Alternate dosing of cetuximab for patients with metastatic colorectal cancer.

Background: Many chemotherapeutic regimens used to treat colorectal cancer (CRC), including 5-fluorouracil plus leucovorin in combination with irinotecan (FOLFIRI) or oxaliplatin (FOLFOX), are administered on an every-other-week (q2w) dosing schedule. Chemotherapy in combination with a monoclonal antibody (mAb) directed toward the epidermal growth factor receptor (EGFR) has emerged as an effective treatment option. There are currently 2 anti-EGFR mAbs approved by the United States Food and Drug Administration: cetuximab and panitumumab. Mutations of KRAS, a downstream protein in the EGFR pathway, predict resistance to EGFR mAbs. Thus, cetuximab and panitumumab are indicated for patients without a KRAS mutation (KRAS wild-type). Whereas panitumumab is approved on a q2w dosing schedule, cetuximab is approved as a weekly dose. However, only cetuximab is approved with FOLFIRI for frontline metastatic CRC, whereas panitumumab is approved for third-line. Because concomitant therapies are often administered q2w, the weekly dosing of cetuximab results in additional medical office visits.

Design: Several studies have assessed the safety and efficacy of cetuximab q2w. For this review, a comprehensive literature search of studies evaluating cetuximab q2w dosing was conducted. Safety and efficacy results of these trials and retrospective analyses were summarized and reviewed.

Results: In general, results with cetuximab q2w were comparable to those obtained with the weekly regimen.

Conclusion: These data suggest that for patients for whom weekly treatment with cetuximab presents a substantial burden to their quality of life, q2w dosing of cetuximab is a viable treatment option with a benefit:risk profile similar to that of the weekly regimen.