The scientists’ report addresses a few limitations of the...

The scientists’ report addresses a few limitations of the clinical trial, such as it being a single-institution study involving a heterogeneous group of cancer patients who were heavily pre-treated. “Such patients tend to have poor ability to mount an effective antitumor immunity because of tumor- and treatment-induced immunosuppression,” they explain, adding that patients who are less heavily pretreated or have a lower tumor burden have been found to stage a more effective and sustained immune response.

From my lay reading of the document these things stand out:
- The people had all had heavy chemo. Like a minimum of 4 times right which weakens the immune response anyway.
- Giving B-VAX in higher concentrations did not occur/was not tried.

The upshot being that the dosing of the patients was hamstrung to a degree for a range of reasons including those outlined above. There were signs of effectiveness but if the patients were less heavily chemo treated (and possibly dosed more) they expect the response would be improved.

So the results seem encouraging but not amazing.