Pain Therapeutics, Inc., a biopharmaceutical company, reported clinical results from the first of two phase III trials with Oxytrex, a novel oral opioid painkiller.

In this phase III study of 719 patients with severe chronic low-back pain, Oxytrex patients reported over 50 per cent less symptoms of physical dependence and withdrawal effects (p<0.01) after cessation of prolonged, high-dose opioid therapy compared to patients on oxycodone. Oxytrex patients reported equal pain relief to patients on oxycodone and about 20 per cent less overall opioid-related side-effects during treatment, including less somnolence (p<0.05), less pruritus (p<0.05) and 44 per cent less moderate-to-severe constipation (p<0.05).

"This is the first time a large, rigorous trial shows a meaningful improvement in physical dependence," said Lynn Webster, MD, lead investigator on this study, medical director of Lifetree Clinical Research & Pain Clinic in Salt Lake City, board certified physician in pain management and anesthesiology and a specialist in addiction medicine. "Physical dependence is a predictable effect of prolonged opioid therapy. Physicians or patients often associate physical dependence with addiction and avoid opioid painkillers altogether. Many recreational drug users who become hooked on opioids due to physical dependence find it inescapable to discontinue drug use. I think a new drug that provides pain relief yet curbs dependency stands to gain rapid acceptance in the medical community."

"Drug safety continues to dominate the public health agenda, especially with chronic drug treatments," said Remi Barbier, president and chief executive officer of Pain Therapeutics. "The oxycodone market is about $2 billion in size and represents over 10 million scripts per year. Will a broad swath of this market adopt a new drug that offers less physical dependence, less side-effects or lower dosing requirements? We believe so and that's why we're excited about our phase III results."

"We plan to discuss an NDA strategy for Oxytrex with the FDA in late 2005 after unblinding results of our second phase III trial," added Nadav Friedmann, PhD, MD, chief operating and medical officer at Pain Therapeutics.