Erlotinib (CP-358774, OSI-774, Tarceva), a quinazoline derivative, is an orally active epidermal growth factor receptor tyrosine kinase inhibitor under development jointly by Genentech, OSI (formerly Oncogene Science) and Roche, both as monotherapy and combination therapy for the potential treatment of solid tumors, including non-small-cell lung cancer (NSCLC) and pancreatic, breast, head and neck cancers [203487]. Development of the compound is most advanced for NSCLC and pancreatic cancer; in July 2001, phase III combination trials were initiated for NSCLC [416835]. In October 2001, phase III monotherapy trials in NSCLC and phase III combination trials in pancreatic cancer were also initiated [426704]. In Japan, the compound was in phase I studies in January 2002 [439189].