Vaccitech to Present Positive Final Data at EASL Congress for Phase 1b/2 HBV002 Study in Adults with Chronic Hepatitis B

June 21, 2023 – Clinical Trials –

Oxford, United Kingdom – 21 June 2023 (GLOBE NEWSWIRE) – Vaccitech plc, a clinical-stage biopharmaceutical company engaged in the discovery and development of novel immunotherapeutics for the treatment of autoimmunity, chronic infectious diseases and cancer, will present positive final data from the HBV002 clinical trial at the European Association for the Study of the Liver (EASL) Congress 2023 – The International Liver CongressTM taking place June 21-24 in Vienna, Austria. HBV002 (NCT04778904) is a phase 1b/2a clinical trial of VTP-300 in adults with chronic Hepatitis B (CHB). The data will be presented as a poster at EASL on Saturday, June 24 (Poster ID: SAT-198), by Eleanor Barnes, Professor of Hepatology and Experimental Medicine at Oxford University.

‘An effective immune response is likely to be essential to controlling chronic Hepatitis B,’ said Meg Marshall, Vaccitech√≠s Chief Medical Officer. ‘The durable reductions in HBsAg we saw in this study are exciting because they support the idea that VTP-300 could be a critical component to enhancing rates of functional cure for people with chronic Hepatitis B.’

Meaningful, durable reductions of Hepatitis B Surface Antigen (HBsAg) were seen in all participants with a >0.5 log10 reduction in HBsAg who received VTP-300 alone (Group 2) or in combination with a single administration of low-dose PD-1 inhibitor, nivolumab (Group 3). Two of five patients with baseline HBsAg below 100 IU/mL in Group 3, developed a non-detectable HBsAg level, which continued eight months after last dose. Reductions in HBsAg were most prominent in those with lower baseline HBsAg. Importantly, all participants who received VTP-300 and experienced a >0.5 log10 reduction in HBsAg had durable responses with reductions in HBsAg persisting through to the last measurement eight months post-final dose.

VTP-300, encoding Hepatitis B virus (HBV) genotype C antigens, led to a decline in HBsAg in the majority of people infected with genotypes B and C viruses. In addition, VTP-300-induced T cells showed cross-reactivity to the core antigen from genotypes A to E in ELISpot assays using PBMC from VTP-300-treated healthy subjects and genotype-specific peptides A-E. A robust T cell response was generated against all VTP-300 antigens and was highest in the VTP-300 alone group. In that group, there was a relation between ELISpot responses and HBsAg decline.

‘Three hundred million people are estimated to be chronically infected with HBV worldwide,’ noted Professor Eleanor Barnes. ‘Demonstrating crossreactivity to genotypes B and C in participants, as well as to A-E in healthy subjects, is a promising step to being able to address chronic Hepatitis B infection in as many people as possible.’

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