The death occurred in a patient who had a complex medical background and who was being managed with several drugs, according to RBC Capital.
The FDA’s surveillance system for drug toxicities reported that a patient on Ascendis Pharma’s hypoparathyroidism drug Yorvipath has died.
The monitoring mechanism, the FDA Adverse Event Reporting System (FAERS), only collects documented side effects associated with drugs; it cannot establish a conclusive and definitive link. “While FAERS contains reports on a particular drug or biologic, this does not mean that the drug or biologic caused the adverse event,” the FDA cautions on its website. “The FAERS data by themselves are not an indicator of the safety profile of the drug or biologic.”
After dipping as much as 12%, Ascendis ended Monday’s trading session 2.5% down from its prior closing price.
BioSpace has reached out to the company for comment.
Analysts at RBC Capital noted that the patient in question had breast cancer and a complex medical background, according to SeekingAlpha. The patient had been receiving several drugs, and it is unclear what role, if any, Yorvipath played in the death, RBC said.
Approved in August last year, Yorvipath is a long-acting prodrug of the parathyroid hormone that works by restoring normal levels of the hormone, in turn addressing the key symptoms of hypoparathyroidism: fatigue, weakness, muscle aches and, in more severe cases, abnormal bone growth and developmental delays.
While Monday’s FAERS flag does not alter Yorvipath’s established safety profile, it does fit with the theme of rough regulatory waters for the drug. Ascendis first attempted an approval for the drug in October 2022 but was rebuffed by the FDA in May 2023 due to manufacturing concerns. The agency at the time did not find problems with Yorvipath’s data package.
A resubmission was accepted in December 2023 but was met with a delay in May 2024—the same month the original action date was scheduled—to give the FDA more time to review a major amendment from Ascendis. It is unclear if the FAERS death will lead to regulatory action from the FDA.
Beyond Yorvipath, Ascendis is currently awaiting the FDA’s verdict for TransCon CNP, a prodrug therapy of the C-type natriuretic peptide, a signaling molecule that helps promote bone growth. Ascendis is proposing TransCon CNP as a weekly treatment for achondroplasia, the most common cause of dwarfism. The FDA has a target action date of Nov. 30.
