Projections Met or Exceeded For Fourth Consecutive Quarter

BETHESDA, MD, February 23, 2012 — Northwest Biotherapeutics (OTC.BB: NWBO) (NW Bio) today announced that it now has 30 clinical trial sites open and recruiting across the United States in its ongoing Phase 2 clinical trial of DCVax®-L immune therapy for Glioblastoma multiforme (GBM), the most lethal form of brain cancer. The Company reached this milestone ahead of schedule, as the Company had projected to reach it by the end of Q1, 2012. The Company likewise met or exceeded its projections in the three preceding quarters (Q2, Q3 and Q4 of 2011), as previously announced.

The Company plans to continue adding clinical trial sites, and expects to have at least 40 sites open and enrolling by the end of Q2, 2012. The Company will also continue pursuing its programs in Europe. The open and active trial sites are listed on the U.S. Government’s website, www.clinicaltrials.gov, and on NW Bio’s website, www.nwbio.com.

As previously stated, the Company’s progress continues to reflect the growing interest from both physicians and patients, and a growing awareness of the positive data from the Company’s prior clinical trials for GBM brain cancer. In those trials, patients who received DCVax® showed a median survival of 3 years compared with median survival of 14.6 months for patients who received standard of care (surgery, radiation and chemotherapy). Patients who received DCVax®also experienced a substantially longer time to tumor recurrence: a median of 2 years, compared with 6.9 months in patients who received standard of care. DCVax® was well-tolerated, with no toxic side effects.

Linda Powers, CEO of NW Bio, commented that “Together with our recently announced partnership with the American Red Cross, the ongoing expansion of our clinical trial sites is 2 helping to build a broad network to bring DCVax® to patients throughout the country. We are pleased to see the continuing expansion of interest in DCVax® in the medical community.”

About Northwest Biotherapeutics

Northwest Biotherapeutics is a biotechnology company focused on developing immunotherapy products to treat cancers more effectively than current treatments, without toxicities of the kind associated with chemotherapies, and on a cost-effective basis, in both the US and Europe. The Company has a broad platform technology for dendritic cell-based vaccines. The Company’s lead clinical trial is a 240-patient Phase II trial in newly diagnosed Glioblastoma multiforme (“GBM”), the most aggressive and lethal brain cancer. The Company also previously received clearance from the FDA for a 612-patient Phase III trial in prostate cancer, and clearance from the FDA for Phase I trials in multiple other cancers. The Company has also conducted a Phase I/II trial with DCVax® for recurrent metastatic ovarian cancer. For further information about clinical sites and about the Company, please visit the Company’s web site at www.nwbio.com.

Disclaimer

Statements made in this news release that are not historical facts, including statements concerning future treatment of patients with GBM using DCVax® and future clinical trials, are forwardlooking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as “expects,” “believes,” “intends,” and similar expressions are intended to identify forward-looking statements. Actual results may differ materially from those projected in any forward-looking statement. Specifically, there are a number of important factors that could cause actual results to differ materially from those anticipated, such as the Company’s ability to raise additional capital, risks related to the Company’s ability to enroll patients in its clinical trials and complete the trials on a timely basis, the uncertainty of the clinical trials process, uncertainties about the timely performance of third parties, and whether the Company’s products will demonstrate safety and efficacy. Additional information on these and other factors, including Risk Factors, which could affect the Company’s results, is included in its Securities and Exchange Commission (“SEC”) filings. Finally, there may be other factors not mentioned above or included in the Company’s SEC filings that may cause actual results to differ materially from those projected in any forward-looking statement. You should not place undue reliance on any forward-looking statements. 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.