CALGB 80405, a large, independent, phase III study, designed to assess the superiority in overall survival (OS) of cetuximab over Avastin® (bevacizumab) when combined with either FOLFOX or FOLFIRI chemotherapy in people with previously untreated, KRAS wild-type advanced (metastatic) bowel cancer1 has failed to meet this primary endpoint. Instead the study found both medicines help give patients almost 30 months of extra life (median OS of 29.9 months for patients in the cetuximab treatment arm versus 29.0 months for patients in the Avastin treatment arm [HR=0.92, p=0.34]).1 The secondary endpoint of progression-free survival (PFS) was also similar between treatments.1 Adverse events were as expected for both medicines.1 The CALGB 80405 data were presented at the 2014 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, during a plenary presentation reserved for abstracts "deemed to have the highest scientific merit and greatest impact on cancer research and care."2

"The CALGB 80405 data address the question of which medicine is the most appropriate first-line treatment for patients with KRAS wild-type disease and reinforce the role of Avastin as an efficacious and valid treatment option for advanced colorectal cancer patients regardless of KRAS status," commented Dr Sherif Raouf, Consultant Clinical Oncologist at Barking, Havering and Redbridge University Hospitals NHS Trust. "Results of the study also highlight the significant progress made in improving outcomes for people with bowel cancer and are important news for the 41,500 patients diagnosed with the disease every year in the UK."

Results from CALGB 80405 reinforce that Avastin is helping some patients with advanced bowel cancer live longer than ever before.1 While more than 10 years ago, the average (median) survival for patients with newly diagnosed advanced bowel cancer was little over a year (15 months),3 median overall survival for patients without mutations in the KRAS gene (KRAS wild-type patients) treated with Avastin in this study was almost two-and-a-half years (29 months).1

This study reinforces that Avastin plus chemotherapy remains an efficacious and valid treatment option for the initial treatment for most patients regardless of biomarker (KRAS) status.

About CALGB 804051

The primary endpoint of the study, an improvement in overall survival of cetuximab compared to Avastin in patients with KRAS wild-type metastatic bowel cancer, was not reached; both medicines helped patients in this study live a similar length of time (median OS of 29.9 months for patients in the cetuximab treatment arm versus 29.0 months for patients in the Avastin treatment arm [HR=0.92, p=0.34]). The CALGB 80405 study results are clinically important as they address the question about which medicine may be the most appropriate first-line treatment for patients with KRAS wild-type metastatic bowel cancer. CALGB 80405 informs physicians that Avastin is similarly effective, as a first-line treatment in KRAS wild-type metastatic bowel cancer.