Clinical

Cetuximab a first line option for metastatic colorectal cancer

Last Updated: 2007-06-06 15:32:29 -0400 (Reuters Health)

By Megan Rauscher

CHICAGO (Reuters Health) - The addition of cetuximab to FOLFIRI chemotherapy (5-FU, irinotecan, leucovorin) in the first-line treatment of EGFR-expressing metastatic colorectal cancer significantly increases response rates and prolongs disease-free survival by 15%, according to results of the first phase III study to evaluate this combination as first-line therapy for metastatic colorectal cancer.

These data suggest that cetuximab is "an additional first-line option" in these patients, said Dr. A. William Blackstock, moderator of a press briefing at the American Society of Clinical Oncology's annual meeting where the data were released.

Cetuximab (Erbitux) is currently approved by the FDA as second- or third-line therapy for advanced colorectal cancer.

In the study, 1198 EGFR-expressing metastatic colorectal cancer patients were randomized 1:1 to FOLFIRI plus cetuximab or FOLFIRI alone (control).

ASCO presenter and lead researcher Dr. Eric Van Cutsem from University Hospital Gasthuisberg, Leuven, Belgium, reported that median progression-free survival, the primary study endpoint, was 8.9 months in the combination arm compared with 8 months in the control arm, "which translates into a 15% risk reduction of progression." One-year progression-free survival rate was 34% with cetuximab versus 23% without.

"The addition of cetuximab to FOLFIRI was also associated with higher response rates and threefold higher complete resection rates for initially unresectable disease," Dr. Van Cutsem said.

Specifically, response rates were 46.9% with cetuximab versus 38.7% without and the number of complete resections (no residual tumor after resection) was 4.3% and 1.5%, respectively.

In a subgroup analysis, more than twice as many patients with liver metastases had their tumors completely removed in the cetuximab plus FOLFIRI arm (9.9%) compared to the FOLFIRI only arm (4.5%).

Side effects were manageable and generally similar in the two groups although more patients in the cetuximab arm experienced grade 3/4 diarrhea (15.2% vs 10.5%) and grade 3 skin reactions (18.7% vs 0.2%). "An important finding is that skin reactions showed a strong correlation with efficacy," Dr. Van Cutsem said.

Summing up, he said, "we don't cure patients with this treatment -- that's clear -- but it's pretty important that we can show that we can further improve on the activity of one of the standard treatment options -- FOLFIRI."