A double-blind study of paliperidone palmitate and risperidone long-acting injectable in adults with schizophrenia

This 13-week double-blind study was designed to assess noninferiority of the recently approved (in the U.S.) injectable atypical antipsychotic paliperidone palmitate (PP) versus risperidone long-acting injectable (RIS-LAI) in adult patients with schizophrenia. Patients (N = 1220) were randomized (1:1) to either a) PP: deltoid injections on day 1 (150 mg eq.), day 8 (100 mg eq.), and once-monthly flexible dosing as deltoid or gluteal injections on day 36 (50 mg eq. or 100 mg eq.) and day 64 (50 mg eq. or 100 mg eq. or 150 mg eq.) or b) RIS-LAI: gluteal injections days 8 and 22 (25 mg), days 36, 50 (25 or 37.5 mg) and days 64, 78 (25, 37.5 or 50 mg). RIS-LAI-treated patients received oral supplementation with RIS 1-6 mg/day (days 1 to 28), and PP-treated patients received oral placebo. The safety analysis set (n = 1214) included 58% men, 78% white, with mean (SD) baseline PANSS total score: PP, 84.1 (12.09); and RIS-LAI, 83.6 (11.28). Mean (SD) change from baseline to endpoint in PANSS total score decreased similarly in both groups; PP (−18.6 [15.45]) and RIS-LAI (−17.9 [14.24]). PP treatment was noninferior to RIS-LAI (point estimate [95% CI]: 0.4 [−1.62;2.38], per-protocol analysis set [primary analysis]). The tolerability and safety of PP was generally similar to RIS-LAI with no new safety or tolerability findings.

Research highlights►Paliperidone palmitate was demonstrated to be noninferior to risperidone long-acting injectable in treatment of schizophrenia using the approved initiation dose strategy. ►Paliperidone palmitate was generally safe and tolerable. ►Pharmacokinetic results were similar between both treatments.