RBP-7000 for the Treatment of Schizophrenia: Efficacy and Safety Results From Two Phase III Trials

Introduction: RBP-7000 is a subcutaneously administered, once-monthly, extended-release depot formulation of risperidone designed to achieve therapeutic concentrations without supplemental oral dosing.

Methods: In an 8-week double-blind placebo-controlled (DBPC) study (NCT02109562), patients with acute schizophrenia were randomized to placebo or RBP-7000 90mg or 120mg. Patients completing the DBPC trial or de novo patients could enter a 1-year open-label extension (OLE) study (NCT02203838) of RBP-7000 120mg. Efficacy measures included Positive and Negative Syndrome Scale (PANSS) total score change from baseline and percentage of participants achieving PANSS response (≥20% improvement). Safety assessments included treatment-emergent adverse events, EPS scales, and suicidality.

Results: Of 354 randomized participants in the DBPC study, 92 completers enrolled in the OLE with 408 stable de novo participants. In the DBPC study, significant (P<0.01) improvement in PANSS total score change from baseline was observed in participants receiving RBP-7000 90mg (LSMD:-6.5±2.2) or 120mg (LSMD:-10.2±2.2) compared with placebo at Day 57, and a higher percentage of participants achieved PANSS response with RBP-7000 90mg (51.1%) and 120mg (56.5%,) than with placebo (34.5%). In the OLE, PANSS total score indicated improvement from baseline in rollover participants (RBP-7000 90mg:-12.5±15.5; 120mg:-10.9±13.2; placebo:-20.2±15.6) and minimal change in de novo participants (-0.4±8.7); 44.4% of rollover participants and 7.6% of de novo participants were responders. No unexpected safety signals or clinically meaningful changes in safety assessments were observed in either study.

Conclusion: RBP-7000 significantly reduced schizophrenia symptoms, with continued improvement in rollover participants. The safety profile of RBP-7000 following 12 monthly injections was consistent with that of oral risperidone.