Why would you choose to add bevacizumab to a chemotherapy regimen?
Bevacizumab has been shown across multiple studies to improve outcome in patients with metastatic colorectal cancer. Adding bevacizumab to FOLFIRI improves outcome, adding bevacizumab to irinotecan-based regimens overall seems to improve outcomes quite significantly. Bevacizumab added to an oxaliplatin regimen adds a little benefit, but significant enough to be considered somewhat meaningful. So bevacizumab overall seems to improve outcome when you add it to chemotherapy.
There seems to be some level of differential between bevacizumab and oxaliplatin-based regimens. If you look across the studies that have been conducted over the last few years, consistently you see that there is really good benefit when you add bevacizumab to irinotecan. With oxaliplatin, it's been less consistent, which questions if there is some slight superiority to the bevacizumab plus irinotecan-based regimen.
There was a study at ASCO GI, the MAVERICC study, that essentially compared FOLFIRI bevacizumab to FOLFOX bevacizumab in patients with metastatic colorectal cancer in the first-line. The study was a dead heat the two regimens performed equally well. However, there was a very clear trend in superiority with FOLFIRI plus bevacizumab in terms of survival and progression free survival. It didn't reach the level of statistical significance to consider this as a positive study, or favoring FOLFIRI, but it certainly had a trend that way.
Then you look at another study, CLGB80405, which didn't compare directly FOLFIRI plus bevacizumab and FOLFOX bevacizumab, but what the study suggested was that the group with FOLFIRI plus bevacizumab seemed to have done the best out of all the other groups. It makes you question whether it's a question of equivalency or if there's a slight advantage with bevacizumab plus irinotecan-based regimens.
Unresectable Colon Cancer: Case 1
68-year-old man was diagnosed with advanced, unresectable colon cancer has just started treatment with FOLFIRI plus bevacizumab.