Vir Biotechnology has dosed the first subject in the Phase II SOLSTICE clinical trial of VIR-2218 and VIR-3434 as monotherapy and together to treat patients with chronic hepatitis D virus (HDV) infection.
The open-label, multicentre trial will assess the safety, tolerability, and efficacy of VIR-2218 and VIR-3434 in adults aged 18 to 69 years with chronic HDV infection who are on nucleot(s)ide reverse transcriptase inhibitor treatment.
Trial subjects will be given multiple, subcutaneous doses of VIR-2218 and VIR-3434, either as a single agent or together, based on the arm for up to 88 weeks.
The proportion of subjects attaining either a ≥ 2log10 decline in HDV ribonucleic acid (RNA) versus baseline, or HDV RNA under the limit of alanine transaminase (ALT) quantification and normalisation at week 24, is the trial’s primary endpoint.
The other primary endpoint is the proportion of subjects having treatment-emergent adverse events and serious adverse events.
Vir anticipates reporting the preliminary findings from the trial next year.
An investigational small interfering RNA (siRNA), VIR-2218 lowers the level of all HBV proteins in vitro.
VIR-3434 is a hepatitis B surface antigen that acts on monoclonal antibodies which can eliminate HBV and HDV virions from the blood. It can also hinder viral entry into liver cells.
Vir Biotechnology clinical research senior vice-president and chronic infection head Carey Hwang said: “Recent research suggests that reducing HDV viremia, by preventing virion formation as well as facilitating virion removal, in conjunction with blocking HDV virion entry into liver cells could be effective in suppressing chronic HDV infection.
“The initiation of SOLSTICE, our first clinical trial in HDV, is an important milestone as we advance our broad therapeutic portfolio for viral hepatitis, which also includes the pursuit of a functional cure for chronic HBV infection.”