<h4>Background</h4>We investigated the safety and antitumor activity of dalotuzumab, a selective anti-insulin growth factor 1 receptor monoclonal antibody (IGF1R MoAb), plus erlotinib in a sequential phase I/II trial in unselected patients with refractory advanced non-small-cell lung cancer (NSCLC).The phase I trial determined the recommended dose and safety of erlotinib plus dalotuzumab at 5 mg/kg or 10 mg/kg weekly in 20 patients. Here, IGF1R is linked to non-small cell lung carcinoma.