Researchers at the National Cancer Institute first discovered paclitaxel's promise in 1963, but it never inspired much enthusiasm among drug companies because of a looming supply problem.

FORBES: Taxol's Next Stand

Along the way, for tax and supply diversification reasons, Bristol developed its own operation in Ireland to manufacture paclitaxel and then fired Hauser as a supplier.

FORBES: Delaying tactics

The drug is Taxol, Bristol's brand name for paclitaxel, a trace compound found in the bark of the Pacific yew tree in the northwestern U.S. During the 1970s researchers for the U.S. government's National Cancer Institute discovered that paclitaxel stops the growth of some cancerous tumors.

FORBES: Delaying tactics

Paclitaxel is "neither patented nor patentable, " a Bristol official assured Congress in 1991.

FORBES: Delaying tactics

But, on average, those who were taking cisplatin and paclitaxel survived for 9.8 months, compared to 8.5 months in those taking carboplatin.

BBC: Older lung cancer drug 'more effective'

Paclitaxel comes from the Pacific yew, a small, slow-growing fir found in small pockets in the Pacific Northwest. (Docetaxel comes from the European yew.) Devising a synthetic version is difficult because the chemical is exceedingly complex, marked by concentric rings of carbon, hydrogen, nitrogen and oxygen.

FORBES: Taxol's Next Stand