A 16-Week Open-Label Study of the Effects of Treatment With Pimavanserin on Activities of Daily Living in Subjects With Parkinson’s Disease Psychosis

Abstract

Introduction

Accurate assessment of disability associated with Parkinson’s Disease Psychosis (PDP) is essential and has been poorly studied. Patients often have poor insight on impact of PDP on daily function. This phase 4 study is the first to evaluate the impact of pimavanserin on activities of daily living (ADL) in PDP patients.

Methods

Eligible PDP patients entered a 16-week single-arm, open-label study of oral pimavanserin (34 mg) taken once daily. Primary endpoint (modified Functional Status Questionnaire [mFSQ]) and secondary endpoints (MDS-UPDRS I & II; Schwab and England ADL; CGI-S, CGI-I, and PGI-I) were measured as change from baseline to Week 16 using mixed-effects model for repeated measures (MMRM) and least-squares means (LSM).

Results

29 patients were treated with pimavanserin, of which 24 (82.8%) completed the study. Treated patients demonstrated significant improvements in LSM (SE) mFSQ score change from baseline to Week 12 (11.5 [2.44]) and Week 16 (14.0 [2.50]; both p<0.0001). Significant improvements (p<0.05) were also observed for all secondary outcomes at Week 16 (MDS-UPDRS Part I: -6.3 [0.97]; MDS-UPDRS Part II: -2.6 [0.98]; CGI-S: -1.5 [0.25]; CGI-I: 1.9 [0.17]; PGI-I: 2.0 [0.22], except for Schwab and England ADL. No new safety signals were observed.

Conclusion

Functional outcomes and psychosis measures improved in PDP patients treated with pimavanserin, with safety findings consistent with previous studies. Our findings highlight the positive effect of pimavanserin in improving ADLs in patients with PDP.

Funding

Acadia Pharmaceuticals Inc.