http://www.cnn.com/2003/HEALTH/conditions/06/02/cancer.bloodblocker.ap/index.html

Study: Blood blockers aid cancer survival

Tuesday, June 3, 2003 Posted: 8:58 AM EDT (1258 GMT)

Dr. Herbert Hurwitz, left, and Dr. Robert Mayer, address reporters Sunday in Chicago. Story Tools

CHICAGO, Illinois (AP) -- The benefits so far are small, but a new study proves scientists pursuing one of cancer treatment's most intriguing theories -- that the way to attack a tumor's heart is through its blood supply -- at least are on the right track.

In a separate study presented at the American Society of Clinical Oncology, doctors concluded Erbitux, the cancer drug that enmeshed ImClone Systems in an insider trading scandal, worked just as well as an earlier company-sponsored study said it did. (Full story)

Shares of the two cancer drugs' makers soared Monday on the news of the promising results.

The research targeting a tumor's blood supply was developed around the idea that cancer needs a growing network of blood vessels to survive -- a theory championed by Harvard University's Dr. Judah Folkman. According to the theory, shutting down the process, called angiogenesis, should arrest tumors and even obliterate them.

After decades of obscurity, Folkman's theory became front-page news in 1998 with reports his angiogenesis-blocking drugs cured mice. Some predicted he was on the verge of curing human cancer, too.

Proving that has been difficult. However, on Sunday, researchers released a study of Genentech's experimental angiogenesis stopper, Avastin, which showed the drug modestly lengthened survival -- notable in a field where even inch-by-inch improvement can be hard to document.

"This is a landmark announcement," said Dr. William Li, head of the nonprofit Angiogenesis Foundation. "It's the first true validation in a well-designed clinical trial that cutting off a tumor's blood supply can improve cancer survival."

The treatment is an antibody aimed against vascular endothelial growth factor, or VEGF, one of the more than 20 chemicals that help tumors' blood vessels grow and survive.

The study, directed by Dr. Herbert Hurwitz of Duke University, involved 925 colon cancer patients who all received a standard chemotherapy cocktail of irinotecan, 5-fluorouracil and leucovorin. They were also randomly given either Avastin or a dummy placebo.

Those on Avastin survived an average of 20 months, compared with nearly 16 months in those getting only standard treatment. The results were a surprise, since an earlier study found no benefit of Avastin against breast cancer.

Dr. Mace Rothenberg of Vanderbilt said when he was in medical school, such patients typically survived just six months. "This improves median survival by about 30 percent," he said. "When you put it in those terms, it is very meaningful to patients."