An Open-Label Study to Assess Monthly Risperidone Injections (180 mg) Following Switch from Daily Oral Risperidone (6 mg) in Stable Schizophrenic Patients

Long-acting injectable antipsychotics have shown benefits over oral medications with reduced hospitalization rates and improved health-related quality of life. RBP-7000 (PERSERIS^®) is a monthly risperidone formulation (90 or 120 mg) for the treatment of schizophrenia administered by subcutaneous abdominal injection. The objective of this study was to assess a higher dose of 180 mg RBP-7000 and an alternate injection site.

Following stabilization on 6 mg/day (3 mg twice daily) oral risperidone, clinically stable schizophrenic participants received 3 monthly doses of 180 mg RBP-7000 in the abdomen followed by a fourth monthly dose of 180 mg RBP-7000 in the upper arm (each dose administered as two 90-mg injections). The primary endpoint was the steady-state average plasma concentration (C_avg(ss)) of risperidone and total active moiety after oral and RBP-7000 administration. Secondary endpoints included measures of clinical efficacy (Positive and Negative Syndrome Scale, Clinical Global Impression Scale for Severity of Illness), safety, and local injection-site tolerability to assess the switch from oral risperidone and compare injection sites.

In all, 23 participants received at least one dose of RBP-7000, 16 received all four doses, and 15 completed the study. Monthly doses of 180 mg RBP-7000 provided similar C_avg(ss) of total active moiety compared with 6 mg/day oral risperidone. The pharmacokinetics of RBP-7000 were similar after injection in the abdomen versus upper arm. Clinical efficacy measures remained stable throughout the study. All RBP-7000 injections were well tolerated with no unexpected safety findings.

The results support the use of 180 mg RBP-7000 in schizophrenic patients stable on 6 mg/day oral risperidone and a second injection site in the upper arm.

ClinicalTrials.gov identifier: NCT03978832.