SOUTH SAN FRANCISCO, Calif., Sept. 22 /PRNewswire-FirstCall/ -- Titan Pharmaceuticals, Inc. (OTC Bulletin Board: TTNP) today announced that patient enrollment is now complete in the confirmatory, Phase 3 clinical study of Probuphine for the treatment of opioid addiction. This placebo and active controlled Phase 3 study is being conducted at 20 sites in the United States and the results are expected in the second quarter of 2011, about three months ahead of the original schedule. This study is part of a registration-directed program intended to obtain marketing approval of Probuphine for the treatment of opioid addiction in the United States and Europe.
"We are very encouraged by the excellent response to recruitment for this trial. Thanks to the ongoing dedication of the Probuphine Consortium of clinical investigators and their staff, we expect to report the results of this important trial significantly ahead of schedule, in the second quarter of next year," said Dr. Katherine L. Beebe, Senior Vice President, Clinical Development and Medical Affairs and Principal Investigator of the study.
This study is partially supported by a two-year $7.6 million, Research and Research Infrastructure Grand Opportunities grant through the American Reinvestment and Recovery Act of 2009 (ARRA), and the second year allocation of approximately $2 million has recently been approved by the National Institutes of Health (NIH). The grant is administered by the National Institute on Drug Abuse (NIDA).
Initial safety and effectiveness of treatment for opioid addiction with Probuphine has been demonstrated in a series of clinical studies. Probuphine also has the potential to reduce limitations currently associated with daily oral buprenorphine therapy, including poor compliance, withdrawal and craving symptoms associated with variable blood levels and diversion and non-medical use of the drug. Results of the Probuphine development program to date will be presented during a symposium titled "Buprenorphine Implant for the Long-Term Treatment of Opioid Dependence," on October 6, 2010 in Milan, Italy at the 2010 International Society of Addiction Medicine (ISAM) conference. The 90-minute symposium is co-chaired by Dr. Beebe of Titan and Dr. Ivan Montoya of NIDA, Division of Pharmacotherapies and Medical Consequences of Drug Abuse (DPMCDA), and will cover all aspects of the Probuphine development program from early non-clinical studies to pharmacokinetic and clinical studies demonstrating the safety and effectiveness of Probuphine. Further information about the scientific program may be found on the ISAM website at http://www.isam2010.medicina.unimib.it/scientific_program/day6/
The World Health Organization estimates that 2.8 million individuals in the U.S. and Europe are addicted to illicit opiates such as heroin, and more than 2.0 million individuals in the U.S. alone are addicted to prescription opioid medications. It is estimated that about twenty percent of this population are currently receiving pharmacological treatment.
Probuphine is designed to deliver six months of continuous round-the-clock, long-term therapeutic levels of the drug buprenorphine following a single subcutaneous treatment. Buprenorphine, an approved agent for the treatment of opioid addiction, is currently available mainly in the form of a sublingual tablet formulation. The safety and effectiveness of treatment with Probuphine has been initially established in the three Phase 3 studies conducted to date, specifically, a 163 patient placebo controlled study which demonstrated clinically meaningful and statistically significant treatment with Probuphine over a 24 week period, an open label 24 week retreatment study in 62 patients who had successfully completed six months of treatment in the controlled study, and a relative bioavailability study in 9 patients treated with Suboxone® and then switched to Probuphine treatment for 60 days.
Probuphine was developed using ProNeura, Titan's continuous drug delivery system that consists of a small, solid rod made from a mixture of ethylene-vinyl acetate (EVA) and a drug substance. The resulting product is a solid matrix that is placed subcutaneously, normally in the upper arm in a simple office procedure, and is removed in a similar manner at the end of the treatment period. The drug substance is released slowly, at continuous levels, through the process of diffusion. This results in a constant rate of release similar to intravenous administration.