Dec. 16, 2013
Northwest Biotherapeutics, Inc. (NASDAQ: NWBO) ("NW Bio"), a biotechnology company developing non-toxic DCVax® personalized immune therapies for solid tumor cancers, today responded to inquiries from shareholders and investors about differences between NW Bio's technology, products and clinical trials and those of a Competitor who recently announced the results of a Phase II clinical trial with a dendritic cell vaccine for Glioblastoma multiforme (GBM). NW Bio described several areas of significant differences.
A dendritic cell vaccine involves two main ingredients: the dendritic cells themselves (master cells of the immune system), and antigens (i.e., biomarker targets) associated with the particular cancer being treated. The antigens are the targets on the cancer that the dendritic cell vaccine mobilizes the immune system to attack. The antigen component of NW Bio's DCVax technology and products is different from the Competitor's in two ways which the Company believes are quite important.
- First, NW Bio's DCVax uses the full set (potentially hundreds) of antigens on the patient's tumor. In contrast, the Competitor uses only six pre-selected antigens -- and actually uses only fragments (peptides) of even these six antigens. NW Bio believes that hitting the full set of antigens makes it harder for the tumor to "escape," and NW Bio has long emphasized this as a key difference between its DCVax technology and the Competitor's technology.
- Second, NW Bio's DCVax uses personalized antigens from the patient's own tumor. This provides assurance that the antigen targets, which DCVax mobilizes the patient's immune system to hit, are actually on that patient's version of the cancer. In contrast, the six antigens used in the Competitor's technology are pre-selected standardized antigens that may or may not be expressed, in whole or in part, on a given patient's version of GBM brain cancer. The scientific literature has established that GBM is highly variable from patient to patient.
NW Bio's DCVax platform technology has been applied in two prior Phase I/II clinical trials for GBM, a small Phase I trial in metastatic ovarian cancer, a Phase I/II trial in late stage prostate cancer, a large number (over 100) prostate cancer patients in an academic setting, and a number of diverse compassionate use cases, over the course of more than ten years of clinical development. The Competitor's technology had only previously been applied in one Phase I trial with 16 patients.
Clinical Trial Differences.
NW Bio is well under way with a 312-patient Phase III clinical trial. The trial has been approved by three separate, highly rigorous regulators: in the US, UK and Germany. The DCVax technology and the Phase III trial have been evaluated by the National Health System (NIHR) in the UK and "adopted" as a nationwide priority in the UK. NW Bio's Phase III trial is robustly designed. If the primary endpoint is met, it is anticipated that this may result in a p value of 0.01 one-sided (0.02 two-sided), with a power of 82%. A two-sided p value of 0.02 is well below (and hence stronger than) the p value of 0.05 which is generally needed for statistical significance. Such a p value would provide a substantial cushion in case the difference in PFS turns out to be less than was projected in determining the statistical powering in the design of the trial.
NW Bio's Phase III trial is also potentially powered for the secondary endpoint of overall survival (OS), and it has an interim analysis devoted solely to reviewing the size of the trial, which can enable increasing the size of the trial if desired. In addition to all these measures, the trial has built-in analyses of specified subsets of the patients in the trial.