The claim DCVax-L works is based on confounded OS data. Most of the patients received multiple doses of DCVax-L which biased the whole trial. The external comparators were from "well-controlled" clinical trials that used standard dosing, while DCVax-L trial had the benefit of most of the participants getting mulitple doses that confounded the data, biasing it in favor the DCVax-L.
No opinion is a fact clearly shown in the protocol (crossover) and stated in NWBO's SEC filing -- confounded OS data.