Daybue Now Available for the Treatment of Rett Syndrome

Credit: Acadia Pharmaceuticals.
Daybue is supplied as a strawberry-flavored oral solution; the product should be refrigerated.

Daybue (trofinetide) is now available for the treatment of Rett syndrome in adult and pediatric patients 2 years of age and older.

The product, which received FDA approval in March 2023, was approved based on data from the randomized, double-blind, placebo-controlled phase 3 LAVENDER study ( Identifier: NCT04181723). The study included female patients 5 to 20 years of age with Rett syndrome who were randomly assigned to receive trofinetide (n=93) or placebo (n=94) orally or via gastrostomy tube twice daily for 12 weeks. 

Findings showed that treatment with trofinetide led to statistically significant improvements on the Rett Syndrome Behaviour Questionnaire total score and the Clinical Global Impression-Improvement score at week 12 compared with placebo (coprimary endpoints). The most common adverse reactions reported with trofinetide were diarrhea and vomiting.

Commenting on the availability of Daybue, LAVENDER study investigator Alan Percy, MD, Professor of Pediatrics, Neurology, Neurobiology, Genetics, and Psychology at University of Alabama, Birmingham, said: “I am thrilled to now be able to offer Daybue to more people living with Rett syndrome, outside of a clinical trial. Having a therapy that has been shown to address multiple symptoms of Rett syndrome provides a promising treatment option that may lead to meaningful impact for patients and their families.”

Daybue is supplied as a strawberry-flavored oral solution containing 200mg of trofinetide per mL. The dosage is determined by patient weight and can be administered orally or via gastrostomy tube. A calibrated measuring device (eg, oral syringe, oral dosing cup) should be obtained from the pharmacy to measure and deliver the prescribed dose accurately.

Acadia is offering personal assistance to patients receiving Daybue through the Acadia Connect® program.


Acadia Pharmaceuticals announces Daybue (trofinetide) is now available for the treatment of Rett syndrome. News release. Acadia Pharmaceuticals. Accessed April 17, 2023.