Safety profile of pimavanserin therapy in elderly patients with neurodegenerative disease‐related neuropsychiatric symptoms: a Phase 3b study

Abstract

AbstractBackgroundPatients with neurodegenerative diseases including Parkinson’s disease often experience neuropsychiatric symptoms, including hallucinations and delusions, apathy, and agitation.1,2 These symptoms can greatly impair daily function and lead to reduced quality of life and significant caregiver burden. These patients are generally elderly and often frail. Treatment options are limited, representing a substantial unmet need. Pimavanserin, a 5‐HT2A receptor inverse agonist/antagonist, is FDA‐approved to treat hallucinations and delusions associated with Parkinson’s disease psychosis.3 MethodThis Phase 3b, multicenter, randomized, double‐blind, placebo‐controlled, parallel‐group study evaluated the safety of pimavanserin (34 mg) versus placebo in frail adults and elderly patients with neuropsychiatric symptoms related to neurodegenerative disease. The primary endpoint was safety and tolerability as measured by treatment‐emergent adverse events. Secondary safety endpoints included change from baseline in motor (Extrapyramidal Symptom Rating Scale‐Abbreviated [ESRS‐A]) and cognitive function (Mini‐Mental State Examination [MMSE]) at Week 8. Suicidality was assessed using the Columbia‐Suicide Severity Rating Scale (C‐SSRS) or Global Clinician Assessment of Suicidality (GCAS). Exploratory efficacy endpoints included Clinical Global Impression‐Severity (CGI‐S) and ‐Improvement (CGI‐I), 5‐level version of EQ‐5D (EQ‐5D‐5L), and Sleep Disorders Inventory (SDI).ResultOverall, incidence of TEAEs were similar between pimavanserin (n = 392) and placebo (n = 392); 29.8% reported ≥1 TEAE (pimavanserin: 30.4%; placebo: 29.3%) and 1.8% reported serious TEAEs (pimavanserin: 2.0%; placebo: 1.5%) (Table 1). TEAEs leading to discontinuation or study termination were reported in 2.6% and 2.3% of patients on pimavanserin and placebo, respectively. The most frequently reported TEAEs included urinary tract infection (pimavanserin: 6.4%; placebo: 4.1%) and headache (pimavanserin: 2.0%; placebo: 3.8%). Mortality due to TEAEs was similar between groups (0.5% each). Pimavanserin did not impact motor‐ or cognition‐related function (ESRS‐A and MMSE, respectively); an improvement was seen in CGI‐I (MMRM LSM [SE]: ‐0.2 [0.07], p = 0.0140] and sleep function (SDI) at Week 8 (MMRM LSM [SE]: ‐0.3 [0.06], p<0.0001] compared to placebo (Figures 1, 2); no differences were observed across other measures.ConclusionPimavanserin was well tolerated in patients with neuropsychiatric symptoms related to neurodegenerative disease, consistent with the known safety profile of pimavanserin, informing its use in Parkinson’s disease psychosis. Pimavanserin was not associated with cognitive decline or motor dysfunction.