Clinical Experience with Pimavanserin for Treatment of Parkinson’s Disease Psychosis (P1.040)

Objective: To report the clinical experience using pimavanserin for Parkinson’s disease (PD) psychosis in a large ambulatory clinical setting. Background: Pimavanserin, a 5HT2A inverse agonist, was recently approved by the FDA for the treatment of PD psychosis, but there are few reports on real-world clinical experience. Here, we sought to evaluate prescribing patterns and clinical efficacy in a large convenience cohort. Design/Methods: We performed a retrospective chart review, identifying patients prescribed pimavanserin between May 2016 and August 2017. Medical records were reviewed to determine clinical presentation, concomitant medications, medication effectiveness, and side effects. Results: Pimavanserin was prescribed to 70 patients, and 59 of these began treatment. Most were male (76%), and mean age was 71 years +/− 8. Treatment indications were visual hallucinations (97%), where 39 (66%) experienced concomitant delusions, and 2 patients (3%) had delusions only. Most (n=39) had persistent symptoms despite a previous trial of one or more other antipsychotics (quetiapine=34, clozaril=9, atypical antipsychotic=6), while in 20 pimavanserin was first line therapy. Of the 39 who previously trialed an antipsychotic, 11 discontinued the antipsychotic prior to starting pimavanserin, 10 titrated gradually off of their antipsychotic (21.6 days +/− 7.4) after starting pimavanserin, and 18 continued or restarted another antipsychotic in concert with pimavanserin initiation. Most patients (n=50) tolerated pimavanserin without significant side effects. The most common side effect was worsening gait instability and weakness (n=5). Most patients reported clinical improvement (n=42). Of the 37 still taking pimavanserin, 14 are taking quetiapine concomitantly (median daily dose= 25 mg) and 1 is taking olanzapine. Of the 20 that failed pimavanserin, only 5 out of 20 achieved subsequent symptom improvement on a different antipsychotic. Conclusions: This study provides relevant clinical data on prescribing patterns of pimavanserin in a large PD cohort. Future studies will assess patient characteristics that predict medication efficacy. Disclosure: Dr. Sellers has nothing to disclose. Dr. Darby has nothing to disclose. Dr. Claassen has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Teva Neuroscience, Lundbeck, Acadia, AbbVie. Dr. Claassen has received research support from NIH/NINDS, Michael J. Fox Foundation, Huntington Disease Society of America, Vaccinex, AbbVie, Auspex Pharmaceuticals.