A phase I trial of gefitinib and nimotuzumab in patients with advanced non-small cell lung cancer (NSCLC)

Background: Nimotuzumab (TheraCIM^®) is a humanized anti-epidermal growth factor receptor (EGFR) monoclonal antibody (mAb) with minimal skin toxicity. Combining a different class of anti-EGFR drug with gefitinib is a new strategy to overcome intrinsic and acquired resistance to gefitinib. The aim of this phase I trial was to determine recommended phase II dose (RPIID) and the safety of gefitinib and nimotuzumab combination treatment. Methods: Patients with advanced/metastatic NSCLC were treated with escalating doses of weekly nimotuzumab (100. mg or 200. mg, IV) and fixed doses of daily gefitinib (250. mg/day, PO) until disease progression or unacceptable toxicity. We planned to enroll 10 additional patients at RPIID to ascertain the safety of treatment. EGFR mutations and KRAS mutations were analyzed from available tumor samples. Results: A total of 16 patients were enrolled (3 in 100. mg cohort, 13 in 200. mg cohort). Six patients (37.5%) were female, and 5 (31.3%) were never smokers. Adenocarcinoma was the major histologic type (13 patients, 81.3%). Treatment was well-tolerated without dose-limiting toxicity (DLT). Four patients (25.0%) experienced grade 2 skin toxicity (1 in 100. mg cohorts, 3 in 200. mg cohort). Other common grade 1/2 toxicities were fatigue (37.5%) and diarrhea (25.0%). Among 16 evaluable patients, four patients (25.0%) achieved partial response and 7 patients (43.8%) had stable disease. Two of 4 responders had EGFR mutation (exon 19 deletion). Conclusions: Dual agent molecular targeting of EGFR with nimotuzumab and gefitinib in patients with advanced NSCLC is well-tolerated. The RPIID for nimotuzumab is 200. mg weekly IV and for gefitinib 250. mg/day PO. Based upon this phase I trial, we are planning to conduct a randomized phase II trial comparing gefitinib and nimotuzumab with gefitinib alone in patients with advanced NSCLC.