Antibodies to the epidermal growth factor receptor in non-small cell lung cancer: Current status of matuzumab and panitumumab

Matuzumab and panitumumab are antibodies against the epidermal growth factor receptor (EGFR) that are being evaluated in several malignancies including non -small cell lung cancer (NSCLC). In phase I trials of single-agent matuzumab in patients with EGFR-positive cancer, three tumor responses were documented in esophageal squamous cell carcinoma as well as colorectal carcinoma. A phase I trial of matuzumab in combination with paclitaxel has been reported in 18 patients with EGFR-positive advanced NSCLC. Objective responses were seen in 4 of 18 (23%) patients. A randomized phase II trial is currently ongoing in second-line NSCLC with matuzumab in combination with pemetrexed. A large dose/schedule trial of single-agent panitumumab enrolled 96 patients with EGFR-positive solid tumors. No responses were seen in the 14 lung cancer patients evaluated; 5 of 39 patients with colorectal cancers had objective responses. A randomized phase II trial of carboplatin/paclitaxel with or without panitumumab in 166 patients with previously untreated advanced stage IIIB/IV NSCLC did not find any benefit for the panitumumab arm compared with the chemotherapy alone arm with regard to response rates, time to disease progression, or median survival time. The lack of a biomarker to identify a subset of NSCLC patients who may derive benefit from this agent limits any potential enthusiasm for further trials of panitumumab at this time in NSCLC.