Open-Label Study of Pimavanserin Patients With Comorbid Parkinson’s Disease and Depression

Depression occurs in ~50% of Parkinson’s disease (PD) patients, increases in severity as the disease progresses, and is associated with increased morbidity. We are assessing use of pimavanserin (PIM) for treatment of depression in adults with PD. A Phase-2, 8-week, open-label, single-arm safety and efficacy study is evaluating PIM as an adjunct to SSRI/SNRI or as monotherapy in adults (n=40 planned) with PD and symptoms of depression (baseline Hamilton Depression Scale [17-items] total score [HAMD-17] ≥15). Interim results are based on the first 34 patients evaluated. 55.9% were male, and average age was 68.1 years, with n=19 on adjunctive therapy, n=15 on monotherapy. Baseline mean(SE) HAMD-17 was 19.8(0.6). Change from Baseline to Week 8 (least squares mean [SE]) in the HAMD-17 (primary endpoint) was –10.7[1.0] (P < 0.001), with significant improvement by Week 2 (–8.4[1.0];P < 0.001). Significant improvement was seen for adjunctive and monotherapy: at Week 8, 45.2% showed ≥50% improvement in the HAMD-17, and 35.5% reached remission (HAMD-17 ≤7); on the Clinical Global Impressions–Improvement scale, 54.8% were much/very much improved. Significant improvement was seen in Scales of Outcomes in PD-Sleep–Global Sleep Quality, –Nighttime Sleep, and –Daytime Sleepiness: –1.0[0.4], P=0.010; –2.1[0.7], P=0.008; and –2.1[0.4], P < 0.001, respectively. Thirteen patients reported adverse events, the most common being falls, UTI, diarrhea, and nausea. Pimavanserin as adjunctive or monotherapy was associated with early sustained improvement of depressive symptoms in patients with PD, and well tolerated. Additional placebo-controlled data are needed to confirm these findings.

This poster was presented at the 32nd annual Psych Congress, held Oct. 3-6, 2019, in San Diego, California.