FDA approves first Rett syndrome treatment for adult, pediatric patients

The FDA has approved Daybue for the treatment of Rett syndrome in patients aged 2 years and older, making it the first and only approved treatment for the genetic disorder, according to an Acadia Pharmaceuticals press release.

The approval of Daybue (trofinetide, Acadia) was based on safety and efficacy data from the phase 3 LAVENDER study, which enrolled 187 female patients with Rett syndrome aged 5 to 20 years. According to the release, trofinetide demonstrated significant improvement from baseline in Rett Syndrome Behavior Questionnaire and Clinical Global Impression-Improvement scores compared with placebo at week 12. The most common side effects were diarrhea (82%) and vomiting (29%).

“As the first FDA-approved drug for the treatment of Rett syndrome, Daybue now offers the potential to make meaningful differences in the lives of patients and their families who have lacked options to treat the diverse and debilitating array of symptoms caused by Rett syndrome,” Acadia CEO Steve Davis, JD, said in the release. “We are grateful to all of the Rett syndrome patients, caregivers, clinical investigators and our employees who have contributed to making today a reality and look forward to getting Daybue to patients as quickly as possible.”

The FDA accepted the new drug application for trofinetide in September, and the drug is expected to be available in the United States by the end of April 2023, the company stated.