FDA Advisors Back Two Opioid Use Disorder Therapies

Braeburn, Indivior recommended by large margins

FDA advisory committees voted in a joint session to endorse two proposed products for the treatment of opioid problems: CAM2038 (Braeburn Pharmaceuticals, Inc.) and RBP-6000 (Indivior PLC). The agency is not obliged to follow the recommendations of its advisory committees, but it often does so.

Braeburn said the vote by the Psychopharmacologic Drugs Advisory Committee and Drug Safety and Risk Management Advisory Committee was 17 to 3 recommending approval of CAM2038, an investigational buprenorphine weekly and monthly depot injection for the treatment of adults with opioid use disorder (OUD). The FDA asked the committees to vote on recommended approval of all, some, or none of the proposed doses of CAM2038. The committees voted 17 in favor of approval of some of the proposed doses and three in favor of none of the proposed doses of CAM2038.

The committees’ recommendation was based on a review of results from a clinical trial program that included seven phase 1, 2, and 3 clinical trials in patients with OUD, including a pivotal phase 3 efficacy and a long-term safety study. CAM2038 was accepted under priority review designation by the FDA in September 2017 and previously granted fast track designation. The FDA has set a Prescription Drug User Fee Act (PDUFA) target date of January 19, 2018.

CAM2038 is an investigational buprenorphine weekly and monthly depot subcutaneous injection for the treatment of OUD as a part of a comprehensive treatment plan to include counseling and psychosocial support. The product is designed for flexible and individualized treatment from initiation and stabilization to longer-term maintenance therapy, providing sustained buprenorphine release in once-weekly and once-monthly formulations.

Indivior PLC said the two committees voted 18 to 1 to recommend approval of RBP-6000 for the treatment of OUD. 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 FDA has set a Prescription Drug User Fee Act (PDUFA) target action date of November 30, 2017, for Indivior’s application.

RBP-6000 is an investigational buprenorphine sustained-release formulation. The Atrigel delivery system 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 RBP-6000 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.

Sources: Braeburn Pharmaceuticals, Inc.; November 1, 2017; Indivior; October 31, 2017.