Replies to post #642599 on NorthWest Biotherapeutics Inc (NWBO)

[biosectinvestor]

DCVax Direct was a safety trial (ORR was not a primary measure) and extended survival for patients destined otherwise to hospice care and with metastatic cancers for which only one could be injected.

Primary Outcome Measures
Outcome Measure Measure Description Time Frame
Number of patients with adverse events 6 months

The short noise about this trial is nonsense. Direct appears to have spectacular potential to treat virtually any kind of solid tumor in its location and extend survival.

ORR was not the primary measure and is not listed. The primary measure is safety. Survival is among the secondary measures. It performed very well on that measure, but there was not a placebo because this was a safety trial only, for patients that had exhausted all standard treatment options, various amounts of cells were injected for safety across a variety of different cancers and tumor types, but only into one tumor.

So it was not intended to be a measure for ORR.

That’s the ridiculous thing about shorts. They make up stuff and just throw it out there expecting retail to have no idea and to just assume what they said makes sense. Everyone has heard of ORR, so they must know what they are talking about when that is far from the case.

https://www.fiercepharma.com/vaccines/dcvax-direct-trial-update-indicates-further-positive-responses-3-case-studies-show-no-live

BETHESDA, Md., June 11, 2014 /PRNewswire/ -- Northwest Biotherapeutics (NASDAQ: NWBO) (NW Bio), a biotechnology company developing DCVax® personalized immune therapies for solid tumor cancers, announced today that, in the ongoing Phase I/II clinical trial of DCVax-Direct for all types of inoperable solid tumors, all 9 out of 9 patients who have received 4 of the 6 planned injections are showing tumor cell death, tumor shrinkage, substantial immune cell accumulation in their tumors and/or stabilization (i.e., stopping the progression) of their advanced cancer. In addition, in 3 of these 9 patients, biopsies now show no live tumor cells in the injected tumor.

https://www.prnewswire.com/news-releases/nw-bio-presents-further-dcvax-direct-phase-i-trial-information-on-individual-patient-survival-at-ny-cancer-immunotherapy-conference-300336496.html

Published Results: https://aacrjournals.org/clincancerres/article/24/16/3845/277824/Cytokines-Produced-by-Dendritic-Cells-Administered

