Pfizer Inc. (PFE) on Friday said it stopped a phase III study of an experimental drug to treat advanced pancreatic cancer when the results did not show any improvement in survival rates. The experimental dug axitinib was being used to try to shrink tumors in advanced pancreatic cancer but an independent monitoring board found no evidence that the drug prolongs survival and that resulted in the trials being halted.

"These results were disappointing, given the trend towards prolonged survival seen in a Phase II study of axitinib in this extremely difficult-to-treat patient population," said Mace L. Rothenberg of Pfizer's Oncology Business Unit.

The current standard of care for patients with the disease is treatment with Eli Lilly & Co.'s (LLY) chemotherapy drug Gemzar, or gemcitabine and the results of survival rates were compared with axitinib. Longer survival in patients treated with axitinib and gemcitabine, compared with gemcitabine alone was not seen by the board.

Axitinib, which is still being studied for kidney cancer in late stage clinical trials and is mid trial for non-small cell lung cancer, colon cancer and other tumor types, had shown promise in mid stage trials in treating pancreatic cancer in combination with chemotherapy. The company on the basis of these positive results decided to go ahead with larger and more expensive phase III trials on the drug.

Rothenberg said axitinib would continue to be tested in phase III trials for patients with renal cell carcinoma and Phase II trials in other tumor types, including advanced non-small cell lung cancer and colorectal cancer.

Pfizer, the world's largest drug maker, said it has notified all clinical trial investigators who were involved in the study as well as regulatory agencies about the results and has also recommended that patients should discontinue treatment with the drug axitinib.

This is the latest in a string of set backs for Pfizer in the research end for new drugs.  Cancer of the pancreas is a difficult to treat and often deadly disease which has no cure till now despite several drug companies trying to find more effective drugs for better treatment. Pfizer said it would try to develop other compounds that can be tested against pancreatic cancer.

Pancreatic cancer, the fourth-leading cause of cancer deaths in the U.S. has a low survival rate partly because its symptoms, which can include jaundice, often don't show up until the cancer is advanced and untreatable by surgery and resistant to chemotherapy and other drugs. In the past 20 years, only two treatments have been widely approved, with many other drugs failing in Phase III trials.