Effects of acute paliperidone palmitate treatment in subjects with schizophrenia recently treated with oral risperidone

Objective

To examine efficacy and safety of acute treatment with paliperidone palmitate in subjects with schizophrenia whose disease remained symptomatic despite recent treatment with oral risperidone.

Methods

Post hoc analysis of a 13-week, double-blind, placebo-controlled study of subjects with symptomatic schizophrenia randomized to paliperidone palmitate 39, 156, or 234 mg (25, 100, or 150 mg equivalents of paliperidone) or placebo. Paliperidone palmitate subjects received a 234-mg day 1 dose, followed by their assigned dose on day 8 and monthly thereafter. Subjects treated with oral risperidone within 2 weeks before randomization regardless of duration were included. Assessments: PANSS, CGI-S, PSP scores; AEs. ANCOVA models with LOCF methodology evaluated treatment group differences.

Results

216 subjects received prior oral risperidone (paliperidone palmitate 39 mg, n = 53; 156 mg, n = 58; 234 mg, n = 48; placebo, n = 57). Median prior risperidone use was 22 days. Significant improvement was observed with paliperidone palmitate 156-mg or 234-mg versus placebo in least-squares mean (SE) score change at end point in PANSS total (156 mg, −15.8 3.0], p = 0.0001; 234 mg, −17.6 3.2], p = 0.0001), CGI-S (156 mg, −0.9 0.2], p = 0.0068; 234 mg, −1.1 0.2], p = 0.0003), and PSP (156 mg, 10.7 2.3], p = 0.0061; 234 mg, 12.9 2.4], p = 0.0009). Most common AEs (≥ 10%) in any paliperidone palmitate group were insomnia, anxiety, and headache.

Conclusions

In subjects with schizophrenia who recently received oral risperidone but who remained symptomatic, acute treatment with monthly doses of 156-mg and 234-mg paliperidone palmitate significantly improved clinical symptoms, global illness ratings, and functioning compared with placebo, with no unexpected safety findings.