EGFR exon 18. Did you get afatinib (gilotrif) or erlotinib (tarceva)?

[Kwally3]

Hey,

my dad is stage iv nsclc adenocarcinoma with EGFR exon 18 mutations (G719S and E709A). Dr just prescribed erlotinib (tarceva) today. But, some papers I am reading are suggesting afatinib (gilotrif) is better? I am reaching out to dr when she is back from conference next Wednesday but wanted your guys’ thoughts.

https://www.lungcancerjournal.info/article/S0169-5002(18)30645-7/fulltext

UPDATE:
Dr emailed. essentially saying that topic is currently highly controversial. her message below. I'm glad it wasn't a concern.

"You ask excellent questions.  This is a very controversial area in lung cancer treatment right now.  Your father has a relatively uncommon EGFR mutation, so we don’t have large numbers to base our treatment on.

What we know about the G719S mutation is that, at least in cell lines and in case reports of patients, osimertinib does not seem to work very well against this particular mutation (and from what we know, even though your father has two different EGFR mutations, targeting G719S seems to be the most important).  Erlotinib, gefitinib and afatinib all seem very active against this mutation (in fact, a very similar mutation G719C, was described in the first paper detailing response to gefitinib -https://www.nejm.org/doi/full/10.1056/NEJMoa040938).  Though the two papers you describe suggest that afatinib may be better, the data out there is mixed, and in clinical trials this mutation does seem sensitive to both 1st and 2nd generation inhibitors.  Also afatinib comes with much more toxicity, and I find it’s pretty rare for people to tolerate the full dose.

 

Basically – since there’s no super strong evidence that one is better than the other, I tend to select the medication that is better tolerated, and I think that’s erlotinib.  Definitely happy to discuss further – I feel that either drug would be a very reasonable option for him."

[Neverstopfighting]

Kwally,

It seems your dad has a great and understanding doctor.  You should feel lucky/blessed to have someone who 1) responds to you directly via email and 2) is willing to discuss you options with such an opened mind.  

Its also great you are taking such initiative and again, being your dad's advocate.  The doctors know that you will not blinding listen to everything they recommend.  

Nice work,

Joe