UK firm Vernalis testing Monash painkiller

New British biotech company Vernalis expects to complete Phase I clinical trials of a powerful new painkiller discovered by Monash University scientists by the middle of next year.

The promising new analgesic, designated R140, is a neurosteroid that has shown promising analgesic activity in laboratory models of acute and chronic pain -- including severe neuropathic pain associated with terminal cancers, diabetes and inflammatory disorders like arthritis.

A Monash University team led by Prof Colin Goodchild, head of the university's anaesthesia department, discovered and characterised R140.

Goodchild said R140 -- commonly known as alphadolone -- binds selectively to a GABAA receptor, a sub-type of the diverse family of GABA receptors that are also targeted by relaxants and anxiety-reducing drugs like barbiturates and benzodiazepines.

GABA-family receptors are present in 40 per cent of all synapses around the body, but the GABAA receptor is expressed exclusively by neurons in the central nervous system -- the brain and spinal cord. Activated GABA receptors inhibit nerve-cell activity.

Goodchild said that in addition to suppressing pain direcly, by binding to GABAA receptors and inhibiting the transmission of pain signals, iR140 also enhances the painkilling efficacy of narcotics like morphine and pethidine. Co-administration of R140 could allow doctors to minimise the dosage of powerful narcotics receptor reducing the risk of side-effects, including addiction and sleepiness.

R140 is taken orally, as a tablet, avoiding the inconvenience of injections or drips.

Goodchild said the market for novel therapies for chronic neuropathic pain was potentially huge. He said 60 per cent of diabetics develop diabetic neuropathy, and a significant number of these suffer chronic neuropathic pain. With the growing epidemic of type 2 diabetes in developed nations, doctors will be looking for more effective drugs to control chronic neuropathic pain.

In 2002, in a deal brokered by Melbourne biomedical business development company BioComm, the Vernalis Group acquired a licence to test and develop R140 from Monash Commercial, the university's commercial arm.

Last September, the Vernalis Group merged with British Biotech, to form a major new player in the British biotechnology sector, Vernalis.

The merged company already has a migraine drug, frovatriptan, on the market, and according to its CEO, Simon Sturge, it is keen to explore further collaboration opportunities with Victorian research institutions.

In the current Phase Ia clinical trial of R140, healthy volunteers have been given the drug either as a single dose, or four times daily for five days. The volunteers have tolerated the drug well, with no signs of sedation.

A Phase I proof-of-principle study will begin next year to determine its analgesic properties, and will be followed by a Phase IIa trial to determine its efficacy in patients with chronic neuropathic pain.