VBI Vaccines Reports New Tumor Response Data from Phase 2b Study of VBI-1901 in Recurrent Glioblastoma

VBI Vaccines Inc. has unveiled promising interim results from its Phase 2b study of VBI-1901, an immunotherapeutic cancer vaccine candidate for recurrent glioblastoma (rGBM). As of May 15, 2024, notable tumor response data has been observed among patients treated with VBI-1901, which will be presented at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting.

The study includes two arms: one receiving VBI-1901 combined with Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) and the other receiving standard-of-care therapy with either Carmustine or Lomustine. In the VBI-1901 arm, 11 patients were randomized, and seven had available tumor response data. Among these, one patient exhibited a partial tumor response (PR) with a significant 67% tumor size reduction by week six after two doses. Additionally, two patients showed stable disease (SD). The disease control rate (DCR) for this cohort stands at 43% (three out of seven patients).

Conversely, the control arm, which included 12 patients, showed no tumor responses among the six evaluated. Five patients experienced tumor growth ranging between two to eight times the baseline size and were subsequently removed from the study protocol. This emphasizes the limited efficacy of existing treatments for rGBM.

David E. Anderson, Ph.D., Chief Scientific Officer of VBI, highlighted the encouraging nature of these interim results and expressed optimism about potential clinical and survival benefits. He stressed that current treatments for recurrent GBM patients are largely ineffective, and the early data showing a 43% disease control rate with VBI-1901 is promising. Similarly, Jeff Baxter, VBI’s President and CEO, underscored the significance of these findings and anticipated further data by the end of 2024, which could prompt discussions with the FDA regarding accelerated approval pathways under VBI-1901’s Fast Track and Orphan Drug Designations.

The Phase 2b study aims to enroll up to 60 patients and is designed to evaluate overall survival, tumor response rates, safety, and tolerability of VBI-1901 in rGBM patients. This study is randomized, controlled, and open-label, involving patients with first recurrent GBM. The patients are divided into two groups: one receiving intradermal VBI-1901 with GM-CSF every four weeks and the other receiving standard-of-care therapy every six weeks until disease progression or intolerable toxicity.

The study outcomes are crucial as they include safety and tolerability, overall survival, tumor response rates, progression-free survival, immunologic responses, reduction in corticosteroid use, and changes in quality of life compared to baseline. VBI-1901 has the potential to address a significant unmet need in rGBM treatment, where the median overall survival is currently around eight months.

Previously, in the Phase 1/2a study of VBI-1901, a 44% disease control rate was observed, leading to clinical improvements in overall survival. The median overall survival achieved was 12.9 months, substantially higher than the 8-month benchmark for standard chemotherapy treatments.

GBM, a highly aggressive brain tumor, sees approximately 12,000 new cases annually in the U.S. alone. The standard treatment involves surgical resection followed by radiation and chemotherapy, but the prognosis remains poor. VBI-1901 leverages VBI’s enveloped virus-like particle (eVLP) technology to target cytomegalovirus (CMV) antigens, potentially triggering a robust immune response against GBM.

With the FDA granting Fast Track and Orphan Drug Designations to VBI-1901, VBI Vaccines Inc. continues to advance towards providing new therapeutic options for combating aggressive cancers like glioblastoma, aiming to improve the lives of patients and their families.