Tarceva (previously known as OSI-774) is an orally active, potent, selective inhibitor of the EGFR tyrosine kinase. Early clinical data with Tarceva indicate that the compound is generally safe and well tolerated at doses that provide the targeted effective concentration based on nonclinical experiments. A recently completed, randomized, double-blind, placebo-controlled trial (BR.21) has shown that Tarceva as a single agent significantly improves the survival of patients with incurable Stage IIIb/IV NSCLC who have failed standard therapy for advanced or metastatic disease (Shepherd F et al, 2000 and 2005). In a Phase II clinical trial (Jackman D et al, 2007) of 80 chemotherapy-naive patients >70 years of age with advanced non-small cell lung cancer who received erlotinib as first-line therapy, an encouraging median survival time (MST) of 10.9 months was reported, with the presence of EGFR mutations strongly correlated with disease control and survival.