulation of the parathyroid hormone, levels of which are insufficiently low in the 70,000 to 90,000 people in the U.S. estimated to have the condition,
• Ascendis is still working on ramping up its manufacturing and plans to make supply of Yorvipath available in the first quarter of next year. Shares in Ascendis rose by as much as 10% Monday morning on the news.

Dive Insight:

A little over one year ago, Ascendis was hit with a complete response letter from the FDA, which denied its drug an approval over the company’s “manufacturing control strategy for variability of delivered dose.”

Ascendis resubmitted its application in November with an updated strategy, but then saw the agency delay its review by three months to review additional information submitted by the company.

Even now with an approval in hand, Ascendis has moved back its expectations for a market launch from the third quarter this year to the first quarter of next year. (However, it does plan to ask the FDA for an OK to commercialize some of its existing manufactured products, which would allow it to introduce Yorvipath in the fourth quarter.)

Manufacturing hiccups aside, the FDA granted Yorvipath a label that analysts described as “clean,” “broad” and containing “no surprises.” Specifically, the agency didn’t require a black box warning for the risk of osteosarcoma, which it did for two other drugs, Natpara and Forteo, that are also parathyroid hormone analogs.

Natpara, made by Takeda, has been the only prescription medicine available in the U.S. for hypoparathyroidism. But the company will stop making it available by the end of this year due to unresolved manufacturing issues.

The condition can cause low calcium levels and lead to a range of complications. Testing of Yorvipath, which is built around Ascendis “Transcon” drug delivery technology, showed treatment restored normal calcium levels. The drug was previously approved in Europe and the U.K.

Yorvipath is Ascendis’ second approved drug in the U.S.; the company also makes Skytrofa for pediatric growth hormone deficiency. The company told analysts that it hasn’t yet decided on the U.S. pricing for Yorvipath, which it sells for around $100,000 per year in Europe.