Phosphagenics' oxymorphone patch storms phase I

Phosphagenics (ASX:POH) has completed the world’s first in-human trial of transdermal delivery of oxymorphone, with a phase I trial of its TPM/oxymorphone patch.

The patch was shown to deliver therapeutic plasma concentrations of oxymorphone in all 12 healthy volunteer subjects.

The participants each received repeated applications of a three-day sustained release TPM/oxymorphone pain patch, mimicking a real-life pain medication regime.

All 12 subjects demonstrated oxymorphone plasma concentrations well above the threshold therapeutic concentrations produced by the oral long-acting or extended-release dosage form of oxymorphone, Opana ER, within the first application period.

Phosphagenics said the results show that the maximum plasma concentration in subjects can be as high as that produced by the highest-strength Opana ER tablet, 40 mg. But TPM/oxymorphone only contains about 25% of the oxymorphone used in high dosage strengths of the pill form, reducing the potential for abuse.

“The importance of the success of this trial cannot be overstated. While we were confident going into the trial, the magnitude of the oxymorphone concentration in plasma surpassed our expectations,” Phosphagenics Chief Scientific Officer Dr Paul Gavin said.

“Not only can the patch deliver therapeutic amounts of oxymorphone, the results suggest that the patch can compete with the therapeutic value of the higher dosage strengths of the oral product and surpass them with respect to bioavailability.”

Phosphagenics CEO Harry Rosen said on the strength of the results that the company will shift its emphasis for a planned phase II trial from proving the product’s analgesic capabilities to defining the dosing regimes to be used with the product.

“The questions as to whether our opioid patch technology works have been categorically answered by these results. The task is now to work with our pain experts and regulatory consultants to progress the project through the next phases of the clinical trial and regulatory processes, as well as licensing discussions.”

The company aims to commence the phase II trial in mid-2014. Phosphagenics projects that peak sales of a successfully commercialised TPM/oxycodone could reach as high as $1.4 billion a year.

Phosphagenics also plans to commence a phase II trial of another opioid pain patch, TPM/oxycodone, in 2014.

Phosphagenics (ASX:POH) shares were trading 42.86% higher at $0.15 as of around 2.30 pm on Thursday.