Northwest Biotherapeutics Presents Updated Survival Data from Phase III Trial of DCVax®-L For Glioblastoma Using Individual Patient Level Data in Multiple Independent Analyses

Scientific Presentation at British Neuro-Oncology Annual Meeting Shows Original Analysis of Survival Extension Was Likely Underestimated

BETHESDA, Md., July 8, 2026 /PRNewswire/ -- Northwest Biotherapeutics (OTCQB:NWBO) (the "Company" or "NWBio"), a biotechnology company developing DCVax^® personalized immune therapies for solid tumor cancers, announced 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 randomized 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 (SAP) for the DCVax-L trial had envisioned that IPD-based analyses would be undertaken when access to IPD could be obtained.

Two widely recognized 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.

For further information, please see the presentation slide deck on the Company's website (www.nwbio.com)

"These new PSM and IPW analyses, together with the E Value and Rosenbaum's Gamma sensitivity analyses, provide strong evidence and reinforcement of the survival benefit with DCVax-L treatment, based on my review of the statisticians' analyses," commented Dr. Marnix Bosch. "The key is that all of these analyses, which have taken multiple different approaches and have applied them to multiple ndGBM RCTs, have produced results that are all directionally consistent and all in the same range of magnitude. The statisticians' findings indicate that the median survival benefit reported from the original analysis of the DCVax-L Phase III trial, based on cohort-level data, was likely substantially underestimated."

About Northwest Biotherapeutics

Northwest Biotherapeutics is a biotechnology company focused on developing personalized immunotherapy products that are designed to treat cancers more effectively than current treatments, without toxicities of the kind associated with chemotherapies, and on a cost-effective basis.  The Company has a broad platform technology for DCVax^® dendritic cell-based vaccines. The Company's lead program involves DCVax^®-L treatment for glioblastoma (GBM).  GBM is the most aggressive and lethal form of primary brain cancer, and is an "orphan disease."  The Company has completed a 331-patient Phase III trial of DCVax-L for GBM, presented the results in scientific meetings, published the results in JAMA Oncology and submitted a MAA for commercial approval in the UK.  The MAA is currently undergoing review.  The Company has also developed DCVax^®-Direct for inoperable solid tumor cancers.  It has completed a 40-patient Phase I trial and plans to pursue Phase II trials this year. The Company previously conducted a Phase I/II trial with DCVax-L for advanced ovarian cancer together with the University of Pennsylvania.

Disclaimer

Statements made in this news release that are not historical facts, including statements concerning plans for DCVax^® are forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as "expect," "believe," "intend," "design," "plan," "continue," "may," "will," "anticipate," and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Actual results may differ materially from those projected in any forward-looking statement. Readers should not rely upon forward-looking statements. There are a number of important factors that could cause actual results to differ materially from those anticipated, including, without limitation, risks related to delays or uncertainties in regulatory processes and decisions, risks related to the Company's ability to achieve timely performance of third parties, risks related to whether the Company's products will be viewed as demonstrating safety and efficacy, risks related to the Company's ongoing ability to raise additional capital, and other risks included in the Company's Securities and Exchange Commission ("SEC") filings. Additional information on the foregoing risk factors and other factors, including Risk Factors, which could affect the Company's results, is included in its SEC filings. Finally, there may be other factors not mentioned above or included in the Company's SEC filings that may cause actual plans, results or timelines to differ materially from those projected in any forward-looking statement. The Company assumes no obligation to update any forward-looking statements as a result of new information, future events or developments, except as required by securities laws.

CONTACTS

Northwest Biotherapeutics