Actually, it's more like 100%, since the trial protocol provides for at least 5 doses and aims for up to 10 doses:
8.7 ADMINISTRATION OF DCVAX-L OR PLACEBO Over the course of the study patients will receive up to 10 DCVax-L or placebo injections at days 0, 10, 20, and at months 2, 4, 8, 12, 18, 24 and 30.
My mother was in the trial. She was not double dosed and there was no way to get a double dose. When her GBM came back she had a second resection. I spoke to her neuroncologist and I spoke to NWBO. It was not possible. Those that were in the placebo received DC Vax after progression and it was made from the original tumor and frozen