This is a multi-centre study conducted in 52 participants, who will each be administered 2 vaccine injections (IM) on Day 0 and Day 28 as follows:~Group 1: MVA-HBV + MVA-HBV (now closed) Group 2: ChAdOx1-HBV + MVA-HBV Group 3: ChAdOx1-HBV + MVA-HBV + nivolumab (IV infusion) Group 4: ChAdOx1-HBV + nivolumab + MVA-HBV + nivolumab (now closed)~Participants are randomised to treatment as the groups are initiated with a 1:1:1:1 allocation. Version 6.0 of the study protocol has closed Groups 1 and 4 to further randomisation; recruitment will now be in a 1:1 ratio between Groups 2 and 3 only. A sentinel participant is dosed in Group 1, with further participants in Group 1 only being dosed at least 48h later. Group 2 is initiated following a Day 7 safety assessment of the first 6 participants in Group 1. Groups 3 and 4 are initiated following a Day 7 safety assessment of the first 6 participants in Group 2.~The primary objective of the study is to determine the safety and reactogenicity of the treatment regimens; this will be assessed by analysis of the incidence and severity of (serious) adverse events and any changes in laboratory values and vital signs.~The secondary objectives of the study are the determination of the immunogenicity of the ChAdOx1-HBV and MVA-HBV vaccines and the impact of PD-blockade, as well as the effect on HBV markers; these are assessed by measurements of the magnitude and avidity of HBV-specific CD4+ and CD8+ T cells and the magnitude of HBV markers.~Following first vaccination, participants remain in the study for 9 months and attend clinic visits for vaccination and assessments on Days 0, 7, 28, 35 and Months, 3, 6 and 9.
This is an open-label study to determine the safety, tolerability and immunogenicity of ChAdOx1-HBV and MVA-HBV vaccines, with or without nivolumab, in patients with chronic HBV who are virally suppressed with oral anti-viral therapies.