Rationale: Long-acting injectable (LAI) paliperidone palmitate 1-month formulation (PP1M) has demonstrated acceptable tolerability and favorable clinical outcomes in Western and Asian patients with schizophrenia. Hence, analysis of the outcomes of long-term PP1M treatment specifically in Chinese patients is of interest.
Objective: The aim of this study is to evaluate the long-term safety and efficacy of PP1M treatment in Chinese patients with schizophrenia.
Methods: In this 25-week, open-label, Phase IV study, patients (18-65 years) diagnosed with schizophrenia and having a baseline Positive and Negative Syndrome Scale (PANSS) total score of 60-120 (inclusive) were enrolled. All patients received injections of PP1M 150 mg eq. (day 1) and 100 mg eq. (day 8), followed by a flexible once-monthly maintenance dosing (75, 100, or 150 mg eq.).
Results: Of the 353 patients, 234 (66.3%) completed the study treatment (mean age, 31.1 years; 52.7% men). The PANSS total score (primary end point) improved significantly over the 6-month treatment period (mean [standard deviation] change from baseline to end of treatment, -27.2 [18.30]; P<0.0001). The Clinical Global Impressions-Severity and Personal and Social Performance scores (secondary end points) also improved significantly (P<0.0001). At 6 months, PP1M had a positive impact on medication satisfaction, adherence, and increased preference for LAIs. Treatment-emergent adverse events (TEAEs) were reported by 181 (51.3%) patients (TEAEs ≥5%: extrapyramidal disorder [15.3%], akathisia [10.5%], blood prolactin increase [8.8%], insomnia [5.4%]). A total of 8 deaths were reported, including 4 completed suicides.
Conclusion: Long-term treatment with PP1M was efficacious, and no new safety concerns were identified in Chinese patients with schizophrenia. Overall, the results were comparable with observations from previous studies.
Keywords: Chinese; PANSS; long-acting injectables; open-label; paliperidone palmitate; schizophrenia.