Biopharmaceutical company VBI Vaccines has revealed interim data from its Phase II study evaluating the combination of VBI-2601, VBI’s HBV immunotherapeutic candidate, and BRII-835, an HBV-targeting siRNA candidate, in chronically infected hepatitis B (HBV) patients.
The data demonstrate that the combination therapy was generally well-tolerated, restored strong anti-HBsAg antibody responses, and led to improved HBsAg-specific T cell responses, when compared to BRII-835 alone.
Notably, in two participants who received the combination therapy, maximum reductions in HBsAg to an undetectable level or to the lower limit of quantification (LLOQ) were achieved by Week 40, which were associated with robust HBV-specific antibody and T-cell responses.
Dr Francisco Diaz-Mitoma, VBI’s Chief Medical Officer, commented: “Numerous studies have assessed the potential of siRNA candidates in hundreds of chronically infected HBV patients, but this is the first time we’ve seen data from the combination of an HBV siRNA with an HBV-specific immunomodulator.
“Consistent with the known mechanism of action of VBI-2601 and its inclusion of the pre-S1 and pre-S2 antigens in addition to the S antigen, these interim data indicate that VBI-2601 may be able to break tolerance to the S antigen, achieving immune restoration.”
The interim data was shared in an oral presentation at the 32nd Annual Conference of the Asian Pacific Association for the Study of the Liver (APASL) taking place in Taipei, Taiwan.