Future Horizons in Lung Cancer

PDL1 and other biomarkers for selecting patients for immune checkpoint therapies

Dr Mary O'Brien - The Royal Marsden NHS Foundation Trust, London, UK

I’m doing the debate with Professor Gordon McVie on the utility of PD-L1 testing as a selection criteria for treatment; so I’m pro and he’s against it. My arguments to convince the audience will be that testing for any marker has brought us improvements in the selection of patients for treatment that has made real benefits in terms of their survival and has minimised the number of patients that are exposed to futile treatments and also has minimised our chances of throwing away a treatment that in fact has only a little effect but in the right group has a big effect and finally, actually, will curtail costs because these new treatments are going to be very, very expensive. So I will use examples from when we did the first generation of drugs looking at the EGFR receptor mutation and it was only really when we defined the mutation that we started to get the big benefits. That followed on with looking for the ALK-MET translocation, again knowing the target, selecting the patients, giving them their treatment has changed the profile of many patients with lung cancer.

So we are at another landmark. OK, the marker isn’t perfect, it’s not 100% selective, there are a number of variations and all of that is the detail that has to be ironed out. But it’s not a bad start and across all the drugs and all the tumour types we’re showing that selecting patients for this biomarker using whatever kit you like is actually making at least a doubling on the chances of success and that’s real.

Now, of course, the data we have is all advanced disease second line but we’ve just had press releases on the first line data. Now, first line treatments in any cancer is the biggest market, it’s your best chance of curing your patient or giving them a long-term survival and maybe preventing them from ever needing chemotherapy. So the stakes are very, very high on every aspect. We’ve just had two drugs, one didn’t test and the other did test. Which one is the winner? The one that tested. So my joke in all of this is one trial that gets the benefit without using a marker is just something I can’t understand at the minute but all the other trials are saying you should select. So one unselected trial does not make the case, which I think is what Professor McVie will focus on, so I leave you with one swallow does not make a summer but his one positive trial is the swallow.