Patients with advanced non-small cell lung cancer now have the option of receiving a targeted drug immediately after chemotherapy--before the disease worsens.Late Friday, the Food and Drug Administration approved Tarceva (erlotinib) as maintenance therapy for patients with locally advanced or metastatic lung cancer that has not progressed after first-line chemotherapy. Until now, the approved use of Tarceva had been limited to advanced lung cancer that grew or spread after chemotherapy. (Check out "Lung Overdue" from the Spring 2010 issue.)Surprisingly, the approval came despite an FDA advisory panel's almost unanimous vote last December against the new use. The panel's main concern was the minimal benefit shown in the SATURN study, which served as the basis for the approval.In the trial, nearly 900 patients with advanced non-small cell lung cancer received four cycles of first-line platinum-based chemotherapy. Patients were then split into two groups: one received placebo, and the other received maintenance Tarceva. For patients on Tarceva, median progression-free survival (the time before the cancer progressed) reached 12.3 weeks, compared with 11.1 weeks for patients taking placebo. The Tarceva group lived only slightly longer, with median overall survival reaching 12 months for patients on Tarceva versus 11 months for those on placebo. The most common side effects of Tarceva included rash and diarrhea.Tarceva, also approved for advanced pancreatic cancer, is an oral drug that inhibits the EGFR signaling pathway inside a cancer cell. OSI Pharmaceuticals, the maker of Tarceva, is investigating the drug as a first-line treatment in lung cancer patients with an EGFR mutation, as treatment after surgery for non-small cell lung cancer, and for treating ovarian cancer and liver cancer, the company said in a statement.Check out our lung cancer page for more.