US FDA approves Acadia's genetic Rett syndrome drug

The US health regulator's decision allows use of the trofinetide, to be sold under the brand name Daybue, in adult and pediatric patients two years of age and older and comes with a warning of diarrhea and weight loss.

The approval comes months after the FDA declined to approve expanded use of Acadia's drug Nuplazid to treat psychosis related to Alzheimer's disease. Analysts have said approval of Daybue would help drive growth for the company in the near term.

"We have put a lot of planning into potential commercialization of trofinetide, including resources for patients to access the drug," said Acadia senior executive Kathie Bishop ahead of the approval.

Acadia said it plans to make the drug available to patients by the end of April. It did not disclose details of the price.

Before the approval, David Hoang SMBC Nikko Securities analyst estimated a list price at launch of $450,000 annually. He forecast peak US trofinetide sales of $487.2 million by 2035. RBC Capital Markets analyst Gregory Renza, also writing before the approval, predicted peak US sales to exceed $500 million by 2032 and an average annual launch price of about $425,000.

Acadia forecasts sales of Nuplazid - its only drug on the market - of between $520 and $550 million this year, above analysts' median expectations of $532.8 million, according to Refinitiv data. With the drugmaker facing a loss of exclusivity for Nuplazid in 2028, investors have pinned their hopes on a successful trofinetide launch.

After the FDA declined to approve the expanded use of Nuplazid, Acadia said it would not pursue that indication for Nuplazid further. The drugmaker plans to focus its resources on late-stage development of Nuplazid to treat symptoms of schizophrenia and early-stage development of another candidate, ACP-204, for Alzheimer's-related psychosis.

Rett's syndrome is a rare neurodevelopmental condition that occurs primarily in girls. According to government estimates, it affects fewer than 50,000 people in the US

Shares of the California-based company closed 0.68% lower on Friday.

Acadia's drug acts as an artificial form of the insulin-like growth factor IGF-1 and helps reduces inflammation in the nervous tissue as well as aid in the transmission of nerve impulses.

Acadia's application for marketing approval was based on data from a late-stage study in which treatment with the drug showed improvement in core symptoms of the disease compared to a placebo. Improvement of symptoms was measured according to the assessment scales Rett Syndrome Behavior Questionnaire and the Clinical Global Impression of Improvement.

The company had licensed the drug for $10 million up-front payment from Australian drugmaker Neuron Pharmaceuticals (NEU.AX) for development and sale in North America in 2018.

REUTERS