An anti-cancer drug based on the research of a Harvard professor has passed the clinical trial stage—a major milestone for any treatment.

The drug, Avastin, extended the life of colon cancer patients in a recent study. According to medical experts, the successful results of Avastin validate the theory of Andrus Professor of Pediatric Surgery Judah Folkman regarding tumor growth.

Avastin must now wait for approval by the Food and Drug Administration (FDA), which researchers expect will occur by the end of this year. The drug is not expected to be a cure for cancer—doctors hope instead that it could serve as a helpful accompaniment to traditional chemotherapy programs.

Folkman theorized that tumors multiply by growing their own blood vessels, an idea originally shunned by many medical professionals. Tests of Avastin, however, demonstrated that the growth of tumors could be slowed by decreasing their blood supply.

“If something works in patients, it validates all the previous scientific research,” said Folkman. “It’s very exciting.”

In tests, Avastin increased the rate of tumor shrinkage and delayed relapses for longer, without the side effects of other cancer treatments, said William W. Li ’84, president and medical director of the Angiogenesis Foundation, a non-profit organization.

“The new Avastin announcement is the first major triumph in this field,” Li said. “This marks a turning point in the war against cancer because it proves for the first time that Dr. Folkman’s theory is correct.”

With the recent success of Avastin “all this laboratory work, for the first time in the last few years, is being translated from the lab to the bedside,” Folkman said.

Avastin, made by San-Francisco-based Genentech Inc., is injected into patients and acts as a honing missile that neutralizes a protein that redirects blood flow to tumors.

Li describes this process—called antiangiogenesis—as the prevention of the growth of new blood vessels in the body, as “one of the most exciting new frontiers of cancer research.”

The development of Avastin only took six years—a pace Li described as “break-neck speed.”

Folkman’s research on vessel growth began in 1971, Folkman said.

While in the mid 1980s angiogenesis was a field studied by a very small and elite group of researchers, according to Li, it has “exploded in intensity” in the past 15 years,—becoming “a global research field.” Over 1,000 labs around the world that pursue angiogenesis research, he said.

—Staff writer Faryl W. Ury can be reached at ury@fas.harvard.edu.