Northwest Biotherapeutics (OTCQB:NWBO)(NWBio), a biotechnology company developing DCVax personalised immune therapies for solid tumour cancers, announced on Wednesday that the company's chief technical officer, Dr. Marnix Bosch, presented updated survival data from the Phase III trial of DCVax-L for glioblastoma (GBM) at the 2026 Annual Meeting of the British Neuro-Oncology Society (BNOS).

The updated data included results of multiple different statistical analyses conducted by independent statisticians, using individual patient-level data (IPD), and demonstrated that the survival extension with DCVax-L was likely underestimated in the original analysis of the trial results.

The original analysis of the DCVax-L trial results used cohort-level data to compare the results in DCVax-L patients vs. controls, as the company only had access to cohort-level data for the controls. More recently, the company obtained individual patient data (IPD) from several major randomised controlled trials (RCTs) in newly diagnosed glioblastoma (ndGBM), which enabled more precise matching of the DCVax-L patients and the controls. Notably, the statistical analysis plan for the DCVax-L trial had envisioned that IPD-based analyses would be undertaken when access to IPD could be obtained.

According to Northwest, two widely recognised and rigorous statistical methods were applied by the independent statisticians for the IPD-based analyses: propensity score matching (PSM) and inverse probability weighting (IPW). The PSM analyses of two large RCTs in ndGBM found that the median survival advantage with DCVax-L treatment was 4.9 to 6.3 months, and PSM analysis of a third RCT in ndGBM found 3.4 to 3.7 months survival advantage with DCVax-L. The Hazard Ratios (HRs) ranged from 0.69 to 0.77, and the p values ranged from 0.004 to 0.027. All of these results are substantially greater than the results of the original trial analysis, which found that the median survival advantage with DCVax-L was 2.8 months based on cohort-level data.

The IPW analyses, taking a different approach than the PSM analyses, delivered similar findings: median survival advantage with DCVax-L of 3.4 to 4.3 months.

In addition to conducting the PSM and IPW analyses of known prognostic factors, the statisticians also conducted two forms of sensitivity analyses to check for potential unknown factors which could have confounded or biased the results: E Values and Rosenbaum's Gamma measures. The results of these sensitivity analyses demonstrated that the observed treatment effect with DCVax-L is not attributable to a hidden imbalance between the DCVax-L patients and the controls.