Novel cancer drug

Novel cancer drug shows early promise in phase l trial

LONDON (Agence de Presse Medicale for Reuters Health) - A prototype cancer drug that blocks the heat shock protein 90 (Hsp90) appears to be able to attack tumours on many different fronts simultaneously, according to results of a phase l study in 30 patients published in the Journal of Clinical Oncology.


Hsp90 protein is found in high levels in tumor cells and helps maintain the shape, stability and function of many molecules that play critical roles in the development of cancer.

The investigational drug -- 17AAG -- was administered intravenously once weekly to patients with advanced melanoma, sarcoma, mesothelioma, breast, colon, ovarian, renal, non-small cell lung, pancreatic, peritoneal or parotid cancer or cancers of unknown origin.

Researchers at the Royal Marsden Hospital in London measured the levels of two of the molecules vital for cancer growth -- c-RAF-1 and CDK4 -- and found that they consistently fell in response to the drug.

"The results suggest that by blocking the action of Hsp90 the drug has the potential to attack cancer by shutting down a range of systems that cancer cells use to grow and spread," said lead researcher, Paul Workman, of the Cancer Research UK Centre for Cancer Therapeutics at The Institute of Cancer Research.

John Toy, Cancer Research UK's medical director, added in a statement: "What's particularly exciting about this drug is that it targets so many different features of cancer's machinery all at once, which should make it much more difficult for tumours to develop resistance to treatment."

The drug, also known as KOS-953, was provided to the British scientists by the National Cancer Institute in the United States under an agreement with the US biotech company, Kosan Biosciences Inc.