Acid test for EpiTan

Melbourne biotechnology company EpiTan (ASX: EPT) has received approval from the Royal Prince Alfred Hospital Ethics Committee in Sydney to proceed to Phase IIb clinical trials of its tan-inducing compound Melanotan next month.

The company announced yesterday that Prof Ross Barnetson, a world authority on sunburn and skin cancer, will conduct the eight-month trial, which will involve 80 healthy human volunteers.

The trial follows the recent success of EpiTan's Phase I clinical trial which confirmed that Melanotan is well tolerated by human volunteers.

The Phase IIb trial will assess Melanotan's ability to reduce the severity and toxicity of sunburn.

EpiTan's manager of clinical development, Dr Stuart Humphrey, said the volunteers will be screened by administering a standard dose of ultra-violet radiation on a 1cm square of skin on the back -- enough to cause erythema, or reddening of the skin, in lighter-skinned patients.

The selected volunteers will then be irradiated with a UV dose three times as strong, sufficient to cause damage to the epidermis -- again, in the small of the back, which is rarely exposed the sun.

Small biopsies will then be taken to assess the degree of damage compared with unexposed skin from an adjacent site.

Volunteers will be the administered Melanotan at 10-day intervals over the next three months to induce tanning, and the irradiation experiment will be repeated to determine how effective the drug is at preventing sunburn and the type of epidermal damage and immunosuppression that leads to skin cancer in susceptible individuals.

Melanotan is a synthetic compound that mimics the activity of a natural skin hormone, alpha-MSH, which stimulates melanocytes to secrete melanin, the protective that causes the skin to tan.

Research indicates that Melanotan is around 1000 times more potent than alpha-MSH. It induces tanning even without exposure to sunlight, and the tanning effect is more prolonged.

"If you get a tan using Melanotan, then maintain the tan, evidence suggests you will suffer less skin damage,' Dr Humphrey said.

He said there was clear epidemiological evidence that tanning prevented sunburn and reduced the risk of skin cancer. Individuals with high levels of melanin have much lower rates of sunburn and skin cancer than fair-skinned individuals -- white Americans have skin cancer rates around 100 times higher than African-Americans.

EpiTan managing director Dr Wayne Millen said there was a major unsatisfied medical need for a drug that can reduce sunburn and skin damage. The company estimates the potential world market for Melanotan at $3 billion.