Paliperidone Palmitate versus Risperidone Long-Acting Injection in Markedly-to-Severely Ill Schizophrenia Subjects

Objective: To examine onset of efficacy of two long-acting injectable atypical antipsychotics in markedly-to-severely ill schizophrenia subjects. Methods: This subgroup analysis included 292 subjects with baseline Clinical Global Im pressions-Severity scores of markedly ill or worse from a 13-week, randomized, double-dummy noninferiority study (NCT00589914). Subjects received either: 1) paliperidone palmitate (PP; 234 mg day 1 and 156 mg day 8 [corresponding to 150 and 100 milligram equivalents of paliperidone, respectively], both administered in deltoid muscle, followed by once-monthly flexible dosing in deltoid or gluteal muscle) and risperidone long-acting injection (RLAI)–matched placebo injections; or, 2) RLAI (25 mg, days 8 and 22; followed by biweekly flexible dosing) and PP-matched placebo injections. RLAI subjects received oral risperidone days 1–28; PP subjects received oral placebo. Because of RLAI’s release profile, data through day 22 correspond to oral risperidone. Assessments included Positive and Negative Syn drome Scale (PANSS) and adverse event (AE) reports. Paired t-tests assessed within-group changes. Results: LS mean (SE) PANSS total scores improved significantly (both p