Tarceva - 1264922

sherilyn1hansen
Posts:4

What is the name of the blood test to see if K-RAS mutation can be affected by Tarceva in an individual?

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JimC
Posts: 2753

Hi Sherilyn,

You're probably referring to the Veristrat test from Biodesix. Here are a couple of discussions of the test:

http://cancergrace.org/lung/2012/10/05/veristrat/
http://cancergrace.org/lung/2013/06/12/prose-trial-veristrat/

A year ago, after the PROSE trial results were presented at ASCO 2013, Dr. West expressed this opinion:

"I think that the Biodesix test doesn’t really answer a question I consider to be that helpful. It essentially asks “should I not even bother with an EGFR tyrosine kinase inhibitor like Tarceva?” It doesn’t say that doing Tarceva (erlotinib) is a better idea than chemo, and it essentially can only say it’s a worse idea than second line chemo in some patients. There’s now a growing amount of evidence to say that it’s arguably best to give chemo over Tarceva as second line therapy to anyone who doesn’t have an activating EGFR mutation, so if you follow that strategy, the only clear value of the Veristrat test is to say whether Tarceva isn’t even worth trying later. If you’re going to decide to not even take Tarceva if the Veristrat test comes back as poor, I think the test makes sense. But most of my patients aren’t eager to eliminate an FDA approved option that might help and will almost always be covered as a third line agent for NSCLC, so I don’t see how Veristrat provides an actionable answer to any question I’d commonly ask in my clinic patients." - http://cancergrace.org/topic/asco-2013-video-can-we-predict-response-to…

JimC
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Dr West
Posts: 4735

I agree with what has been said, and I would just clarify that the presence of a K-RAS mutation does not mean that Tarceva (erlotinib) won't be helpful. The people with a K-RAS mutation have a low probability of significant tumor shrinkage, but when you look at populations of people with K-RAS mutation and compare what happens when half get Tarceva and half get a placebo, they show the same survival benefit of about 6-8 weeks on average as that seen in people who don't have a K-RAS mutation and also don't have an EGFR mutation.

Those who say that people with a K-RAS mutation get no benefit from Tarceva are incorrect.

-Dr. West

Dr West
Posts: 4735

I agree with what has been said, and I would just clarify that the presence of a K-RAS mutation does not mean that Tarceva (erlotinib) won't be helpful. The people with a K-RAS mutation have a low probability of significant tumor shrinkage, but when you look at populations of people with K-RAS mutation and compare what happens when half get Tarceva and half get a placebo, they show the same survival benefit of about 6-8 weeks on average as that seen in people who don't have a K-RAS mutation and also don't have an EGFR mutation.

Those who say that people with a K-RAS mutation get no benefit from Tarceva are incorrect.

-Dr. West