FDA advisory committees recommend approval of Indivior’s RBP-6000 to treat opioid use disorder

RBP-6000 is an investigational once-monthly injectable buprenorphine formulation in the ATRIGEL delivery system for the treatment of adults with moderate-to-severe OUD, as part of a complete treatment plan to include counseling and psychosocial support.

 "The Advisory Committees' favorable recommendation of RBP-6000 moves us one step closer to potentially bringing this once-monthly injectable buprenorphine treatment option to patients struggling with opioid use disorder," said Shaun Thaxter, Chief Executive Officer of Indivior.

"We are committed to pioneering new options for patients living with this chronic, yet treatable disease to help address the nation's growing opioid epidemic."

The FDA will consider the Advisory Committees' non-binding recommendation in its review of the New Drug Application for RBP-6000 that was submitted by Indivior on May 30, 2017. The FDA has set a Prescription Drug User Fee Act (PDUFA) target action date of November 30, 2017. 

RBP-6000 is an investigational buprenorphine sustained-release formulation using the ATRIGEL® delivery system, which consists of a polymeric solution of a biodegradable poly-(DL-lactide-co-glycolide) co-polymer dissolved in N-methyl pyrrolidone (NMP), a water-miscible biocompatible solvent.

After subcutaneous injection, NMP diffuses out of the polymer matrix and the polymer precipitates, trapping buprenorphine inside and forming an amorphous solid depot in situ. The depot releases buprenorphine over a one-month period by diffusion as the polymer biodegrades.

The Phase 3 study met its primary efficacy endpoint, with both RBP-6000 dosage regimens demonstrating abstinence rates that were significantly higher versus placebo (300 mg/300 mg: 41.3%; 300 mg/100 mg: 42.7%; placebo: 5.0%, p<0.0001). RBP-6000 was generally well tolerated and had a safety profile consistent with that of transmucosal buprenorphine except for injection site reactions.

Injection site reactions were not treatment-limiting and resulted in less than 1% of subjects discontinuing treatment. The most common (reported in ≥ 5% of subjects) adverse reactions reported in the active total group were constipation, headache, nausea, injection site pruritus, vomiting, increased hepatic enzyme, fatigue and injection site pain.

According to the DSM-51, opioid use disorder is characterized by signs and symptoms that reflect compulsive, prolonged self-administration of opioid substances that are used for no legitimate medical purpose or, if another medical condition is present that requires opioid treatment, they are used in doses greatly in excess of the amount needed for that medical condition.

Based on 2016 data from the most recent National Survey on Drug Use and Health report, 11.8 million Americans engaged in misuse of opioids in the last year. Approximately 2 million American adults (age 12+ years old) met criteria for opioid use disorder in the past year.

The same report suggested that 935,000 adults have used heroin in the past year and 471,000 used in the past month. There were approximately 625,000 adults who had a heroin use disorder in the past year2.

Indivior is a global specialty pharmaceutical company with a 20-year legacy of leadership in patient advocacy and health policy while providing education on evidence-based treatment models that have revolutionized modern addiction treatment.