Comparing Relapse Rates in Real-World Patients with Schizophrenia Who Were Adequately versus Not Adequately Treated with Paliperidone Palmitate Once-Monthly Injections Before Transitioning to Once-Every-3-Months Injections.

PURPOSE

This retrospective cohort study evaluated real-world data on relapses in adult patients with schizophrenia who transitioned to long-acting injectable paliperidone palmitate once-every-3-months (PP3M) following treatment with once-monthly paliperidone palmitate (PP1M).

PATIENTS AND METHODS

Data derived from the IBM MarketScan Multi-State Medicaid Database were analyzed. Adults aged ≥18 years with ≥1 schizophrenia diagnosis claim and ≥12 months of continuous medical and prescription enrollment before and/or at index date of PP3M were eligible for inclusion. Patients were matched on propensity score to 2 PP3M cohorts: (1) adequately treated (AT), defined as patients treated with PP1M for ≥4 months, with the last 2 doses the same and a PP3M initiation dose meeting the corresponding PP1M-to-PP3M dose conversion, or (2) not adequately treated (NAT), defined as patients who received ≤2 or no PP1M doses. Relapse rates and time to relapse distributions based on the first occurrence of a qualifying event during the 2-year follow-up period were compared between PP3M cohorts using Kaplan-Meier survival curves and log rank test statistics. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards models. Two sensitivity analyses using different matched populations were performed to assess the robustness of the primary findings.

RESULTS

Propensity score matching yielded a sample of 1314 patients (657 per group). Most patients were male (68.9%) and aged 25-64 years (90.1%). The relapse rate was significantly lower in the AT (18.4%) versus NAT cohort (26.8%), P = 0.0002. Risk of relapse decreased by 35% for AT versus NAT (HR: 0.65 [95% CI: 0.51-0.81]). Relapse reductions favored the AT cohort in both sensitivity analyses (HR: 0.67 [95% CI: 0.54-0.83] and HR: 0.74 [95% CI: 0.56-0.97]).

CONCLUSION

In this analysis of Medicaid claims data, patients adequately treated with PP1M before transitioning to PP3M demonstrated significantly lower relapse rates and delayed time to relapse.