Avastin plus chemo better without Erbitux

CHICAGO (Reuters) - Colon cancer patients treated with Genentech Inc's Avastin and chemotherapy lived longer without their disease getting worse than those who were also treated with ImClone Systems Inc's Erbitux, according to a study presented on Saturday.

In the 755-patient study, those in the Avastin (bevacizumab) plus chemotherapy group had median progression-free survival of 10.7 months, researchers said.

With Erbitux (cetuximab) added to the mix, median progression-free survival fell to 9.8 months, according to data presented at the American Society of Clinical Oncology meeting in Chicago.

When measuring median overall survival, the results from both groups were comparable: 20.4 months versus 20.3 months in the Erbitux group, researchers said.

Patients in the triple combination arm had a 10 percent higher incidence of serious side effects, which was mainly attributed to Erbitux-related skin toxicity.

The results mirror those seen in a trial of Amgen Inc's Vectibix (panitumumab), which, like Erbitux, is an antibody designed to block a protein called epidermal growth factor.

Amgen last year halted a key trial after finding that colon cancer patients treated with just chemotherapy and Avastin had a better chance of survival than patients who also received Vectibix.

(Reporting by Bill Berkrot and Deena Beasley; Editing by Tim Dobbyn)