Ascendis Pharma A/S announced that the U.S. Food & Drug Administration (FDA) has accepted for Priority Review its New Drug Application (NDA) for TransCon PTH (palopegteriparatide) in adult patients with hypoparathyroidism and has set a Prescription Drug User Fee Act (PDUFA) target action date of April 30, 2023. TransCon PTH is an investigational prodrug designed to restore parathyroid hormone (PTH [1-34]) to physiological levels over 24 hours in adult patients with hypoparathyroidism. The FDA said that it is not currently planning to hold an advisory committee meeting to discuss the application.

Ascendis plans to submit a Marketing Authorisation Application (MAA) for TransCon PTH in adult patients with hypoparathyroidism to the European Medicines Agency (EMA) during the fourth quarter of this year. During the fourth quarter, the Company also expects to announce topline results for PaTHway Japan, the Phase 3 trial of TransCon PTH in adult Japanese patients with hypoparathyroidism. About Hypoparathyroidism (1, 2,) (3,) (4,) (5,) (6) Hypoparathyroidism is a rare endocrine disorder characterized by insufficient levels of parathyroid hormone (PTH), resulting in low calcium and elevated phosphate levels in the blood.

Hypoparathyroidism affects approximately 200,000 patients in the United States, Europe, and Japan, most of whom develop the condition following damage to or accidental removal of the parathyroid glands during thyroid surgery. Conventional therapy with calcium supplements and active vitamin D (also called calcitriol) does not effectively address the short-term symptoms, long-term complications, or quality-of-life impacts of hypoparathyroidism. Short-term symptoms include weakness, severe muscle cramps (tetany), abnormal sensations such as tingling, burning and numbness (paresthesia), memory loss, impaired judgment, and headache.

Patients often experience decreased quality of life, and, over the long term, this complex disorder can increase risk of major complications, such as calcium deposits in the brain, blood vessels, eye, and other soft tissues -- including the kidneys, which can lead to impaired renal function. Hypoparathyroidism remains among the few hormonal insufficiency states without a replacement therapy to restore the missing hormone at physiologic levels. Conventional therapy with high doses of calcium and active vitamin D does not fully control the disease or address its underlying cause and may contribute to risk of renal disease.

Patients with hypoparathyroidism have an estimated 4- to 8-fold greater risk of renal disease compared to healthy populations. Hypoparathyroidism is also associated with a 2-fold increased risk of depression or bipolar disorder compared to healthy populations.