McDonald et al showed in 2015 that Methylated tumors had 400% more somatic mutations than Unmethylated tumors
and there is strong published evidence (largely from various checkpoint inhibitor clinical trials, described and referenced extensively in the original white paper) that suggests a 4-fold increase in tumor mutational burden may be clinically meaningful in the context of immunotherapies that are designed to target mutations and other tumor associated antigens.
So, a good immunotherapy in GBM might be expected to increase the mOS difference between Methylated and Unmethylated patients, as was the case in the DCVax-L interim analysis
While Carlo Rago's presentation is very interesting, a correction may be in order. Dr. Rago"s states that based on Linda Liau's 2019 video, he can conservatively estimate that at least 51 of the 331 patients (15%) survived 5(+) years without progression.
However, what I heard in Dr. Liau's video and it matches Sentiment stocks' transcription of the video, seems to indicate that Dr.Liau said that the majority of the approx 93 patients (28.2% of 331) who survived 36(+) months enjoyed a PFS status at that time (36 months). That would mean that at least about 47 post 36 months survivors were still PFS at 36(+) months.