An advisory committee to the Food and Drug Administration has recommended approval of an implantable version of buprenorphine, an opioid addiction treatment drug widely known as Suboxone.
The FDA’s Psychopharmacologic Drugs Advisory Committee voted 10 to 4 in favor of the implant, with one abstention. The implant was developed by Titan Pharmaceuticals (OTCBB:TTNP) and would be sold under the brand name Probuphine.
The advisory committee also voted in favor of the effectiveness (10 to 5) and safety (12 to 2) of Probuphine. However, a majority of the committee members abstained on the vote pertaining to the drug’s Risk Evaluation and Mitigation Strategy (REMS) program, which is still under review at the FDA.
The agency usually follows the guidance of its advisory committees. A final decision on Probuphine is expected by April 30th.
“We are pleased the Committee recognized the favorable benefit-risk profile of Probuphine and voted in strong favor of its approval,” said Kate Glassman-Beebe, PhD, executive vice president and chief development officer of Titan. “We look forward to working with the FDA to complete its review of Probuphine and remain committed to addressing the growing unmet needs in managing patients with opioid dependence.”
The Probuphine implant gives patients a steady dose of buprenorphine for up to 6 months via four to five rods, each about the size of a matchstick, that are implanted under the skin in the upper arm. Currently, buprenorphine is only available in tablet and film formulations (Suboxone).
FDA staff have questioned the effectiveness of the implant and suggested the dose was too low, noting in clinical trials that about half of the patients treated with Probuphine required additional oral doses of Suboxone to treat their opioid craving and withdrawal symptoms. The staff review said Probuphine does limit drug use but, “overall the experience was not what one might hope for.”
However, those same studies also found that patients treated with Probuphine had fewer urine samples that tested positive for opioids. And in one study, nearly two-thirds of the patients completed 24 weeks of treatment without reporting withdrawal symptoms.
Titan has an exclusive license agreement with Braeburn Pharmaceuticals to the commercialization rights for Probuphine in the United States and Canada. Titan received an upfront payment of $15.75 million from Braeburn and will receive up to $50 million if Probuphine is approved by the FDA. In addition, Titan will also receive royalties on net sales of Probuphine and additional payments if the implant is approved for other uses, such as treating chronic pain.
Titan and other drug makers are anxious to enter the lucrative market for Suboxone. Sales of Suboxone tablets and film reached $1.3 billion in the U.S. in 2011 and are growing by about 10% annually. Last month the FDA approved generic tablet versions of Suboxone, effectively ending a decade-long monopoly that a British Pharmaceutical company, Reckitt Benckiser, had on sales of the drug.
Buprenophine (Suboxone) is an opioid that was first approved as a treatment for opioid addiction in the U.S. in 2002. Over three million Americans with opioid dependence have been treated with Suboxone. Although praised by addiction experts as a tool to wean addicts off opioids, some are fearful the drug is being overprescribed and misused, leading to even more addiction.
Titan believes Probuphine is safer and less likely to be abused then oral forms of buprenorphine because the implant is placed by a physician and is not readily accessible to patients, thereby reducing the potential for overdose, abuse and diversion.