Would you re-challenge patients with an EGFR TKI beyond progression if repeated biopsies show redemostration of a sensitizing mutation (exon 19 deletion) and no other resistance mechanisms?   

In a patient who has progressed after initial TKI based therapy and who lack a specific resistance mechanism (for example, a T790M in patients treated with first line TKI), my typical "next line" is chemotherapy (+/- immunotherapy - the IMPower 150 study showed the same hazard ratio for patients wit...