In an attempt to elude the pesky pumps and overcome mutations, Bristol-Myers scientists engineered more than 1, 200 taxane molecules.

FORBES: Taxol's Next Stand

Epothilone has the potential to be even more effective against taxane resistance because it has a different chemical structure that may let it bind better with microtubules.

FORBES: Taxol's Next Stand

Now, after years of fruitless efforts to deal with taxanes' shortcomings, Bristol-Myers (nyse: BMY - news - people ) and rival Aventis (nyse: AVE - news - people ) (which produces another taxane called docetaxal, under the name Taxotere) each have promising new variations.

FORBES: Taxol's Next Stand