FDA Advisors Recommend Approval of Subdermal Opioid-Dependence Drug Probuphine (Buprenorphine)
Final review set for April (Mar. 21)
The FDA’s Psychopharmacologic Drugs Advisory Committee (PDAC) has voted 10 to 4, with 1 abstention, for approval of Probuphine (Titan Pharmaceuticals), a subdermal implant formulation of buprenorphine, for the maintenance treatment of adults with opioid dependence.
A new drug application (NDA) for Probuphine was submitted in October 2012, and the drug was granted priority review designation, with a Prescription Drug User Fee Act (PDUFA) target action date of April 30, 2013.
The committee also voted 10 to 5 in favor of the drug’s effectiveness, and 12 to 2, with 1 abstention, in favor of its safety.
According to a report from Reuters, however, the committee was unconvinced that the marketing plan for Probuphine was safe enough, given the potential for abuse of such drugs. Moreover, some committee members said it was difficult to determine whether the drug’s intended dose would be sufficiently effective.
The FDA is not bound by the committee’s recommendation, but it will consider the committee’s guidance as it evaluates the Probuphine NDA.
According to recent estimates, 2.2 million people in the U.S. are opioid dependent. Approximately 80% of this population is addicted to prescription opioids, such as oxycodone, hydrocodone, methadone, hydromorphone, and codeine, and the other 20% is addicted to illicit opioids, such as heroin. The Drug Addiction Treatment Act of 2000 allowed medical office-based treatment of opioid dependence and greatly expanded patient access to medication-assisted therapies. As a result, an estimated 1.2 million people in the U.S. sought treatment for opioid dependence in 2011.
Probuphine is an investigational subdermal implant capable of delivering continuous blood levels of buprenorphine for 6 months following a single treatment. Buprenorphine, an approved agent for the treatment of opioid dependence, is currently available in the form of daily-dosed sublingual tablets and film formulations.
The efficacy and safety of Probuphine were evaluated in a placebo-controlled study that demonstrated statistically significant treatment benefits in 163 patients over a 24-week period. The results of this study were published in JAMA in October 2010. A confirmatory study in 287 patients, announced in July 2011, showed a statistically significant improvement in efficacy with Probuphine versus placebo, and non-inferiority with a currently marketed sublingual formulation of buprenorphine.