VBI Vaccines Inc. announced that additional biomarker data from the Phase 1/2a study of VBI-1901, the company's cancer vaccine immunotherapeutic candidate, in recurrent glioblastoma (GBM) patients, were highlighted in a poster presentation at the 28th Annual Meeting and Education Day of the Society for Neuro-Oncology (SNO), held on November 17, 2023. New proof-of-mechanism data demonstrated that vaccination with VBI-1901 was associated with T-cell activation capable of trafficking across the blood-brain barrier to the tumor microenvironment, an area which is known to be highly immunosuppressive and difficult to infiltrate. The additional peripheral biomarker data assessed levels of C4G­ a protein fragment produced when cytotoxic T-cells, or killer T-cells, migrate into and throughout the tumor microenvironment ­ high baseline levels of which have been associated with longer overall survival in studies conducted in metastatic melanoma patients.

After vaccination with VBI-1901 in the Phase 1/2a study in recurrent GBM patients, the data showed there were higher blood/plasma levels of C4G in patients who achieved partial tumor responses than in patients with stable or progressive disease. Additionally, higher levels of C4G after vaccination with VBI-1901 have been associated with longer progression-free survival. Data Highlights from Phase 1/2a Study Data in Recurrent GBM Patients- VBI-1901 10µg + GM-CSF Study Arms (n=16): 44% disease control rate achieved (n=7/16) ­ disease control rate is defined as stable disease (SD) + partial tumor response (PR) + complete tumor response (CR); 2 PRs were observed ­ 1 patient was on treatment for more than 28 months (2.33 years), surviving at least 40 months (3.33 years) as of August 1, 2023, with a maximum tumor reduction of 93% relative to baseline; 5 additional patients demonstrated SD for a sustained period of time; All patients with a tumor response (PR or SD) (n=7/16) reached a minimum survival of 12 months; Median overall survival (mOS) was 12.9 months, comparing favorably to 8-month mOS for monotherapy standard-of-care.

Ongoing Phase 2b Study Design in Recurrent GBM Patients: Multi-center, randomized, controlled, open-label study in up to 60 patients with first recurrent GBM; Patients will be randomized in a 1:1 ratio across two study arms: Intradermal VBI-1901 + GM-CSF: 10 µg dose every 4 weeks until clinical disease progression; Active comparator: monotherapy standard-of-care ­ either intravenous carmustine or oral lomustine, every 6 weeks until disease progression or intolerable toxicity. Endpoints include: Safety and tolerability; Overall survival (OS) ­ median and overall; Tumor response rate (TRR); Progression-free survival (PFS); Immunologic responses; Reduction in corticosteroid use relative to baseline; Change in quality of life compared to baseline. The U.S. Food and Drug Administration (FDA) has considered demonstration of a statistically significant improvement in overall survival relative to a randomized control arm to be clinically significant and has recognized this as criteria to support the approval of new oncology drugs.