 Tarceva (Erlotinib) was OSI's and, as of 2007, only marketed product.Tarceva is a small molecule inhibitor of the epidermal growth factor receptor (EGFR) and is the only EGFR inhibitor to have demonstrated the ability to improve overall survival in advanced non-small cell lung cancer and advanced pancreatic cancer.Tarceva was discovered by Pfizer as CP-358774 (Moyer et al.