Early-onset schizophrenia is characterized by greater severity and more functional impairment than adult-onset schizophrenia. Few studies have prospectively evaluated short- or long-term antipsychotic efficacy in treatment-naïve (vs. previously treated) first-episode schizophrenia. The aim of this post-hoc analysis was to evaluate the long-term efficacy of lurasidone in antipsychotic-naïve adolescents with schizophrenia.

Patients aged 13-17 years with schizophrenia were randomized to 6 weeks of double-blind (DB), fixed-dose treatment with lurasidone (40 mg/day or 80 mg/day) or placebo. Six-week completers were eligible to enroll in an open-label (OL), flexible dose 2-year lurasidone treatment study. Efficacy over 104 weeks of OL treatment with lurasidone was evaluated for 2 patient groups based on treatment status prior to entering the initial DB study (treatment-naïve [TN] vs. treated previously [TP]). Treatment-naïve was defined as never having received antipsychotic treatment prior to randomization. Efficacy measures included the PANSS total score and the Clinical Global Impressions-Severity (CGI-S) score. Treatment response was defined as ≥20% reduction from baseline in PANSS total score.

A total of 50 TN and 221 TP patients completed the 6-week DB study and entered the extension study; and 30 (60.0%) TN and 126 (57.0%) TP patients completed 104 weeks. In the ITT population of the initial DB study, treatment with lurasidone (vs. placebo) yielded larger effects at DB endpoint on the PANSS total score in the TN group (-25.0 vs. -14.4; P<0.02; effect size [ES]=0.75) compared to the TP group (-17.3 vs. -10.0; P<0.001; ES=0.45); and in the CGI-S score in the TN group (-1.07 vs. -0.28; P=0.002; ES=0.97) compared to the TP group (-0.91 vs. -0.55; P=0.005; ES=0.38). During OL treatment with lurasidone, the magnitude of improvement from DB baseline continued to be somewhat larger in the PANSS total score for TN patients (n=38) vs. TP patients (151) at week 52 (-32.6 vs. -28.1) and week 104 (-33.6 vs. -29.2); and in the CGI-S score for TN vs. TP patients at week 52 (-2.1 vs. -1.5) and week 104 (-2.1 vs. -1.6). Responder rates during treatment with lurasidone were 72.0% (TN group) and 61.1% (TP group) at OL baseline (number-needed-to-treat [NNT]=10), 100% and 90.1% at week 52 [NNT=11], and 100% and 88.9% at week 104 [NNT=11]. During OL treatment, the most common adverse events for TN vs. TP patients were headache (26.0% vs. 23.5%), nasopharyngitis (24.0% vs. 5.4%), nausea (16.0% vs. 11.8%), and dizziness (16.0% vs. 4.1%).

In this post-hoc analysis of a 2-year OL extension study, antipsychotic-naïve adolescents with schizophrenia responded well to treatment with lurasidone at doses of 40 mg/day or 80 mg/day. TN patients achieved greater improvement than TP patients during acute treatment; and these greater treatment effects were largely maintained during 2 years of continued treatment with lurasidone.

Supported by funding from Sunovion Pharmaceuticals Inc