I have been involved with brain tumors for almost 30 years. For most of that time I believed that a phase 3 randomized controlled trial was the best way to tell if a drug is working. I saw too many cases where a phase 1 or 2 trial had spectacular results and then failed in phase 3. I have always known that phase 3 clinical trials results (even those in a "standard of care" arm) were better than how patients outside a trial did, and I used to think that meant that any trial is better than no trial and perhaps the extra monitoring of patients in a clinical trial helped.
This article explains why trial patients do better and it has nothing to do with being in a trial. It is the entry criteria. The vast majority of Glioblastoma patients are not eligible for clinical trials, and those people do much worse than the patients who are eligible. This also means that the results of a phase 3 trial do not represent how the treatment would work in the general Glioblastoma patient population.
We need to rethink how we test drugs. We absolutely need to track all brain tumor patients as if they are in a trial to see how treatments work on everyone, not just the selected few.