By Sneha S K and Sriparna Roy

Aug 12 (Reuters) - Ascendis Pharma ( ASND ) said on

Monday the U.S. Food & Drug Administration had approved its

therapy to treat adult patients with a hormone disorder, sending

the Danish drugmaker's shares more than 10% higher in premarket

trading.

Ascendis's Yorvipath, will become the only approved

treatment for the condition, called hypoparathyroidism, in the

United States after rival Takeda stops manufacturing

its injection, Natpara, at the end of this year due to supply

issues.

The approval for Yorvipath comes after a couple of setbacks

- including an extension of FDA review in May, and a rejection

of approval last year, on concerns linked to manufacturing

controls of the drug and device combination.

The company's mid- and late-stage studies showed the

majority of the patients treated with Yorvipath did not need to

take vitamin D and calcium supplements daily - which are the

current standard-of-care treatments for hypoparathyroidism.

It is a rare endocrine disease caused by low levels of

parathyroid hormone that impact multiple organs and affects an

estimated 70,000 to 90,000 people in the United States,

according to the company.

Low production of parathyroid hormone in hypoparathyroidism

leads to abnormally low calcium levels in the blood and an

increase of phosphorus.

Ascendis anticipates initial supply of the once-daily

therapy will be available in the first quarter of 2025, and

expects to announce the annual price of the therapy in the

coming week.

Evercore ISI analyst Gavin Clark-Gartner estimates peak

sales to be about $2.5 billion on an adjusted basis and expects

the therapy to have a market penetration of about 12.5% in the

United States.

Ascendis also plans to request FDA's approval to

commercialize existing manufactured products qualified for other

markets, which if approved, could be introduced in the United

States in the fourth quarter of 2024.