FDA Reports Death in Patient on Ascendis Pharma's Yorvipath, Raising Safety Concerns

The pharmaceutical industry faces renewed scrutiny as the U.S. Food and Drug Administration (FDA) reports a patient death associated with Ascendis Pharma's hypoparathyroidism drug, Yorvipath. This development has sent ripples through the market and raised questions about the drug's safety profile.

FDA Adverse Event Report and Market Response

The FDA Adverse Event Reporting System (FAERS) has documented the death of a patient who was taking Yorvipath, Ascendis Pharma's long-acting parathyroid hormone prodrug. This news caused Ascendis's stock to fluctuate, with shares initially plummeting by 12% before recovering to close 2.5% down from the previous trading session.

It's crucial to note that the FAERS system collects reports of adverse events but does not establish causal relationships between drugs and reported incidents. The FDA explicitly states on its website that FAERS data alone "are not an indicator of the safety profile of the drug or biologic."

Patient Background and Analytical Perspective

According to analysts at RBC Capital, the deceased patient had a complex medical history, including breast cancer, and was being treated with multiple medications. This complicates the assessment of Yorvipath's potential role in the patient's death. The analysts emphasized that the relationship between the drug and the adverse event remains unclear.

Yorvipath, approved in August 2024, is designed to restore normal parathyroid hormone levels in patients with hypoparathyroidism. The drug addresses symptoms such as fatigue, weakness, and muscle aches, with more severe cases potentially involving abnormal bone growth and developmental delays.

Regulatory Challenges and Future Outlook

This latest development adds to a series of regulatory hurdles for Yorvipath. Ascendis Pharma's initial approval attempt in October 2022 was rejected by the FDA in May 2023 due to manufacturing concerns, despite no issues with the drug's data package. A subsequent resubmission in December 2023 faced delays in May 2024 as the FDA requested more time to review a major amendment from Ascendis.

As the industry awaits potential regulatory action following the FAERS report, Ascendis Pharma is also anticipating an FDA decision on another product, TransCon CNP. This weekly treatment for achondroplasia, the most common cause of dwarfism, has a target action date of November 30.

The pharmaceutical community will be closely monitoring these developments, as they could have significant implications for Ascendis Pharma and the broader landscape of rare disease treatments.