VBI Vaccines Inc. today announced that additional biomarker data from the Phase 1/2a clinical study of VBI-1901, the Company's cancer vaccine immunotherapeutic candidate in recurrent glioblastoma (GBM), were presented at the 27th Annual Meeting and Education Day of the Society for Neuro-Oncology.
VBI-1901 is a novel cancer vaccine immunotherapeutic candidate developed using VBI's enveloped virus-like particle (eVLP) technology to target two highly immunogenic cytomegalovirus (CMV) antigens, gB and pp65.
In the limited study arms that assessed high-dose VBI-1901 adjuvanted with granulocyte-macrophage colony-stimulating factor (GM-CSF), two partial tumor responses (PR) were observed in patients.
One patient with a PR remained on the treatment protocol for more than 28 months, reaching survival of at least 32 months as of November 1, 2022.
An additional five patients demonstrated stable disease for a sustained period of time.
All tumor responders (n=7) reached a minimum survival of 12 months
And the median overall survival (mOS) was 12.9 months, comparing favorably to 8-month mOS for monotherapy standard-of-care.
This new data from extensive biomarker panels suggest that normal baseline CD4+/CD8+ T cell ratios, along with boosting of CMV gB-specific antibody responses, were correlated with tumor and clinical responses.
"In an effort to better help address the significant unmet need for patients with recurrent GBM, a particularly devastating cancer, we continue to analyze comprehensive biomarker data from this Phase 1/2a study to identify potentially predictive correlates of response to treatment," said David E. Anderson, Ph.D., VBI's Chief Scientific Officer, in a press release on November 21, 2022.
"We were pleased to see that the previously identified CD4+/CD8+ T cell ratio, a measure of immunological fitness, was associated with tumor responses and encouraging overall survival benefit compared to historical controls."
"We plan to incorporate this learning into the enrollment eligibility criteria in the next stage of development to help enrich potential VBI-1901 responders."
"We look forward to initiating a randomized, controlled evaluation of VBI-1901 in the recurrent setting in early 2023."
Glioblastoma is the most common and aggressive malignant primary brain cancer in adults, says the U.S. NIH. The prognosis remains poor following standard-of-care treatment with surgery, radiotherapy, and chemotherapy.