Short-term efficacy and safety of lurasidone versus placebo in antipsychotic-naive versus previously treated adolescents with an acute exacerbation of schizophrenia

Background To evaluate the efficacy of short-term lurasidone in antipsychotic treatment-naive (TN) adolescents with schizophrenia versus those treated previously (TP) with antipsychotics. Methods Patients aged 13-17 with schizophrenia, and a Positive and Negative Symptom Scale (PANSS) score >= 70 and < 120, were randomized to 6 weeks of double-blind treatment with lurasidone (40 or 80 mg/day) or placebo. In a post-hoc, pooled-dose analysis, efficacy was evaluated for TN (criteria: never received antipsychotic treatment) versus TP at the time of the study. Treatment response criteria: >= 20% reduction in PANSS total score. Results Altogether, 57 TN and 269 TP patients enrolled in the 6-week DB study. Mean endpoint change in PANSS total score was significantly greater for lurasidone versus placebo in both the TN group (-25.0 vs. -14.4; p < 0.02; effect size = 0.75), and in the TP group (-17.3 vs. -10.0; p < 0.001; effect size = 0.45); and responder rates were higher for lurasidone versus placebo in both the TN group 84.6% versus 38.9%; number needed to treat [NNT] = 3 and in the TP group (60% vs. 42%; NNT = 6). Rates of treatment-emergent adverse events, and mean changes in body weight and metabolic parameters were similar for the TN and TP groups. Conclusions In a 6-week, placebo-controlled trial, lurasidone demonstrated significant efficacy in adolescents with schizophrenia regardless of previous antipsychotic therapy status; however, the effect size was notably larger in the TN patient group. In both the TN and TP groups, minimal effects were noted on weight, metabolic parameters, or prolactin.