In a nutshell
This study compared two biologic drugs (drugs extracted from biological sources) for treating metastatic (spread to other areas of the body) colorectal cancer.
Some background
Metastatic colorectal cancer is often treated with combinations of chemotherapy drugs. One common combination is called FOLFIRI, and includes the agents 5-fluorouracil [Efudex], leucovorin and irinotecan [Camptosar]. Combining FOLFIRI with biologic drugs, however, can improve patient outcomes.
Two common biologic drugs are as cetuximab (Erbitux) and bevacizumab (Avastin). These drugs work in different ways to slow cancer growth. Some tumors depend on the epidermal growth factor receptor (EGFR) protein for growth. Cetuximab slows cancer growth by blocking EGFR. Tumors depend on new blood vessels in order to grow and spread. Bevacizumab blocks the formation of new blood vessels in tumors. It is not clear whether cetuximab plus FOLFIRI or bevacizumab plus FOLFIRI is a better first treatment option for patients.
Methods & findings
This study compared treatment with cetuximab plus FOLFIRI (297 patients) to bevacizumab plus FOLFIRI (295 patients) in metastatic colorectal cancer patients. All patients had a normal KRAS gene (wild-type; mutations in this gene can cause cancer growth) and had not been treated for metastatic cancer before the study. Overall survival time (time following treatment before death from any cause), progression-free survival (time following treatment before the disease progresses) and adverse events were examined.
The average progression-free survival was similar for both groups, 10.0 months for the cetuximab group and 10.3 months for the bevacizumab group. The average overall survival time was significantly longer for patients in the cetuximab group (28.7 months) than in the bevacizumab group (25 months).
The rates of adverse events were similar for the two drugs. The most common serious adverse events were hematotoxicity (damage to red blood cells; 25% of the cetuximab group and 21% of the bevacizumab group), skin reactions (26% of the cetuximab group and 2% of the bevacizumab group) and diarrhea (11% of the cetuximab group and 14% of the bevacizumab group).
The bottom line
The authors concluded that bevacizumab and cetuximab were both safe and both slowed disease progression. However, as cetuximab improved patient survival they suggest that it might be a better option for treating patients with KRAS wild-type metastatic cancer.
The fine print
This study was funded by Merck KGaA who also distribute cetuximab.
Published By :
Lancet oncology
Date :
Jul 31, 2014
