Safety and Efficacy of Panitumumab in the Treatment of Metastatic Colorectal Cancer

Therapies targeting epidermal growth factor receptor (EGFR) are a promising recent development in the treatment of metastatic colorectal cancer (mCRC). Panitumumab is a fully human anti-EGFR monoclonal antibody that competitively inhibits the binding of all known EGFR ligands, including epidermal growth factor and transforming growth factor alpha, to cells expressing EGFR. In patients with mCRC, panitumumab monotherapy has resulted in favorable clinical responses, including increases in objective response rate, stable disease rate, and progression-free survival. Panitumumab has also shown promising antitumor activity in combination with selected chemotherapy regimens. Responses and improvements in progression-free survival associated with panitumumab monotherapy in patients with mCRC appear to be confined to patients whose tumors express wild-type KRAS. Therapy with panitumumab is generally well tolerated; the most common adverse events observed include skin-related toxicities, gastrointestinal toxicities, and hypomagnesemia. Infusion reactions are rare, and the agent has low immunogenicity.