Blocking tumours

Drugs that combat growth of cancer by blocking blood supply lines for tumours are being tried for the
first time on humans. These new compounds disrupt the chemical signals exclusive to tumours and thus will have fewer side effects. All the five new molecules discovered by Sugen, a California-based company, block angiogenesis -- the formation of fresh blood vessels. Such experiments have been found to successfully halt tumour growth in mice. While the new drugs are expected to shrink or eradicate the tumours, if they simply keep the tumour in check, patients may have to take regular doses for the rest of their lives.