Real-World Outcomes Post-Transition to Once-Every-Three-Month Paliperidone Palmitate in Patients With Schizophrenia Within US Commercial and Managed Care Plans

Background: Medication non-adherence is common for patients with schizophrenia. Decreasing dosing frequency of patients adequately treated with once-monthly paliperidone palmitate (PP1M) to once-every-three-month paliperidone palmitate (PP3M) may lead to better adherence and outcomes.

Objectives: To compare patient characteristics, adherence to antipsychotics, healthcare resource utilization (HRU), and costs pre- and post-transition to PP3M.

Methods: Adults with ≥1 claim for PP3M, ≥2 schizophrenia diagnoses, and prior adequate treatment with PP1M were selected from the IQVIATM PharMetrics Plus database (05/2014-02/2018). Generalized estimating equation models adjusted for repeated measurements were used to compare patient characteristics, adherence to antipsychotics, HRU, and costs during the 6-month period (12-month sensitivity) pre- versus post-transition to PP3M.

Results: Among 152 patients who transitioned to PP3M, the mean age was 41.0 years and 36.2% were females. Post-PP3M transition, patients were less likely to have a diagnosis for a co-morbid substance or addictive disorder (odds ratio [OR]=0.57, p-value<0.001) and more likely to be adherent to antipsychotics (OR=2.01, p-value=0.007), compared to the period pre-PP3M transition. Post-PP3M transition, patients had numerically fewer all-cause emergency room visits (rate ratio [RR]=0.92, p-value=0.381) and inpatient admissions per month (RR=0.63, p-value=0.433). All-cause total (mean monthly cost difference [MMCD]=$242, p-value=0.120), pre-rebate pharmacy (MMCD=$65, p-value=0.140), and medical costs (MMCD=$176, p-value=0.284) remained similar pre- versus post-transition. Results were similar using 12 months pre- and post-transition.  

Conclusions: Transitioning to PP3M was associated with a reduction in comorbidities, an improvement in adherence, and a numerical reduction in HRU. These findings suggest PP3M may increase quality of care, while remaining cost neutral.