Australia-based QRxPharma has completed two phase I studies in healthy volunteers for MoxDuo CR, a controlled-release Dual-Opioid utilizing a 3:2 ratio of morphine and oxycodone.

The trials, conducted in healthy volunteers, evaluated the rate at which key components of the MoxDuo controlled-release (CR) formulation were absorbed, distributed, metabolized and eliminated by the body. The trials compared blood levels of MoxDuo CR's components to OxyContin and MS Contin and demonstrated MoxDuo CR's superior results, with sustained blood levels for up to 24 hours. Further studies indicated MoxDuo CR's increased resistance to tampering.

MoxDuo CR, a proprietary formulation, encompasses both sustained delivery technology and abuse deterrent and tamper resistant features. It is designed to provide at least 12 hours of analgesia in patients suffering from moderate to severe chronic pain including cancer, lower back, osteoarthritis and neuropathic pain.

"The successful completion of these trials confirms the advantages of this formulation and enables QRxPharma to initiate phase II proof-of-concept clinical studies mid-year 2012," said John Holaday, managing director and CEO of QRxPharma. "These data suggest MoxDuo CR may be positioned as a once or twice per day formulation for treating chronic pain, with the potential advantage of significantly reduced side effects as witnessed with immediate release MoxDuo. In the U.S. alone, the chronic opioid pain market is a $6 billion a year opportunity."

The first study compared MoxDuo CR (30mg morphine SO4/20mg oxycodone HCl) to the pharmacokinetic profiles of the same doses of MS Contin (30mg morphine SO4) and OxyContin (20mg oxycodone HCl) in 10 healthy adult human subjects using a three-way crossover design. Pharmacokinetic results from the measurement of opioid blood levels over time revealed a MoxDuo CR profile consistent with expectations for a once to twice-daily formulation.

The second study demonstrated that food consumption does not alter the pharmacokinetic profiles of morphine and oxycodone from MoxDuo CR (30mg/20mg) tablets using a two-way crossover design with 17 healthy volunteers. To demonstrate the effects of chronic use on steady-state blood levels, this study also measured the repetitive-dose pharmacokinetic profiles of morphine and its metabolites as well as oxycodone during repetitive (twice daily) administration of MoxDuo CR tablets for 5 days.

The MoxDuo CR tablets used in these clinical tests included QRxPharma's proprietary Abuse Deterrence Formulation (ADF) technology. As an indication of tamper resistance, attempts to extract morphine or oxycodone by crushing and solubilising in water or alcohol resulted in very limited (less than 15%) drug recovery. In addition, the ADF technology did not impair human bioavailability of the opioids following oral administration.

The CR formulation of MoxDuo encompasses the same 3:2 ratio of morphine and oxycodone as in MoxDuo IR, QRxPharma's immediate release acute pain formulation that is scheduled for PDUFA feedback from the FDA in June 2012. QRxPharma's U.S. partner for MoxDuo IR, Actavis, has the option to negotiate for the U.S. license of MoxDuo CR pending achievement of certain MoxDuo IR sales milestones in the acute pain market.

MoxDuo CR is expected to launch into the U.S. chronic pain market in 2015.