Prader-Willi experts flag safety risks linked to Neurocrine's rare disease drug

Experts in Prader-Willi Syndrome on Tuesday raised safety concerns over Neurocrine's NBIX.O drug Vykat XR, citing serious adverse events reported in patients with the rare genetic disorder.

Vykat XR was approved last year to treat hyperphagia or feelings of intense and persistent hunger, the hallmark symptom of Prader-Willi syndrome, a genetic disorder caused by deletions on chromosome 15 that affect gene expression, or how genes turn on and off.

In a joint statement, Foundation for Prader-Willi Research and the International Prader-Willi Syndrome Organisation said serious adverse events - including edema, respiratory complications and cardiac complications - had been reported through post-marketing surveillance since Vykat XR became more widely available.

According to the statement, the U.S. Food and Drug Administration's Adverse Event Monitoring System (AEMS) showed seven reports of death linked to patients taking the drug as of July 31.

Peripheral edema and the drug being ineffective were the highest reported reactions on FDA's AEMS.

"VYKAT XR has a compelling risk-benefit profile in the context of a very serious disease. Neurocrine conducted extensive diligence on the safety profile, including adverse event data, during our process to acquire Soleno," said Neurocrine.

It added it is "engaged with the FDA, patient advocacy communities and prescribers to continue to assess all available data from postmarketing surveillance as the prescribing population expands."

Earlier this year, Neurocrine bought Soleno for $2.9 billion, gaining access to Vykat XR.

The joint statement said the reports were concerning and patients and families deserved transparency regarding the drug's safety profile.

They stressed, however, the reports do not establish a causal relationship between Vykat XR and the reported outcomes.