Paliperidone Palmitate 3-Monthly Versus 1-Monthly Injectable in Patients With Schizophrenia With or Without Prior Exposure to Oral Risperidone or Paliperidone: A Post Hoc, Subgroup Analysis.

Background And Objective: Paliperidone palmitate 3-monthly (PP3M) injectable formulation offers an advantage of improved medication adherence and lower relapse risk in patients with schizophrenia. This post hoc analysis compared outcomes following PP3M versus paliperidone palmitate 1-monthly (PP1M) treatment in patients with schizophrenia treated/untreated with oral risperidone/paliperidone (RIS/PALI).

Methods: Patients were treated with PP1M (50, 75, 100, or 150 mg equivalent [eq.]) for 17 weeks during an open-label (OL) phase and randomized (1:1) to PP3M (175, 263, 350, or 525 mg eq.) or PP1M (50, 75, 100, or 150 mg eq.) during a 48-week double-blind phase. Efficacy outcomes were compared based on prior oral RIS/PALI exposure: recent (≥ 28 days of oral RIS/PALI exposure with last dose within 14 days before study entry); or no (no oral RIS/PALI exposure within 60 days before study entry).

Results: A total of 452 OL patients received recent oral RIS/PALI (n = 323 [71%], randomized to PP3M = 166; PP1M = 157), and 709 OL patients were without recent oral RIS/PALI (n = 506 [71%], randomized to PP3M = 254; PP1M = 252). Improvements in Positive and Negative Syndrome Scale (PANSS) scores (OL baseline-to-endpoint) were similar in recent-RIS/PALI (mean [standard deviation]:18.3 [17.96]) and no-RIS/PALI (- 21.1 [16.40]) subgroups. Relapse-free rates were comparable between recent-RIS/PALI (relapse-free rate [95% confidence interval for difference]: 2.6 [- 4.7 to 10.0]; PP3M: 90%; PP1M: 87%) and no-RIS/PALI subgroups (0.8 [- 4.5 to 6.0]; PP3M: 92%; PP1M: 91%). Weight gain was the most common (> 5% incidence) treatment-emergent adverse event in both subgroups irrespective of the prior treatment.

Conclusion: Patients with schizophrenia, irrespective of prior treatment with RIS/PALI, had comparable treatment outcomes and tolerability following PP3M or PP1M treatment.

Registration: This study is registered at the EU clinical trial registry (EudraCT Number: 2011-004889-15) and ClinicalTrials.gov (identifier: NCT01515423).