To my knowledge Tarceva is farily new and is still going through clinical trials.
Found this on another page:
Q. What is Tarceva? A. Tarceva is a pill you take by mouth to treat Non-Small Cell Lung Cancer (NSCLC). Tarceva is approved to treat locally advanced or metastatic NSCLC after at least one prior chemotherapy regimen has not worked.
Q. How does Tarceva work? A. Tarceva is a targeted treatment. It is designed to block tumor cell growth by targeting a protein called HER1/EGFR. This protein, which is present on the surface of some cancer cells and some normal cells, is important for cell growth in NSCLC. Exactly how Tarceva works is not yet fully understood; however, clinical trial results have proven that, in some patients, Tarceva can be effective in both improving patients' survival and slowing or stopping the growth of cancer.