Long-term Safety, Efficacy, Treatment Satisfaction, and Impact on Healthcare Service Use of Paliperidone Palmitate One-month Intramuscular Formulation in Patients with Recent-onset Schizophrenia in Taiwan: A Subgroup Analysis of an Asia-Pacific, 18-month, Phase 3b Study

Long-term Safety, Efficacy, Treatment Satisfaction, and Impact on Healthcare Service Use of Paliperidone Palmitate One-month Intramuscular Formulation in Patients with Recent-onset Schizophrenia in Taiwan: A Subgroup Analysis of an Asia-Pacific, 18-month, Phase 3b Study

Objectives: In this study, the authors intended to evaluate the efficacy and safety of paliperidone palmitate 1-month injection (PP1M) in patients with recent-onset schizophrenia (SCH). Methods: A subgroup analysis was done for patients enrolled in Taiwan in an Asia-Pacific, Phase 3b study (ClinicalTrials.gov identifier NCT01051531). Patients were switched from oral antipsychotics to intramuscular PP1M. Results: We included 61 patients (age: 31.2 ± 8.8 years). The Positive and Negative Syndrome Scale scores were significantly decreased, with the largest effect size observed in positive, disorganized, and depressive factors (Cohen's d = 0.52, 0.52, and 0.79, respectively). Most symptoms stabilized within six months, whereas stabilization of functional improvement required 1-1.5 years of PP1M treatment, especially for employment/ academic status. PP1M treatment was well-tolerated, with over 70% of treatment satisfaction rate, and significantly reduced the average days of hospitalization (43.3-7.1/person-years). Conclusion: Switching to PP1M improved treatment outcome and satisfaction as well as reduced healthcare service use in patients with recent-onset SCH.