FDA delays review of Ascendis hypoparathyroidism drug

May 15, 2024

The U.S. FDA has extended the PDUFA goal date for Ascendis Pharma's TransCon PTH by three months, tacking on more delays to the already once-rejected hypoparathyroidism treatment.

With a new goal date of August 14, the extension follows Ascendis' submission of additional information, which the FDA deemed a major amendment requiring further review.

The company was handed a complete response letter for TransCon PTH in May 2023, with the FDA citing concerns related to the manufacturing control strategy for variability of delivered dose in the drug/device combination product. After meeting with the FDA, Ascendis resubmitted its NDA in November.

The efficacy and safety of TransCon PTH have been evaluated in multiple clinical trials, including the phase 3 PaTHway trial. The PaTHway trial included 84 adult patients with chronic hypoparathyroidism who were randomized to receive either TransCon PTH or placebo. The study showed that patients treated with TransCon PTH experienced a marked increase in serum calcium levels and a reduction in the need for active vitamin D and calcium supplements. 

Hypoparathyroidism is a condition where the body produces insufficient parathyroid hormone, leading to low calcium levels and high phosphate levels in the blood. TransCon PTH works via a unique mechanism of action involving the sustained release of a parathyroid hormone (PTH) analog. The drug is designed to provide a steady level of PTH over 24 hours, mimicking the natural hormone's effects more closely than current treatments. This continuous delivery aims to maintain stable calcium and phosphate levels, thereby improving the quality of life for patients with hypoparathyroidism.

Earlier this month, Amolyt Pharma revealed that its phase 3 therapeutic peptide candidate for treating hypoparathyroidism had been granted Fast Track designation. The drug, eneboparatide, was a driving force behind AstraZeneca's $1.05 billion acquisition of Amolyt back in March.