BioWorld International Correspondent

LONDON - Clinuvel Pharmaceuticals Ltd. added prevention of phytoxicity associated with photodynamic therapy (PDT) treatment of cancer to the list of applications for its lead product CUV1647. That brings to five the number of indications found for the compound since the company dropped plans to develop it as a sun-tanning agent and focus on its potential use as a treatment for ultra-violet-related skin disorders.

Philippe Wolgen, CEO, took over the helm in November 2005 after the Melbourne, Australia-based company, then known as EpiTan, failed to pull off an IPO on London's Alternative Investment Market in May of that year. He has since refinanced the company, changed its name and changed its development strategy.

"If you inject a drug systemically [as is the case with CUV1647], it needs to meet all the regulatory requirements," Wolgen told BioWorld International. "That gave away which route we needed to go."

In parallel with sun tanning (and by implication protection from melanoma) EpiTan had developed CUV 1647, then known as melanotan, as a treatment for the sun allergy polymorphous light eruption (PLE), giving the renamed and refinanced Clinuvel a platform on which to build.

At the beginning of the year, the UK regulator, the Medicines and Healthcare Regulatory Agency (MHRA), gave approval to begin a Phase III trial in PLE. Clinuvel expects to begin multicenter European trials in the indication in April or May, making it only the third Australian biotech to reach this stage of product development.

In addition, CUV 1647 is ready to enter Phase III in erythropoietic protoporphyria, a genetic condition that causes an absolute intolerance to sunlight. In Phase II results announced in February, CUV 1647 significantly delayed the onset of pain caused by light exposure.

The fourth indication is squamous cell carcinoma/actinic keratosis induced by the anti-rejection medication given to organ transplant patients, and the fifth solar urticaria.

Last week Clinuvel filed a patent on the use of CUV 1647 in PDT and said it will soon seek approval to conduct a trial using the compound as an adjunctive treatment to prevent the photosensitivity, both to sunlight and artificial light, that PDT patients experience.

In its most recent funding round, Clinuvel, which is listed on the Australian Stock Exchange, raised A$35.2 million (US$28.4 million). Wolgen said the company is adequately financed until mid-2008.

CUV 1647 has a long history, dating back to the mid- 1980s when scientists at the University of Arizona theorized that using the naturally occurring hormone, alpha melanocyte-stimulating hormone to induce the body's natural tanning system to tan in advance of exposure to sunlight, might provide a defense against melanoma.

The hormone has a half-life measured in seconds, but they developed a number of analogues, of which CUV 1647 is one. The compound has a much longer half-life, measured in minutes, and is administered as an implant, which is the size of a grain of rice. The implant lasts for 60 days. To date, 335 patients have been treated with the product.