Study shows why pancreatic cancer drug may fail

*Study suggests why pancreatic cancer drugs can fail

*Finding could lead to better treatment

*Combination of two drugs showed promise in mice

By Michael Kahn

LONDON, May 21 (Reuters) - A poor network of blood vessels may explain why some people with pancreatic cancer are often resistant to a common chemotherapy treatment, international researchers said on Thursday.

A study by Cancer Research UK found that pancreatic cancer can spread quickly to a tumour, despite a healthy blood supply, and gave evidence why conventional cancer treatments such as Eli Lilly and Co's (LLY.N: Quote, Profile, Research) Gemzar were often ineffective.

The study found that combining cancer treatment Gemzar with Infinity Pharmaceutical's (INFI.O: Quote, Profile, Research) experimental drug IPI-926 made the treatment work better in mice with pancreatic cancer.

The findings could lead to better ways to treat one of the most deadly cancers -- one that only three percent of patients survive for five years or more, said David Tuveson, a researcher at Cancer UK's Cambridge Research Institute, who worked on the study.