Health Canada approves Daybue for Rett syndrome in patients aged 2 years and older

Health Canada has approved Daybue to treat Rett syndrome in patients aged 2 years and older, according to manufacturer Acadia Pharmaceuticals.

In a press release, the company said that approval of Daybue (trofinetide) was based on positive safety and efficacy results from the phase 3 LAVENDER study, which included 187 girls and young women diagnosed with the rare neurological disorder. About 600 to 900 600 to 900 individuals are estimated to have the disorder in Canada.

According to the release, treatment with Daybue led to statistically significant changes in the study’s co-primary endpoints of change from baseline in both the Rett Syndrome Behaviour Questionnaire (RSBQ) total score as well as Clinical Global Impression-Improvement (CGI-I) scale score at week 12 compared with placebo.

In addition, per the release, significant change was observed from baseline to week 12 for a secondary endpoint of Communication and Symbolic Behavior Scales Development Profile Infant-Toddler Checklist – Social Composite Score compared with placebo.

In March 2023, the FDA approved Daybue as the first and only treatment for Rett syndrome in the U.S.

Trofinetide is a synthetic analog of the N-terminal tripeptide of insulin-like growth factor 1, whose mechanism of action for therapeutic effect on those with Rett syndrome is still unknown, the company said in the release.

“Health Canada’s authorization is a significant milestone for the Rett syndrome community in Canada and another step forward in Acadia’s commitment to increase access to this therapy for patients and their families,” Acadia CEO Catherine Owen Adams said in the release. “We look forward to bringing Daybue to Canadian patients with Rett syndrome as soon as possible.”