Maintenance Therapy in Colorectal Cancer

Exploring the effectiveness of maintenance therapy in colorectal cancer (CRC) is essential to the experimental development of new treatments, says Dirk Arnold, MD, PhD. The disease is controlled in this setting, with only a small amount of tumor cells having survived aggressive induction treatment. It is important to understand which clones have survived induction therapy, says Arnold.

The phase III DREAM study assessed the value of maintenance therapy with bevacizumab and the EGFR inhibitor erlotinib versus bevacizumab alone following 6 cycles of induction therapy with FOLFOX (fluorouracil, leucovorin, and oxaliplatin) plus bevacizumab. However, this study did not include a standard treatment as a comparator arm, notes Arnold. Overall, the study found that bevacizumab plus erlotinib improved progression-free survival compared with bevacizumab alone; however, overall survival was not prolonged.Active maintenance therapy is better than no maintenance therapy at all, specifically following induction therapy with a bevacizumab-based treatment, comments Arnold. In this setting, a moderately dosed fluoropyrimidine or oral fluoropyrimidine with bevacizumab is an effective option. In many settings, following induction with FOLFOX and bevacizumab the leucovorin and oxaliplatin are dropped from the chemotherapy regimen and 5-FU and bevacizumab are continued during a maintenance phase, suggests Fortunato Ciardiello, MD, PhD.

Although it is an effective option, maintenance therapy is sometimes stopped early because of the costs, states Ciardiello. Immunotherapy or another class of drugs could play a role at this stage of the disease, adds Ciardiello. Given the activity of these agents, the term “maintenance” may not be accurate in certain circumstances.