The more subgroup data available in the official trial results, the better the chances that later, for other indications, it may be valuable for a general solid tumor approval along the lines of Keytruda, is my guess.
The near future treatment of cancer will be individualized and benefit specific. The more data linking benefit to a specific factor the better, not only for GBM but for all cancers with that marker. Most unmethylated patients who don't respond well to chemo/rad may end up eventually getting DCVax-L much sooner because of this approach. Best wishes.