The AML trial is specifically for post stem cell transplant. Initial treatment is still chemotherapy. MT401 is not being given as a stand alone therapy. It will be given only to patients after they have had a stem cell transplant. Prior to the transplant they more than likely will have gone through chemotherapy already. In the adjuvant arm they can compare to a standard of care (SOC) because the SOC post transplant is just observation.
It looks like they are trying to somewhat mirror the BCM pancreatic trial in that those patients were not given MultiTAA until after chemo. I would imagine they feel this gives them the best shot. Keep in mind they are only running this trial to get a data set that will be large enough to appeal to a BP partner. The future PII trial design will be the one that really matters.