Erlotinib in addition to gemcitabine significantly improves overall survival compared to gemcitabine alone in advanced pancreatic cancer (median overall survival 6.24 vs 5.91 months respectively). However, combined therapy has not become standard of care due to the modest absolute benefit. In NSCLC, the optimal efficacy of erlotinib is not in combination with first-line cytotoxic chemotherapy for advanced disease, but as a single agent after cytoxic chemotherapy. Preclinical and clinical data suggest that erlotinib will have activity as a single agent in advanced pancreatic cancer. The presence of an erlotinib-induced rash is associated with improved survival in phase II and III trials of diverse tumor types (reviewed by Perez-Soler et al.), and is associated with higher steady state concentrations of erlotinib.