Pain Therapeutics, Inc. and King Pharmaceuticals, Inc. said their chronic pain treatment candidate Remoxy showed positive results in a phase III study. The study met the primary endpoint that was prospectively defined by the US Food and Drug Administration (FDA) during the Special Protocol Assessment process.

Remoxy, an investigational drug, is an abuse-deterrent version of long-acting oxycodone, a powerful painkiller available only by prescription. Remoxy is intended to meet the needs of physicians or pharmacists who appropriately prescribe or dispense long-acting oxycodone and who seek to minimize the risks of abuse, misuse or diversion.

The FDA has agreed in writing that a single phase III pivotal study is needed to support the regulatory approval of Remoxy. As a result, Pain Therapeutics expects to file a New Drug Application for Remoxy in Q2 2008. If approved, Remoxy will be the first oxycodone on the market that is specifically designed to deter common methods of abuse.

"Preserving the safety and integrity of prescription drugs is always the right choice," said Remi Barbier, chairman, president and chief executive officer, Pain Therapeutic. "We pioneered the development of abuse-deterrent opioids to raise the bar on drug safety to a new level. We believe prescription drugs that minimize the risks of abuse, misuse or diversion can deliver peace of mind to physicians, pharmacists and patients in pain."

Brian A. Markison, chairman, president and CEO, King Pharmaceuticals, stated, "Opioid analgesics play a very important role in the effective management of moderate-to-severe pain. However, abuse and misuse of these medicines represents a major area of concern among healthcare professionals and patients."

"Data show that over 12 million Americans used prescription pain relievers for non-medical use in 2006, including approximately four percent of high school seniors. We are addressing this alarming public health issue by developing pain medicines that incorporate safe and appropriate means to discourage abuse and misuse. The successful completion of the pivotal phase III study for Remoxy is particularly exciting, as it is the first of several abuse-deterrent opioid pain products which we plan to develop that are formulated to deter the inappropriate use of these drugs," Markison added.

This pivotal phase III randomised, double-blinded, placebo-controlled, multi-centre study was designed to evaluate the analgesic efficacy of twice-daily Remoxy versus placebo over a 12- week treatment period. Over 400 patients with osteoarthritis participated in this pivotal study. The study randomised 412 male and female patients. All patients were diagnosed with osteoarthritis of the knee or hip, as evidenced by x-ray and clinical criteria of the American College of Rheumatology. Additionally, all patients had pain intensity scores corresponding to moderate-to-severe pain.

Following informed consent, wash-out and dose titration, patients were randomised (1:1) into a double-blinded treatment period (12 weeks). During treatment, patients received twice-daily Remoxy or matching placebo. The total drug dose per patient per day ranged from 10-80mg. Pain intensity scores were assessed on a Likert pain scale. Concomitant pain medications or rescue medications were not allowed at any point during the 12-week treatment period.

This Remoxy study received a Special Protocol Assessment (SPA) from the FDA. With an SPA, the study design, endpoints and statistical analyses needed to support approval were agreed upon by the FDA prior to initiating the study and are considered binding.
Pursuant to an SPA, the primary endpoint was defined as mean decrease in pain intensity scores between Remoxy and placebo during the 12-week treatment period. Top-line data indicates that the study achieved a statistically significant result in its primary endpoint. In addition, the study achieved statistically significant results in secondary endpoints such as Quality of Analgesia and Global Assessment. No drug-related safety issues were noted in this study.

In 2005, King and Pain Therapeutics entered into a strategic alliance to develop and commercialise Remoxy and other opioid painkillers designed to deter common methods of abuse. Pain Therapeutics is substantially responsible for drug formulation, clinical development and regulatory filings for Remoxy and other opioid painkillers developed under this alliance. Upon regulatory approval, King will assume sole control and worldwide responsibility to exclusively commercialise Remoxy and the other opioid drugs that are part of the alliance. Remoxy and other opioid painkillers developed under this alliance are unique formulations of the patented Oradur platform technology licensed from Durect Corporation.

Pain Therapeutics is a biopharmaceutical company that develops novel drugs. The company has four drug candidates in clinical programs, including Remoxy, Oxytrex, PTI-202 and a novel radiolabeled monoclonal antibody to treat metastatic melanoma.