EHA 2019 | CLL RESONATE-2: Five-year follow-up

So the RESONATE-2 trial was the randomized trial in frontline CLL of ibrutinib versus chlorambucil, and that’s actually the trial the led to the label, the full-length frontline label for ibrutinib. Before that it was only in 17p deleted patients. And that trial was very successful in that the original publication, which was in The New England Journal, showed that there was a very dramatic difference in progression-free survival. And at that time, which had a follow-up of about two to three years, there was not yet any median progression-free survival for ibrutinib, and with chlorambucil it was about 17, 18 months which is about what you would expect, pretty good. So the other interesting thing was that the trial did allow crossover, so the patients that went on to progress on chlorambucil could then go on to ibrutinib, and even with the crossover design ibrutinib still provided a survival advantage.

So now we flash forward to The European Hematology Association meeting and we have the five year follow-up from that trial, and there were some impressive findings. The first is that, with five years of follow-up now, in this frontline population there’s still not even close to a median PFS with ibrutinib, so about 80% of those patients are still on the drug and have not progressed. In fact, in the total population there were only eight patients who progressed on ibrutinib, so this is really phenomenal data. And interestingly, even with the five year follow-up, there still maintains a survival advantage in that population. So we don’t know how long the remissions with frontline ibrutinib are going to be, but we know that at five years we’re not even close to a median, so these are going to be really, really, really durable remissions.