CHICAGO, IL— First-line bevacizumab and cetuximab, when combined with chemotherapy, are equally effective for patients with metastatic colorectal cancer, according to research presented at the 2014 American Society of Clinical Oncology (ASCO) Annual Meeting.
“Our findings clearly show that the two antibodies—with either FOLFOX or FOLFIRI—are both acceptable and similarly effective,” said Alan P. Venook, MD, Madden Family Distinguished Professor of Medical Oncology and Translational Research at the University of California San Francisco, in San Francisco, CA. “This should reassure doctors and patients facing decisions about treatment selection.”
“With this finding, oncologists and patients have more ways to personalize cancer treatment,” commented ASCO President Clifford A. Hudis, MD, FACP. “They can be reassured that two widely used regimens offer good and equivalent survival.”
A total of 1,137 patients with previously untreated metastatic colorectal cancer were randomly assigned to receive bevacizumab plus clinician’s-discretion FOLFIRI (irinotecan/5-FU/leucovorin) or mFOLFOX6 (oxaliplatin/5-FU/leucovorin) chemotherapy, or cetuximab plus chemotherapy; overall, 73.4% of patients received FOLFOX chemotherapy.
At a median follow-up of 24 months, overall survival (OS) was 29.0 months for patients receiving bevacizumab, compared with 29.9 months for patients in the cetuximab group (hazard ratio [HR], 0.925; P = 0.34, not significant). Nor was progression-free survival (PFS) different between the two (10.8 vs. 10.4 months, respectively; P = 0.55, not significant). Outcomes did not vary by gender. “These [results] are essentially the same,” Dr. Venook concluded.
No new treatment toxicities were reported and there were 10 drug-related deaths. Common adverse events for bevacizumab included hypertension, headache, mouth sores, nosebleed, diarrhea, rectal bleeding, decreased appetite, fatigue and weakness. The most common cetuximab toxicities were acneiform rash, itching, nail toxicity, infections, fatigue, and low blood electrolytes.
“Expanded RAS and other molecular and clinical analyses may identify subsets of patients who get more or less benefit from specific regimens,” Dr. Venook said. Those analyses are forthcoming, he added.
About 75% of the 50,000 Americans diagnosed with metastatic colorectal cancer each year are initially administered a bevacizumab-based therapy, Dr. Venook noted.
- Venook AP, Niedzwiecki D, Lenz HJ et al. Abstract LBA3. Presented at: 2014 American Society of Clinical Oncology (ASCO) Annual Meeting; May 30-June 3, 2014; Chicago, IL.