Effect of Adjunctive Pimavanserin on Sleep/Wakefulness in Patients With Major Depressive Disorder

Abstract

ABSTRACT Objective: This was an analysis of pimavanserin, a 5-hydroxytryptamine 2A antagonist/inverse receptor agonist, on dysregulated sleep in patients with major depressive disorder (MDD) by DSM-5 criteria and an inadequate antidepressant response.

Methods: For this analysis of CLARITY, a Phase 2 study of adjunctive pimavanserin, sleep/wakefulness disturbances were measured with the sum of Hamilton Depression Rating Scale (HAMD) insomnia items (Items 4, 5, and 6) and the Karolinska Sleepiness Scale (KSS). Outcomes included change from baseline for HAMD insomnia score >3, correlation between the HAMD insomnia score and KSS, and change from baseline for the Sheehan Disability Scale (SDS) and Unproductive Days subscore in patients with a baseline KSS >6.

Results: The study was conducted between December 2016 and October 2018. At baseline, HAMD insomnia factor score >3 occurred in 76% with placebo and 85% with pimavanserin. The overall LS mean (standard error) weighted difference was -0.5 (0.32) with a 95% confidence interval (CI) -1.2 to, 0.1 (p=0.088) at Week 5. Improvement was observed with pimavanserin vs. placebo at Weeks 2, 3, and 4, with effect sizes of 0.370 to 0.524 (p<0.05). For KSS, the LS mean difference at Week 5 was -1.1 (0.30), 95% CI -1.7 to, -0.5 (p=0.0003; effect size: 0.627) for pimavanserin vs. placebo. Among those with a KSS >6 at baseline (n=120 placebo and n=42 pimavanserin), the LS mean difference in the SDS mean score at Week 5 was -1.1 (0.46), 95% CI -2.0 to, -0.2 (p=0.019; effect size: 0.442) for pimavanserin vs. placebo.

Conclusions: Adjunctive pimavanserin significantly improved sleep/wakefulness sleep disturbance during treatment of MDD, which was associated with greater improvement in function. This study was registered at clinicaltrials.gov: NCT03018340.

Key Words: insomnia, major depressive disorder, pimavanserin, sleep