According to Prins, the vaccination is "less effective" when GBM is actively progressing while on SOC treatment. He describes this as the "achilles heel" of any vaccination. If the patients have progressive tumors at the time they begin vaccination (like those rapid progressors in the Info Arm), OR... they were expressing genes known to be immune inhibitors (TGF beta or IL-10), immune responses, or T cell infiltration did NOT happen after vaccination.
Prins said they can get the t cells there and even activated in these patients, but they can't get extended survival in these patients.
He would know how these patients were responding to the vaccination from both the Info Arm and the EAP open label trial where all the rapid progressors go and immediately begin to receive the vaccination.
Now we know from the Info Arm data that the 20 double rapid progressors (those patients that by the time they began treatment, they had double the progression that would have rendered them ineligible to enter the main arm of the trial) showed a 15.3 median OS. And the median OS for rapid progressors is typically between 8.3 to 10.8 months. So a 15.3 median is definitely extending these patients' lives. But with this study linked below, Prins et al actually cured the mice using the combo of the DC Vaccine and the check point inhibitor.
Thus, by generating an immune response in a nonimmunogenic, established tumor — and by activating it with PD-1 mAb blockade — we are able to both generate and maintain effective immunity with therapeutic benefit.
It is possible that, in patients, dual vaccination and PD-1 mAb blockade will not only enhance survival benefit with established tumors, but also decrease the likelihood of GBM recurring.
Maybe a new approach is necessary because she's a dedicated professional. Maybe she'd like to look patients in the eye and tell that there's hope for normal, cancer free life, and not just an pushing back the inevitable by a year or two, or even ten.