Efficacy and Safety of Paliperidone Palmitate 6-Month versus Paliperidone Palmitate 3-Month Long-Acting Injectable in European Patients with Schizophrenia: A Post Hoc Analysis of a Global Phase-3 Double-Blind Randomized Non-Inferiority Study

Cesar Giron‐Hernandez,1 Joong Hee Han,2 Roberta Alberio,3 Arun Singh,2 Maria Paz García-Portilla,4 Maurizio Pompili,5 R Karl Knight,2 Ute Richarz,6 Srihari Gopal,2,7 José Antunes8 1EMEA Medical Affairs, Janssen-Cilag, Issy-les-Moulineaux, France; 2Janssen Research & Development, LLC, Titusville, NJ, USA; 3Medical Affairs, Janssen-Cilag, Milan, Italy; 4Department of Psychiatry, Universidad de Oviedo, Instituto Sanitario Del Principado de Asturias (ISPA) and CIBERSAM, Oviedo, Spain; 5Department of Neurosciences, Mental Health, and Sensory Organs, Sant’Andrea Hospital, Sapienza University of Rome, Rome, Italy; 6Janssen Global Services LLC, Cilag Int., Zug, Switzerland; 7Regeneron Pharmaceuticals, Tarrytown, NY, USA; 8EMEA Medical Affairs, Janssen-Cilag, Porto Salvo, PortugalCorrespondence: José Antunes, EMEA Medical Affairs, Janssen-Cilag, Porto Salvo, Portugal, Email jantune1@its.jnj.comPurpose: To examine efficacy and safety of paliperidone palmitate (PP) 6-month (PP6M) vs PP3-month (PP3M) long acting injectable (LAI) in patients with schizophrenia from European sites previously stabilized on PP3M or PP1-month (PP1M).Methods: This post-hoc subgroup analysis used data from a global phase-3 double-blind (DB) randomized non-inferiority study (NCT03345342). Patients were randomized (2:1, respectively) to receive dorsogluteal injections of PP6M (700 mg eq. or 1000 mg eq.) or PP3M (350 mg eq. or 525 mg eq.) in the 12-month DB phase. Primary endpoint was time-to-relapse during the DB phase, using a Kaplan–Meier cumulative survival estimate (non-inferiority margin 95% CI lower bound larger than prespecified as − 10%). Treatment emergent adverse events (TEAEs), physical examinations, and laboratory tests were also evaluated.Results: A total of 384 patients who entered the DB phase were included in European sites (PP6M, n = 260; PP3M, n = 124) with a mean age similar in both groups (mean age [SD] years: PP6M, 40.0 [11.39]; PP3M, 38.8 [10.41]). Baseline characteristics were similar across both groups. The number of patients who experienced a relapse during DB phase were PP6M: 18 (6.9%) vs PP3M: 3 (2.4%) with percentage relapse-free difference of − 4.9% (95% CI: − 9.2%, − 0.5%), thus achieving non-inferiority criteria. Secondary efficacy endpoints indicated comparable improvements. Incidence of TEAEs was similar between PP6M (58.8%) and PP3M (54.8%) groups. Nasopharyngitis, headache, increased weight, and injection-site pain were the most common TEAEs.Conclusion: The efficacy of PP6M was non-inferior to that of PP3M in preventing relapse in the European subgroup previously treated with PP1M or PP3M, which was consistent with the global study. No new safety signals were identified.Keywords: Europe, long-acting injectable, paliperidone palmitate 6-month, relapse-free, schizophrenia