Defining "Adequately Treated": A Post Hoc Analysis Examining Characteristics of Patients with Schizophrenia Successfully Transitioned from Once-Monthly Paliperidone Palmitate to Once-Every-3-Months Paliperidone Palmitate.

Purpose Paliperidone palmitate once every 3 months (PP3M) is indicated in adults with schizophrenia adequately treated with once-monthly paliperidone palmitate (PP1M) for at least 4 months, in whom the last two consecutive doses are the same. The decision of when to transition to PP3M is based on the patient's symptom status while receiving PP1M. Patients and methods In a double-blind relapse-prevention study (NCT01529515), patients who met Positive and Negative Syndrome Scale (PANSS) score stabilization criteria after 4 months of PP1M were eligible for transition to PP3M; those who continued to meet stabilization criteria after 12 weeks following an open-label PP3M dose were randomized to receive PP3M or placebo. We compared (post hoc) PANSS, Clinical Global Impression-Severity (CGI-S), and Personal and Social Performance (PSP) scores during the pre-randomization, open-label phase in patients in randomized versus non-randomized groups using analysis of variance or chi-square tests. Results Of 506 patients enrolled, 305 were randomized. After 4 months' PP1M treatment, PANSS and CGI-S scores were significantly lower and PSP scores significantly higher in randomized patients versus non-randomized patients (least squares means [95% CI]: 57.1 [55.7, 58.6] vs 62.2 [60.0, 64.3], 2.9 [2.8, 3.1] vs 3.3 [3.1, 3.4], and 67.0 [65.7, 68.3] vs 64.5 [62.6, 66.4], respectively); changes from baseline between groups differed significantly (all P ≤0.009). Conclusion Confirming adequate stabilization with PP1M prior to transitioning to PP3M is critical in maximizing treatment response; clinicians should consider transitioning patients to PP3M only if patients respond well to PP1M for at least 4 months and their last two consecutive doses are the same.