Once-monthly injection of paliperidone palmitate in patients with recently diagnosed and chronic schizophrenia: a post-hoc comparison of efficacy and safety

Background: The use of long-acting injectable antipsychotics in recently diagnosed schizophrenia remains less explored. We evaluated the efficacy and safety of paliperidone palmitate once-monthly (PP1M) treatment in adult patients with recently diagnosed vs. chronic schizophrenia. Research design and methods: These post-hoc analyses included two multicenter studies. Study 1 (NCT01527305) enrolled recently diagnosed (<= 5 years) and chronic (>5 years) patients; Study 2 (NCT01051531) enrolled recently diagnosed patients only. Recently diagnosed patients were further sub-grouped into <= 2 years or 2-5 years. The primary efficacy endpoint was the change from baseline in Positive and Negative Syndrome Scale (PANSS) total score. Results: In Study 1, 41.5% patients had recent diagnosis (<= 2 years: 56.8%; 2-5 years: 43.2%); 58.5% had chronic schizophrenia. In Study 2, 52.8% and 47.2% patients were grouped into <= 2 years and 2-5 years, respectively. PANSS total score showed significantly greater improvement in patients with recently diagnosed vs. chronic schizophrenia. Similar results were obtained for PANSS responder rate, improvements in PANSS, and CGI-S scores. Conclusion: PP1M was efficacious in both recently diagnosed and chronic schizophrenia, with the benefits being more pronounced in patients with recently diagnosed schizophrenia. This adds to growing evidence recommending long-acting antipsychotic interventions at early stages of schizophrenia.