Efficacy and Safety of Paliperidone Palmitate 6-Month Formulation: A 3-Year Analysis in Adults With Schizophrenia

This work was sponsored by Janssen Scientific Affairs, LLC This analysis assessed the efficacy and safety of paliperidone palmitate 6-month (PP6M) for up to 3 years by following adult patients from a double-blind (DB) randomized controlled trial (NCT03345342) through a 2-year, single-arm, open-label extension (OLE) study (NCT04072575). In the DB study, patients were initially randomly assigned to moderate or high doses of paliperidone palmitate 3-month (PP3M) or PP6M for 1 year. Patients without relapse in the DB study could continue PP6M in the OLE study. Efficacy endpoints included assessment of relapse and change from baseline in Positive and Negative Syndrome Scale (PANSS) total and subscale scores, Clinical Global Impression-Severity (CGI-S) and Personal Social Performance (PSP) scales. Safety was assessed via treatment-emergent adverse events (TEAEs), injection site evaluation, and laboratory tests. A total of 121 patients were included in this 3-year intention-to-treat analysis (demographic and baseline [DB] characteristics: mean age, 38.6 years; male, 68.6%; mean duration of illness, 11.0 years). At study entry, 83.5% of patients were taking an oral antipsychotic and 16.5% were taking a long-acting injectable antipsychotic. The relapse rate was 4.1% (5/121 patients) and the reasons for relapse were psychiatric hospitalization (n=2), suicidal or homicidal ideation (n=2), and deliberate self-injury (n=1). Clinical improvements observed in PANSS, CGI-S, and PSP scores during the DB phase were maintained throughout the OLE study. No new safety or tolerability concerns were identified, with 80.2% of patients reporting ≥1 TEAE. These results support the long-term efficacy and safety of PP6M for up to 3 years in adults with schizophrenia.