No new safety signals or unexpected safety findings were seen in this long-term safety study. The profile of observed adverse events (AEs) was similar to that reported for risperidone and in previous short-term studies with RBP-7000.
Measures of clinical efficacy in the RB-US-13-0005 trial demonstrated that patients remained stable or improved across study visits over 12-months as evidenced by decreases in mean Positive and Negative Syndrome Scale (PANSS) total and Clinical Global Impression-Severity of Illness (CGI-S) scores.
Health outcome measures showed no deleterious effect of treatment, high medication satisfaction and preference to treatment, and good long-term prognosis for stability. This is the first demonstration of safety and durability of effect for a once-monthly injectable form of risperidone administered subcutaneously (SC) in a long-term clinical trial.
Indivior chief scientific officer Christian Heidbreder said: “Schizophrenia is a chronic, severe and disabling brain disorder that affects an estimated 23 million people worldwide.
“With these positive preliminary findings, we are expeditiously moving toward filing a New Drug Application, which we target in Q4-2017, to bring RBP-7000 to the patients and physicians who need new treatment options for this serious disease.”
The Phase 3, open-label study was designed to evaluate the long-term safety and tolerability of RBP-7000 in patients with schizophrenia. RBP-7000 was administered at a dose of 120 mg via subcutaneous injections once monthly for 12 months, using the Atrigel delivery system.
The study was performed at approximately 50 sites in the U.S. About 500 patients were enrolled into the trial to ensure 300 patients achieved 6 months and 100 patients achieved 1 year of treatment with RBP-7000.
The following patients were assessed for participation in this study: rollover patients who completed the Phase 3 double-blind, placebo-controlled, efficacy study of RBP-7000 (Study RB-US-09-0010) conducted in patients with acute schizophrenia and had completed 56 days of double-blind treatment, and patients newly diagnosed with schizophrenia with a PANSS score of ≤70.
The primary objective of this study was to assess the long-term safety and tolerability of RBP-7000 in patients with schizophrenia. The secondary objectives of this study were to continue collecting clinical efficacy measures to assess the durability of effect of RBP-7000 in subjects with schizophrenia using the PANSS and CGI-S scales.
Tertiary objectives of this study were to continue collecting the health economics and patient-reported outcome data that were collected in the Phase 3 double-blind study and additionally to collect data on the SF-36 Physical and Mental summary scores and healthcare utilization.
Over the course of the 12-month treatment with RBP-7000, those patients who had been stable at enrollment remained clinically stable. Those patients and those who had been acutely ill in the previous 8 weeks and treated with 2 injections of RBP-7000 prior to “roll-over” enrollment in the long-term trial showed continuous improvement, both as determined by the PANSS and CGI-S scores.
In addition, health outcome measures showed no deleterious (harmful or worsening) effect of RBP-7000 treatment (e.g., healthcare utilization, well-being, and quality of life) with high medication satisfaction and preference to treatment. Also, based on SF-36 Physical and Mental summary scores from this trial, patients treated with RBP-7000 have good long-term prognosis for stability in schizophrenia.