A new drug shows promise for fighting breast and lung cancer, a government panel declared, but the panel scolded the maker for promoting it without hard evidence.

A Food and Drug Administration advisory committee said that despite early indications Taxotere may fight certain cancers better than available drugs, it should not be sold because it hasn't been tested sufficiently.As for that research: "Get on with it, do it," Dr. Paul Bunn of the University of Colorado told Taxotere maker Rhone-Poulenc Rorer.

Taxotere is being developed to fight advanced breast and lung cancer that doesn't respond to standard chemotherapy. There is no treatment for such lung cancer patients. Breast cancer patients typically take the popular drug Taxol, a close cousin of Taxotere.

FDA had invited Rhone-Poulenc to seek approval with the knowledge that it had only preliminary data, said chief executive Robert Cawthorne. Yet the FDA's advisory committee decided Tuesday those data were not sufficient.

"Obviously we were a bit surprised and disappointed," Cawthorne said. "FDA was very interested in Taxotere; they see it's potentially an important drug."