Which of the following is the most common cause of acquired resistance to EGFR TKI therapy?

Q. Which of the following is the most common cause of acquired resistance to EGFR TKI therapy?

A.            Mutation is exon 20 (T790M)

B.            Mutation is exon 21 (T790M)

C.            MET exon 14 skipping mutation

D.            Gain of function mutation in TP533

Answer: Mutation is exon 20 (T790M)