Maintenance treatment with cetuximab in a series of patients treated with standard chemotherapy and cetuximab in metastatic colorectal cancer.

Abstract

624 Background: New strategies are needed to improve outcomes and reduced toxicities of currently treatments for patients with advanced colorectal cancer. Nowadays maintaining treatment until disease progression is the standard option for these patients. Cetuximab is a recombinant humanized monoclonal antibody that neutralizes epidermal growth factor receptor and it has shown benefit not only in combination with standard chemotherapy in first- and second-line treatment or as a single agent in progression to standard chemotherapy in KRAS wild-type metastatic colorectal cancer (mCRC). Methods: This data describes patients who received standard chemotherapy with cetuximab every two weeks. For patients with response or stable disease, cetuximab was continued until disease progression or unacceptable toxicity. Results: Twelve patients are reported, nine were male (75%). The median age was 62 years (range, 46 to 78 years). All patients had stage IV, and liver was the most common location (75%). The majority of patients (75%) received FOLFOX VI as a first-line treatment in combination with cetuximab; only two patients were treated with FOLFIRI. Cetuximab was maintained after the first line of treatment in the 75% of patients. The median of cycles of chemotherapy and cetuximab was 12. Best response achieved in this setting was complete response (58.3%, 7/12). Median of monotherapy with cetuximab treatment was 7.5 cycles (range 3 to 12). At the moment of this analysis seven of twelve patients continued with the maintenance. In the rest of patients the treatment was followed until progression (33%, 3/12). No grade 3-4 toxicities were seen during maintenance cetuximab. The most common adverse effect during maintenance was cutaneous toxicity but the majority of patients had minor toxicity (50% grade 1). Conclusions: Cetuximab has significant antitumor activity not only as a single agent or in combination with standard chemotherapy but may also when it is used as maintenance therapy after a complete or partial response to first or second line based chemotherapy in mCRC. Maintenance cetuximab is feasible, safe, and worthy of future study in advanced colorectal cancer. No significant financial relationships to disclose.