Question re: How frequent T790m appears in specific mutation groups. - 1264832

greta
Posts:6

What is the frequency of T790m mutations for patients initial diagnosed with exon19 deletions insertions vs exon 20 insertions?
Thank you, Greta

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Dr West
Posts: 4735

I think the only information I've ever seen relates to the frequency of T790M in the setting of acquired resistance to an EGFR TKI in patients with one of the two common activating mutations, which are an exon 19 deletion or an L858R substitution on exon 21. I don't think there have been studies of any meaningful scale looking at T790M for rare mutations, as these don't have anything like the same consistent 60-75% response rate seen with the exon 19 or 21 mutations that account for 88-90% of the EGFR mutations out there.

-Dr. West