My brother's lung cancer has progressed after 1st line chemo and Avastin maintenance. So we are considering options: standard 2nd line chemo, pdl1 trial pending results of test for expression, or targeted therapy if he has a marker.
I received a copy of my brother's next generation sequencing report based off a biopsy from a few weeks ago. It lists EGFR D770_N771insG and ERBB3 amplification. Afatinib is listed next to both as an FDA approved therapy. However, when I read the fine print of the report and search the internet, this type of EGFR has EXON 20 insertions which in general are shown to be less sensitive to reversible EGFR inhibitors than the classic EXON 19 and 21. So my questions:
1. Why would Afatinib be listed as an option if it really isn't? It seems really odd. Does it have something to do with the ERBB3 amplification? Or his particular insertion? Is there something special perhaps regarding the insertion number and the ERBB3 amplification in combination? His doctor is of the opinion that Afatinib is really not an option.
2. Does it make sense to talk to an expert in this area such as Dr. Ross Camidge out of Univ of Colorado because he led trials with Afatinib? Perhaps he has seen this particular insertion first hand.
3. I've read nearly all of the posts on here regarding EXON 20. They lead me to believe that we should just consider him EGFR Wild for all intents and purposes. But I don't want to leave anything unturned if we are misunderstanding something. Is it time to move on and pray for the PDL1 lottery to hit?