West Coast Editor

Reporting success in the second of three Phase III studies with separate drugs, Pain Therapeutics Inc. said Remoxy, its abuse-resistant form of long-acting oxycodone, hit its primary endpoint of decrease in pain scores from baseline to final study visit.

"In this business, all it takes is one drug to really succeed, and we feel we comfortably have two viable drugs," said Remi Barbier, president and CEO of South San Francisco-based PTI. "At the end of this year, we'll see if we have a third."

The company's stock (NASDAQ:PTIE) closed Friday at $6.71, up 18 cents, as Wall Street "continues to miss" the importance of the findings, Barbier told BioWorld Today.

With Remoxy, "in 2004, we had anti-abuse data, and now we have efficacy data," he pointed out. Specifically in this study, the safety and efficacy of Remoxy was compared to placebo in osteoarthritic patients with moderate to severe chronic pain.

Randomized and double blinded, the trial enrolled 209 patients at more than 20 U.S. clinical sites. Patients were treated with 20 mg of Remoxy or matching placebo twice daily over the 4-week study period. Patient demographics and baseline pain scores were similar in both arms.

The study showed a statistically significant difference (p<0.05) between Remoxy and placebo in the study's primary endpoint as measured with a standard Likert Pain Scale.

Quality of life was the secondary endpoint, and data turned up statistically significant differences (p<0.05) between Remoxy and placebo in each part of the Western Ontario and McMaster Universities Osteoarthritis Index, in physical function measured by a standard SF-12 Health Survey and in patients' self-reported Quality of Analgesia.

No drug-related safety issues were noted although, as expected, opioid-related adverse events were higher in the Remoxy arm compared to the placebo arm. Such events included nausea/vomiting, dizziness, itching and somnolence/sedation.

Also as expected, the drop-out rate was higher in the Remoxy arm (35 percent) compared to the placebo arm (24 percent). Patients in the Remoxy arm dropped out mainly due to opioid-related adverse events, and those in the placebo arm quit mainly due to lack of efficacy.

PTI next plans a large, pivotal Phase III registration study that can support a new drug application under Section 505(b)(2). The company expects to start the study by the end of this year.

"It's going to be larger and longer," Barbier said. "I can't be specific because we're still negotiating with the FDA, but you can think in terms of a few hundred patients and three months."

Trials with compounds such as those tested by PTI are "never easy and never fast enough, but they're relatively affordable," he said.

Two other pain products also are at the Phase III stage. In March, the company reported data from the first of two studies with the opioid painkiller Oxytrex, proving that patients experienced the same pain relief but reported less physical dependence and fewer side effects than those taking oxycodone. (See BioWorld Today, March 25, 2005.)

A second study with Oxytrex is ongoing and will report data "between Thanksgiving and the end of the year," Barbier said. Results from a study of the company's third compound, PTI-901, in irritable bowel syndrome also are expected at the end of his year.

"We're going to end the year with a bang - or not," Barbier said.