Dr. Beebe and colleagues stated that subcutaneous implants deliver low levels of buprenorphine for up to 6 months. The current phase three study involving 287 opioid-dependent participants was conducted to see if it was as effective and safe as the oral form. Participants were initially induced with sublingual buprenorphine/naloxone and then randomized to receive buprenorphine implants, placebo or sublingual buprenorphine. All participants also underwent counselling.
During the first 24 weeks, patients who received buprenorphine, either sublingual or implant, achieved opioid-negative urine tests compared to those receiving placebo. Nearly two thirds of participants on the implants completed the study compared to just one-fourth of the placebo group. Treatment groups were also similar in terms of adverse effects with headache being the most common.
The process of implantation was well-tolerated. Dr. Beebe stated that the implant was inserted during a 10-minute office procedure using a local anesthetic. She also pointed out that the advantage of buprenorphine implant is the assurance of compliance, which is an issue among opiate dependents. This also eliminates the problem of misuse or diversion of the drug, which is possible with the oral forms of buprenorphine.
A new drug application for Probuphine is expected to be submitted to the US Food and Drug Administration (FDA) in September 2012. If the drug receives approval, it will be available on the market by the middle of 2013.