BY OUR PHARMA CORRESPONDENT
13 September,2005: In the phase 3 study, the safety and efficacy of abuse-resistant oxycodone (Remoxy) was compared against placebo in osteoarthritic patients with moderate-to-severe chronic pain. The study design was randomized, double-blinded and enrolled 209 patients in over 20 U.S. clinical sites. Patients were treated with Remoxy 20 mg or matching placebo twice daily over a 4-week study period. Patient demographics and baseline pain scores were similar in both arms, reported Pain Therapeutics, Inc.
The primary objective of this study was to evaluate pain relief. Results demonstrated a statistically significant difference (p<0.05) between Remoxy and placebo in the study's primary endpoint: percent decrease in pain scores from baseline to final study visit, measured with a standard Likert Pain Scale.
The secondary objective of this study was to evaluate patients' quality of life. Results demonstrated statistically significant differences (p<0.05) between Remoxy and placebo in each component of the WOMACTM Osteoarthritis Index, in physical function measured by a standard SF-12(R) Health Survey and in patients' self-reported Quality of Analgesia.
The report mentioned no drug-related safety issues. However, it maintained that, as expected, opioid-related adverse events were higher in the Remoxy arm compared to the placebo arm. Adverse events typically associated with chronic opioid use include nausea/vomiting, dizziness, pruritus (itching), and somnolence/sedation. Also as expected, the patient drop-out rate was higher in the Remoxy arm (35%) compared to the placebo arm (24%). Patients in the Remoxy arm dropped mainly due to opioid-related adverse events. Patients in the placebo arm dropped mainly due to lack of efficacy.
The company plans to conduct a large, pivotal phase III registration study that can support a New Drug Application under an FDA filing strategy known as 505(b)(2). The company expects to initiate this study by year-end 2005.
Oxycodone is a strong opioid painkiller and is the active drug ingredient in Remoxy. Oxycodone is also the active drug ingredient in Oxycontin, a brand name drug with sales of nearly $2 billion in 2004. Long-acting versions of oxycodone are widely used to treat moderate-to-severe chronic pain. However, drug abusers can easily extract oxycodone from Oxycontin tablets (and all other marketed versions of long-acting oxycodone) in order to induce a quick and powerful euphoric high. Abusers of long-acting oxycodone risk respiratory depression, which can be fatal, and opioid addiction. According to government data, oxycodone abuse resulted in over 20,000 visits to emergency rooms and hundreds of deaths in 2002.
The FDA has not yet evaluated the merits, safety or efficacy of Remoxy. Remoxy has a sticky, high-viscosity mass that resists injection or snorting. Published data show that freezing, crushing or submerging Remoxy in high-proof alcohol for hours at a time releases just a fraction of oxycodone compared to Oxycontin at time points when abusers presumably expect to get high, a Pain Therapeutics release said.
Pain Therapeutics Inc is a biopharmaceutical company. It develops candidates for severe chronic pain, such as low-back pain or pain due to osteoarthritis or irritable bowel syndrome. The company has three drug candidates in phase 3 clinical development: Oxytrex, Remoxy and PTI-901.
BY OUR PHARMA CORRESPONDENT