With respect to the efficacy of the aDCs, biopsies of injected tumors showed increased necrosis and infiltration of lymphocytes, including CD4+ helper cells and CD8+ killer cells. In individual cases, we observed immune reactivity with both rapid and delayed infiltration of T cells in patient biopsies and extensive necrosis. These observations preceded a demonstrable reduction in tumor size (Supplementary Fig. S2). Studies have shown that increased infiltration and accumulation of certain types of T cells, such as stromal lymphocytes and CTLs, in tumors are strongly correlated with improved outcomes in several solid tumors (44–46). In addition, PD-L1 was upregulated in 19 of 25 tumors tested, and this upregulation likely reflects the tumor response to immune activation, particularly because tumor biopsies that tested positive for T cells were more likely to have increased PD-L1 expression. PD-L1 is a coinhibitory molecule elicited during lymphocyte infiltration that downregulates T-cell activity to control excessive immune reactions, and tumors use it to evade immune responses (4, 10). Given that our PD-L1 data are from biopsied tumors, the emergence of PD-L1 expression may serve as a marker of successful antitumor immune response induction. Nevertheless, it is possible that the induced immune responses are suppressed by this immune checkpoint and that the addition of a checkpoint blockade following DC therapy may further enhance efficacy. Overall, these results provide evidence that aDCs stimulate an effective T-cell response in solid tumors.
For the aDC treatment to be effective, it should also improve patient outcomes. We hypothesized that the survival mechanism was related to DC potency, as measured by the cytokines secreted by the aDCs. Therefore, we assessed cytokine levels of the aDCs prior to injecting them into the tumors. We observed that IL12p40 was significantly associated with survival. IL12p40 is one subunit of the heterodimeric IL12 complex, also called IL12p70. IL12 is known to stimulate natural killer cells and mature T cells. It is also known to help convert TH2 cells to TH1 cells that have antitumor activity (47). Thus, IL12-producing aDCs are ideal for an effective DC vaccine. We used IL12p40 as a marker of IL12 activity because the gene expression of IL12p35, the other IL12p70 subunit, is lower compared with that of IL12p40 (48). The relatively short activation time of the aDCs was not sufficient for cells to make substantial quantities of IL12p70 complex before harvesting cells, preventing us from exploring the associations between IL12p70 and survival.
IL8 secretion was also associated with survival. Specifically, high IL8 secretion showed significantly higher overall survival. IL8 is largely considered to be negatively associated with cancer, and retention of i.t. DCs through IL8 has been demonstrated (49). IL8 promotes angiogenesis, cell proliferation, and cell survival; however, it also promotes infiltration of immune cells into the tumor microenvironment (50), does not disrupt the ability of DCs to stimulate T cells, and may attract and retain neutrophils when secreted by DCs (4, 49). In the case of BCG immunotherapy, IL8 was associated with the development of an antitumor immune response (51). It seems possible that the localized application of IL8-producing aDCs stimulated infiltration of immune cells into the tumor.
The regression model indicated that the combination of IL8 and IL12p40 was positively associated with survival. To date, the literature is conflicted on whether cytokines, such as IL8, are immunosuppressive or whether they are beneficial by affecting the tumor microenvironment or playing a role in recruiting inflammatory cells. Our positive association with survival indicates that the combination of IL8 and IL12p40 (and possibly other cytokines), rather than individual cytokines, may be key for improved survival. It seems likely that these cytokines play multiple roles in the complex interactions between the tumor and immune system and that the overall effect is beneficial. It is also possible that these molecules solely serve as sensitive markers of overall aDC quality and potency. The observed associations between patient baseline parameters and cytokine production (i.e., aDC quality) suggest that factors, such as SLD and ALC, may predispose patients toward greater benefit from DC-based therapies, although the R2 values suggest that these baseline parameters only explain up to 25% of the variation in cytokine levels. This possibility deserves further attention in subsequent trials with more homogeneous patient populations and will be the subject of future investigations.
IL8 and IL12 are known to play a role in the efficacy of i.t.-administered DCs. Several mouse and human studies evaluated the efficacy of i.t.-administered autologous DCs that were transfected to constitutively express IL12, presuming they would elicit a stronger immune response. Mice with B16 melanoma treated i.t. with IL12-transfected DCs lived significantly longer than those treated with unmodified or GFP-modified DCs. Analysis of mouse spleen cells showed they were sensitized to generate CTLs (52). I.t. administration of IL12-transfected DCs in mice with liver tumors significantly reduced tumor burden (based on liver weight). Further, mice who had previously been treated with IL12-transfected DCs showed sustained immunity when challenged a second time with CMS4 tumor cells (53). In humans with metastatic gastrointestinal carcinomas, IL12-transfected DCs injected i.t. were safe, but the response was limited (54). A study investigating the limited response observed in humans found that IL12-transfected DCs administered i.t. stayed in tumors due to IL8 expression by tumor cells (55). Further investigations showed that IL8 affects DC migration in tumors, but does not affect T-cell stimulation (49). However, this barrier is not insurmountable (56). Nishioka and colleagues (57) showed that IL12-transfected DCs injected i.t. i.t. were capable of migrating to the draining lymph in mice. Similarly, we observed decreased tumor size in distant lesions (Supplementary Fig. S2), indicating that the i.t.-administered aDCs could be reaching the lymph. It seems likely that coupling aDCs with strategies to enhance migration to the lymph may be an effective means to improve aDC efficacy.
To evaluate clinical activity of antitumor vaccines, we must consider parameters other than tumor response criteria, as those may not be adequate or appropriate given the mode of action of these agents. In some cases, cancer immunotherapy may not show an apparent treatment effect, but still have an effect on survival (58). One example is the failed trial for tremelimumab. This trial was canceled due to futility, but later analysis revealed a survival benefit (59). Further, sipuleucel-T, the first FDA-approved cancer vaccine, was approved based on improvements in overall survival (60). In our study, survival analysis of the aDC-treated patients showed that SD at week 8 was significantly correlated with survival. These data suggest that if the tumor can be stabilized by aDCs, then the odds of progression-free survival significantly increase, indicating clinical activity by aDCs. Based on this result, we investigated what cytokines were associated with SD at week 8. Analysis of the cytokine levels showed that TNFa was positively associated with SD at week 8. TNFa is a well-characterized cytokine extensively associated with upregulating the immune response, including DC maturation and T-cell priming, proliferation, and recruitment (61, 62). Human trials have shown that isolated limb perfusion of TNFa can be used to treat locally advanced soft-tissue sarcomas (63). In addition, TNFa has been shown to be critical for antitumor immune responses in mice (61). Our observed positive association between TNFa and efficacy outcomes is consistent with these results.
There were several limitations of this trial. First, this trial was primarily a safety study. The trial was conducted over a limited time frame, and we collected limited biopsy material. Therefore, we could not investigate the mechanism of action by aDCs. Some avenues for future research include looking at clinical activity with respect to PD-L1 and IDO expression; staining for cells that might be recruited by aDCs, such as tumor-infiltrating DCs and Tregs (CD4+/Foxp3+ cells); and performing more extensive chemokine profiling, including CCL5 and CXCL9-11. Second, while the quality of the aDCs was checked prior to patient administration, the aDC release criteria used for the trial may need to be expanded to identify incompletely differentiated aDCs. Third, while there are clear correlations between the quality of the cell product and outcomes, they cannot completely explain variations in clinical outcomes; thus, there are exceptions at the individual patient level. Cancer is a multifactorial disease, and other factors could have a substantial effect on clinical outcomes. However, given the explosive expansion of clinical cell products approved or in the pipeline for regulatory approval, it is clear that cell product quality, in the form of cytokine levels, should be considered as part of trial design and analysis and product distribution. Additional studies in the pipeline include more fully characterizing efficacy parameters, injecting multiple tumors, and biopsying distant tumors. Several of these topics are currently planned in the phase II portion of this trial.
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.

Clinical Trial Program Update: Presentation by Dr. Marnix Bosch at ASCO 2019:
https://vimeo.com/340029244

Thanks for giving me the opportunity to present information thoroughly. I always love it when you shorts go off superficially and it offers the opportunity to present something more comprehensive.