I have recently been diagnosed with Stage IV NSCLC. I have been taking Tarceva since 5/19/05 and just had my "re-staging" this past week (7/1/05). My doctor said that my lung tumor has shrunk approximately 10%! YEAH! I am in that group where Tarceva is suppose to work really well - female, youngish (36 yrs. old), non-smoker with EGFR mutation.
With regards to the 2nd mutation, there is a clinical trial currently in progress for an irreversable EGRF blocker - see web site:
http://www.massgeneral.org/pubaffairs/issues2005/052005Haber
My doctor said this clinical trial is only in Stage 2, but it is evidently a drug that they were actively researching, but abandoned testing once Tarceva came along. Now they are looking at this drug again to stop the 2nd mutations - so there is HOPE!