Cancer Drug Synthesized In Lab -- Taxol, Discovered In Yew Bark, Now Can Be Made Artificially

TALLAHASSEE, Fla. - A chemist says he has figured out how to use common chemicals to make the cancer-fighting drug taxol, the only source of which has been the scarce Pacific yew tree.

Florida State University researcher Robert Holton sees his advance as "important for cancer patients - but in years to come."

Taxol has shown promise mostly in the treatment of ovarian and breast cancers in women who have not responded to treatment with other drugs. It also has shown promise in early trials against certain lung cancers.

It takes the bark of about three full-grown trees to produce enough taxol to treat one cancer patient.

The trees thrive in the shade of the same dwindling old-growth forests that are home to the threatened northern spotted owl. Lawsuits to protect the owl habitat have brought logging to a virtual halt on national forests in the Northwest, where most of the yews are found.

Holton's report "may enable researchers to devise more effective, less toxic drugs of the taxol class and could thus have a significant effect on cancer treatment," said Samuel Broder, director of the National Cancer Institute. Broder has called taxol the most important cancer drug in 15 years.

But an alternative method using the twigs and needles of similar plants has been perfected and should be approved sometime this year, said Saul Schepartz, who oversees treatment research at the National Cancer Institute in Bethesda, Md.

That method, known as semisynthesis and discovered by Holton nearly three years ago, involves about four different chemical reactions.

Total synthesis - the laboratory production of taxol from common chemicals - involves some 40 different chemical reactions and takes about two weeks, Holton said.

"It's a significant lab accomplishment," Schepartz said.

He estimated at least a dozen labs nationally had been working on taxol synthesis.

Holton's team synthesized the drug last month and got word Monday that the Journal of the American Chemical Society would publish articles about the process.