Full Results from LAVENDER Study Confirm Benefits of Daybue to Treat Rett Syndrome Symptoms

According to new results of the LAVENDER study published in Nature Medicine, Daybue (trofinetide, Acadia Pharmaceuticals Inc., San Diego, CA) may be effective in treating and improving core symptoms of Rett syndrome in female patients.

The LAVENDER trial was a phase 3, 12-week, double-blind, randomized, placebo-controlled study evaluating the safety, efficacy, and tolerability of Daybue in treating Rett syndrome in 187 female participants aged 5-20 years from 21 sites across the United States. Patients were randomized to take placebo (n = 94) or Daybue (n = 93) by weight-based dosing orally or by gastronomy tube twice per day. Co-primary endpoints were least squares mean (LSM) change in Rett Syndrome Behaviour Questionnaire (RSBQ) and Clinical Global Impression-Improvement (CGI-I) score. A mixed-effects model for repeated measures (MMRM) was used to determine that at week 12, the LSM treatment difference in Daybue vs placebo was -3.1 (95% CI, -5.7 to -1.6; P=.0175) for RSBQ and -0.3 (95% CI, -0.5 to -0.1; P=.0030) for CGI-I. These results suggest that participants’ Rett syndrome symptoms improved on Daybue relative to placebo. Results for a key secondary endpoint, the Communication and Symbolic Behavior Scales Development Profile Infant-Toddler Checklist (CSBS-DP-IT) further indicated improvement on Daybue relative to placebo (1.0 [95% CI, 0.3 to 1.7; P=.0064]. No deaths were reported, and 3 participants (3.2%) in each group experienced serious treatment emergent adverse events (TEAEs).

“The publication of the efficacy and safety results for DAYBUE reinforces the significance of this study as a critical advancement in Rett syndrome research, furthering our ability to treat this devastating disease,” said Jeffrey L. Neul, MD, PhD, LAVENDER study lead author.

Rett syndrome is a rare neurodevelopmental disorder affecting approximately 6000-9000 patients in the United States associated with impairments in communication, coordination, and motor control in the hands.