A promising anti-cancer drug developed by Dr. M. Judah Folkman, a Harvard Medical School professor, has passed safety testing and will go into human trials at the Mayo Clinic.

Folkman, who is Andrus professor of pediatric surgery, has researched cancer drugs for over three decades.

Researchers announced on Wednesday that it would be safe to extend human trials on Folkman's cancer-fighting drug, called 2ME2 (2-methoxyestradiol).

The drug, which can be taken as a pill, has at least one advantage over other cancer treatments. Most traditional cancer treatments--such as surgery, chemotherapy and radiation--try to kill tumor cells directly, but 2ME2 also prevents angiogenesis, the growth of new cancerous blood vessels in the body.

Folkman said that the recent advancement in the testing for 2ME2 marked an important step in the development.

"In the first phase, the question is, 'At what dose do you start to see side effects?'" Folkman said. "In the second phase, it is primarily, 'How effective is it?'"

Folkman said he could not speculate on how quickly, if ever, the drug would be widely available.

The drug works well on mice, he said, but that does not mean it will perform well in human trials.