The company believes Oxytrex offers less physical dependence and withdrawal than oxycodone, the prescription painkiller widely used to treat persistent severe chronic pain.
This study is evaluating patients who depend on extremely high daily doses of oxycodone (greater than or equal to 120 mg per day) to treat severe chronic pain. Pain Therapeutics believes this sub-population of patients is prone to physical dependence and withdrawal.
The study's primary endpoint is defined as physical dependence/withdrawal scores in the treated arm compared to placebo. For ethical and other reasons, the study protocol allows an interim analysis.
In the second half of 2007, Pain Therapeutics plans to initiate a large study with Oxytrex in a broad patient population.
Oxytrex preferentially inhibits an excitatory effect of opioid receptors. This excitatory effect is believed to counteract pain relief and cause tolerance. Its inhibition enhances pain relief and minimizes opioid tolerance. The FDA has not yet evaluated the merits, safety or efficacy of Oxytrex.