Ex, you are correct in that the 40 patient phase 1 direct trial did not show overall response rate or partial response. The group with SD stable disease did of course do better.
from the paper:
Evaluation of efficacy
Treatment efficacy was evaluated by CT or MRI studies according to Response Evaluation Criteria in Solid Tumors v. 1.1 (34) or immune response-related criteria (35). Briefly, progressive disease (PD) was defined as a ≥20% increase in the sum of the target lesion's diameters compared with the smallest sum observed during the study, and the absolute sum must increase ≥5 mm. Stable disease (SD) was defined as having insufficient tumor shrinkage to qualify as a partial response (≥30% target lesion diameter reduction), while also having insufficient tumor growth to qualify as PD.
I do recall in some of the earlier presentations by LP and or Bosch showing a case or two that did seem to have substantial tumor shrinkage.
Does make a new trial on direct more challenging to base outcomes on response rate (tumor shrinkage). They did see what imo were some encouraging survival results based on their evaluation criteria. Another excerpt from the paper:
In this study, we showed that aDCs are a safe, feasible treatment option for patients with solid tumors. We also identified specific cytokines that, when secreted by the aDCs, lead to stabilization of disease, resulting in prolonged survival. We showed that (i) T-cell infiltration of the tumor is either induced or enhanced following the therapy; (ii) these T cells are functional CTLs based on in situ cytokine production; (iii) PD-L1 is induced, indicating an immune-related mechanism of action; and (iv) cytokine production (i.e., aDC quality) is correlated with clinical outcome, both in terms of arresting tumor growth (SD) and subsequent survival. Based on these data, it is clear that aDCs are a promising treatment to extend the survival of patients with unresectable, locally advanced, or metastatic solid tumors.
Bosh in a presentation some years back had said they were to publish a follow-up paper on direct which Imo could be quite interesting but as of yet has not happened