Drug giant Pfizer has pulled the plug on a late-stage trial investigating its experimental oncology drug axitinib as a treatment for advanced pancreatic cancer, after the drug failed to show any survival benefit in patients.

The company had had high hopes for axitinib in this setting, as results from earlier studies in pancreatic cancer patients - who currently have very few treatment options - were encouraging, but an early analysis of data by an independent safety monitoring board found no evidence that the drug was any better at prolonging life than chemotherapy alone.

“These results were disappointing, given the trend toward prolonged survival seen in a Phase II study of axitinib in this extremely difficult-to-treat patient population,” commented Mace Rothenberg, head of Pfizer's oncology business unit.

Rothenberg went on to say that the company remains committed to the development of axitinib in other cancers, and the drug is still being assessed in Phase III trials for kidney cancer, as well as in earlier trials in kidney, colon and non-small cell lung cancer. But its failure in pancreatic cancer will be seen as a setback for Pfizer and, in particular, its quest to fill the void in sales when its multi-billion-dollar cholesterol-lowerer Lipitor loses patent protection in 2011.

According to media reports, shares in the company are currently trading at a 12-year low, and with investors failing to show much enthusiasm for the firm's recently-announced proposed acquisition of Wyeth for $68 billion, this latest news is only likely to blacken the mood further.