Two studies presented at the 2007 annual meeting of the American Association for Cancer Research (AACR) indicate that Erbitux® (cetuximab) improves treatment outcomes in patients with previously-treated metastatic colorectal cancer.
Colorectal cancer remains the second leading cause of cancer-related death in the United States. Metastatic colorectal cancer refers to cancer that has spread from the colon to distant sites in the body.
Erbitux is a type of targeted therapy called a monoclonal antibody. It works by binding to a protein receptor located on many cancer cells called the epidermal growth factor receptor (EGFR). EGFR is involved in cellular growth and replication, and by targeting EGFR, the spread of cancer can be reduced or delayed.
To evaluate whether the combination of Erbitux and the chemotherapy drug Camptosar® (irinotecan) is more effective than Camptosar alone, researchers conducted an international, Phase III clinical trial known as the Erbitux Plus Irinotecan in Colorectal Cancer (EPIC) study. The study enrolled more 1,298 patients with metastatic colorectal cancer that was resistant to Eloxatin® (oxaliplatin). Half the patients were treated with Camptosar alone and half were treated with a combination of Erbitux and Camptosar.
- Compared to patients treated with Camptosar alone, patients treated with Erbitux and Camptosar experienced a longer time to cancer progression.
- Overall survival did not differ between the study groups. The lack of a difference in overall survival may be due to the fact many patients initially treated with Camptosar alone began taking Erbitux after cancer progression.
- Side effects that were more common in patients taking both Erbitux and Camptosar included fatigue, diarrhea, and an acne-like rash.
The researchers conclude among patients with previously-treated metastatic colorectal cancer, the combination of Erbitux and Camptosar resulted in better progression-free survival than Camptosar alone.
In another study, researchers from Canada, Australia, New Zealand, and Singapore evaluated the effect of Erbitux among patients with metastatic colorectal cancer that had become resistant to all available chemotherapy drugs. The Phase III trial, known as CO.17, enrolled 572 patients. Half the patients received best supportive care alone (care given to alleviate symptoms and improve quality of life) and half received best supportive care along with Erbitux.
- Patients treated with Erbitux experienced improvements in both overall and progression-free survival. In the best supportive care group, half the patients survived longer than four-and-a-half months. In the best supportive care plus Erbitux group, half the patients survived longer than six months.
The researchers conclude that Erbitux improves survival and time to cancer progression among patients with chemotherapy-resistant metastatic colorectal cancer.
 Sobrero AF, Fehrenbacher L, Rivera F et al. Randomized Phase III trial of cetuximab plus irinotecan vs. irinotecan alone for metastatic colorectal cancer (mCRC) in 1298 patients (pts) who have failed prior oxaliplatin-based yherapy: The EPIC Trial. Presented at the 2007 meeting of the American Association for Cancer Research, Los Angeles, CA, April 14-18, 2007. Abstract LB-2.
Jonker DJ, Karapetis CS, Moore M et al. Randomized Phase III trial of cetuximab monotherapy plus best supportive care [BSC] versus BSC Alone in patients with pretreated metastatic epidermal growth factor receptor [EGFR]-positive colorectal carcinoma. A trial of the National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) and the Australasian Gastro-Intestinal Trials Group (AGITG). Presented at the 2007 meeting of the American Association for Cancer Research, Los Angeles, CA, April 14-18, 2007. Abstract LB-1.