Phase II clinical trial data with the epidermal growth factor receptor tyrosine kinase inhibitor erlotinib (OSI-774) in non-small-cell lung cancer

Erlotinib (OSI-774; Tarceva™) is an orally available, highly specific epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor. The results of 3 phase II studies with erlotinib in non-small-cell lung cancer (NSCLC) are reviewed herein: (1) in patients with chemotherapy-resistant, HER1/EGFR-expressing NSCLC of all histologies, (2) in patients with bronchoalveolar carcinoma previously untreated or treated with chemotherapy, and (3) as first-line therapy in elderly patients with NSCLC of all histologies. These studies have evaluated tumor response, survival, and symptom improvement. Erlotinib was given as an oral, continuous daily dose of 150 mg. The drug was well tolerated; drug-related cutaneous rash and diarrhea were observed in approximately two thirds of patients. Withdrawals caused by toxicity were rare. The response rates were 12.3%, 25%, and 13.3%, respectively. Mature survival data are available for the first trial. The median survival was 8.4 months, and the 1-year survival rate was 40%. All responding patients in the first and second trials presented skin rash. In addition, survival correlated with the occurrence and severity of rash in the first trial. No data on the correlation between rash and survival are available for the second and third trials. Erlotinib is active and well tolerated in patients with NSCLC as first- and second-line therapy. Cutaneous rash appears to be a surrogate marker of clinical benefit, but this finding needs to be confirmed in ongoing and future studies.