Bjorn Henning Gronberg, MD, PhD, on Extensive-Stage SCLC: Concurrent TRT and Chemoimmunotherapy

So the background of the trial is that after the introduction of immunotherapy, we saw the first advance in the treatment of extensive-stage small cell lung cancer. But still most patients relapse within one to two years and we definitely need better treatment. There were some promising results from an older Dutch trial indicating that consolidation thoracic radiotherapy after chemo alone improved survival, and several smaller preclinical studies indicate that there might be a synergistic effect of combining radiotherapy with immunotherapy. So we combine this and the main objective of the trial was to investigate whether survival is improved if you combine thoracic radiotherapy with chemoimmunotherapy. The study was prematurely closed due to an interim analysis that did not find any indications of an effect and there were also concerns from our safety and data monitoring committee that there were more serious adverse events in the experimental group. Overall, we did not find any signs of prolongation of survival among patients who received TRT and there were also more adverse events, but maybe most concerning there were more treatment related deaths. So overall, we conclude that thoracic radiotherapy should not be routinely given to these patients, but of course should probably still be considered for patients who have symptoms from tumor compression from central airways and so on. Especially since I am, as far as I know, there are only results from another randomized trial that was the German TREASURE trial that was also closed prematurely for the same reasons. This is a little bit surprising considering that quite many retrospective studies are indicating a survival benefit, but due to the results we have from randomized trials, this should probably not be routinely given, at least not until we have results from other ongoing studies investigating the same topic.