Pain Therapeutics Inc., a biopharmaceutical company, achieved results of a 775-patient Phase III trial with Oxytrex, an investigational drug candidate. The pre-defined primary endpoint was reduction in physical dependency, as measured by SOWS.

The company expected Oxytrex to reduce physical dependency by 25% or more. In this trial, Oxytrex reduced physical dependency by 28% compared to an equivalent dose of oxycodone but this result did not reach statistical significance due to high drop-out rates in all study arms, states a company release.

Nadav Friedmann, chief operating and medical officer at Pain Therapeutics, stated, "This is the second of two large trials designed to examine opioid-related physical dependency. We see a consistent and positive clinical response in the two trials. We are highly encouraged by the promise of the science however; in today's trial we believe the signal was lost in the noise. There are ways to design clinical trials that overcome the statistical limitations imposed by very high drop-out rates. We expect to discuss these methodologies with the FDA in early 2006."

Pain Therapeutics anticipated that up to 40% of patients would drop-out before completing the study's three-month treatment period. Actual drop-out rates were 48% to 60% in the drug arms and 37% in the placebo arm. The number of patients completing the study was lower than expected and, given the statistical rigor of the study design, statistical significance was not reached in the primary endpoint.

"We believe the weight of all evidence, including prior clinical and non-clinical data, continues to favour Oxytrex over oxycodone," said Remi Barbier, president and CEO of Pain Therapeutics. "We remain steadfast to the Oxytrex program and its ability to reduce physical dependency."

Remi Barbier added, "We also note that today's clinical news does not impede the closing of our recently announced strategic alliance with King Pharmaceuticals, Inc. We expect to enter 2006 with over $200 million of cash, thanks to proceeds from this alliance. Preliminarily, we believe our net cash burn rate may be under $15 million in 2006, subject to final budget approvals."

Pain Therapeutics is an emerging biopharmaceutical company that develops novel drugs. The company's investigational drug candidates target different types of chronic pain, such as low-back pain, pain due to osteoarthritis or irritable bowel syndrome.