Avastin proves disappointing for Roche/Genetech in two studies at ASCO GI

Two Phase III studies presented this month at the American Society of Clinical Oncology's gastro-intestinal meeting in Orlando, Florida, were disappointing for Avastin (bevacizumab) although one of the two met its primary endpoint.

In one study, the vascular endothelial growth factor inhibitor, co-developed by Swiss drug major Roche and US biotechnology major Genentech, was studied primarily for its effect on progression-free survival in metastatic colorectal cancer (mCRC). Avastin was compared against placebo as first-line therapy in combination with two oxaliplatin-containing regimens. In a further study in advanced pancreatic cancer, it was investigated for impact on overall survival alongside gemcitabine or placebo.

In the randomized, 1,400-patient, Phase III XELOX-1/NO 16966 trial of first-line Avastin and oxaliplatin-based therapy in mCRC, lead investigator Leonard Salz said the drug added a statistically significant 17% relative improvement in progression-free survival with an absolute difference of 1.4 months. But, he added: "this is a more modest improvement than we hoped to see based on the four-month difference seen in previous studies in front-line settings."