Opioid analgesics play an important role in the management of both acute and chronic pain conditions. Opioids exert their effects by binding to opioid receptors. While some of the effects, such as analgesia are desirable, others such as sedation, nausea, cognitive impairment and constipation, can be troublesome. Since chronic pain necessitates the use of long term treatment, such adverse events can impact quality of life and impede adherence. Additionally, use of long-term therapy can lead to concerns regarding drug abuse, addiction and dependency.
Buprenorphine is a partial mu-opioid receptor agonist and a kappa antagonist, making it unique compared to full mu-opioid agonists such as morphine. It is a potent analgesic with a relatively long duration of action. Buprenorphine is a Schedule III controlled substance meaning that it has lower abuse potential than Schedule II drugs.
In January 2012, BDSI signed a worldwide license and development agreement with Endo Pharmaceuticals for the exclusive rights to develop and commercialize BEMA® Buprenorphine for the treatment of chronic pain.
BEMA® Buprenorphine is currently in Phase 3 clinical development for the treatment of moderate to severe chronic pain. The Phase 3 program for BEMA® Buprenorphine consists of two efficacy studies. Both studies are double-blind, randomized, placebo-controlled, enriched-enrollment studies in patients with chronic lower back pain. BUP-307 is being conducted in opioid experienced subjects, and BUP-308 was conducted in subjects naïve to opioid therapy.
In January, BDSI and Endo announced positive top-line results from the pivotal Phase 3 efficacy study in opioid naïve subjects (BUP-308). The trial successfully met its primary efficacy endpoint demonstrating significantly (p<0.005) improved chronic pain relief compared to placebo. Results from the Phase 3 pivotal efficacy trial in opioid experienced patients are expected mid year. Additional information can be found at www.clinicaltrials.gov.