Your control arm in a clinical trial can be placebo, standard of care (SOC), watch and wait, or a combination. The FDA has approved first in class medicines in high unmet need populations using ph1, single arm, non-randomized/blinded trials; they have stated recently they will probably do this no longer which is causing a big stir in pharma/biotech space. The DCVAX trial was plagued by many issues. Pseudo-progression of patients being a major one. They had to change the efficacy readout from PFS (time to disease progression) to OS (death) because they could not accurately readout from MRI's if people were getting better due to pseudo-progression. This is probably why the trial was so long.