Relapse prevention study of paliperidone extended-release tablets in Chinese patients with schizophrenia

Objectives: The objective of this study was to evaluate the long-term efficacy, safety, and tolerability of paliperidone extended-release (pali ER), in Chinese patients with schizophrenia.

Methods: In this parallel-group, relapse prevention, phase-3 study (screening [14-day], pali ER open-label run-in [8-week] and stabilization [6-week] phases, and double-blind (DB) treatment [variable duration], and open-label extension phases [24-week]), 136/201 patients with schizophrenia were randomized (1:1) to pali ER (3-12 mg) or placebo during the DB phase.

Results: Final analysis showed that, out of 135 patients in ITT (DB) population, 71 (52.6%) had a relapse event, 45 (33.3%) were ongoing at the time the study was stopped, and 19 (14.1%) discontinued from the DB phase. Time to relapse (primary endpoint) favored pali ER (hazard ratio=5.23 [95% CI: 2.96, 9.25], p <0.0001). Rate of relapses (55/71 [77.5%] placebo; 16/64 [25%] pali ER) and secondary endpoints (change from baseline in Positive And Negative Syndrome Scale [PANSS] and Clinical Global Impression - Severity Scores) were significantly lower (p<0.001) in pali ER group vs placebo, in favor of pali ER. More psychiatric-related treatment-emergent adverse events (TEAEs) occurred in placebo- (21.1%) than pali ER group (10.9%). Most common (>3%) TEAEs in placebo group were insomnia and schizophrenia (8.5% each), while in pali ER group were aggression and akathisia (4.7% each), and schizophrenia, tremor, nausea, amenorrhea, and salivary hypersecretion (3.1% each). All serious TEAEs were psychiatric-related (schizophrenia, aggression, completed suicide, auditory hallucination, suicide attempt) and more frequent in placebo- (11.3%) versus pali ER group (3.1%). Death and tardive dyskinesia-related discontinuation (n=1 each) occurred in placebo group. Body weight increase from run-in baseline was greater in pali ER group (mean increase: 3.90 kg) versus placebo (mean increase: 2.05 kg).

Conclusions: This study confirms the findings from earlier pali ER global relapse-prevention studies and demonstrates that pali ER treatment (3-12 mg) is efficacious over the long-term and significantly delays relapse in Chinese patients with schizophrenia. No new safety signals were detected in this population.