Alternative Dosing Schedules for Cetuximab: A Role for Biweekly Administration?

The anti–epidermal growth factor receptor targeted monoclonal antibody (MoAb) cetuximab has established efficacy as a single agent and in combination with other modalities (chemotherapy, radiation therapy) in head and neck cancer and metastatic colorectal cancer. The agent is typically administered weekly; however, the development of a biweekly dosing regimen for cetuximab would provide treatment flexibility when combined with biweekly or longer chemotherapy regimens. The feasibility for biweekly dosing with cetuximab is supported by several factors. Biweekly dosing with MoAbs has been effective in multiple tumor types. Although cetuximab is currently administered on a weekly schedule, pharmacokinetic data demonstrate that cetuximab has a long terminal half-life, allowing administration of a biweekly schedule. Results from phase I studies show that a biweekly schedule of cetuximab is well tolerated, exhibits similar pharmacokinetics and pharmacodynamics to conventional weekly dosing, and does not seem to compromise efficacy. Additional studies are therefore warranted to further evaluate biweekly dosing for cetuximab in order to optimize treatment outcomes and convenience for patients.