Vir Biotechnology reported Wednesday that its monoclonal antibody tobevibart, as a monotherapy and in combination with Alynylam-partnered elebsiran, achieved high rates of virologic response at week 24 in patients with chronic hepatitis delta.
Vir Biotechnology’s monoclonal antibody showed promising response in clearing the most severe form of hepatitis virus from the body in the Phase II SOLSTICE trial. The San Francisco company shared preliminary data on Wednesday and will present more detail at the 2024 Congress of the European Association for the Study of the Liver on Saturday.
In patients with chronic hepatits delta (HDV), Vir tested its investigational monoclonal antibody tobevibart as both a twice-monthly monotherapy and a monthly subcutaneous injection in combination with Alnylam-partnered elebsiran, an investigational small interfering ribonucleic acid.
Among 11 participants in the monotherapy twice-monthly dosing arm, 55% of patients saw a decrease in virus levels and in 18%, or two out of 11, the virus couldn’t be detected. In the combination therapy arm, all patients achieved the lower limit of quantification for virus levels and in over half, or six out of 11 participants, the virus was not detected at all at 24 weeks. No treatment arms reported serious adverse events or events higher than grade 2.
Hepatitis D can infect individuals who already have hepatitis B. Those with both experience a higher risk of liver damage that is irreversible and life-threatening combinations.
“The impressive reduction in HDV RNA observed in the preliminary SOLSTICE trial data surpasses any previous therapy reported to date and highlights the promise of tobevibart and elebsiran in addressing this critical unmet need,” Tarik Asselah, head of the viral hepatitis unit at INSERM UMR1149, France, said in a statement.
Vir said it will now work with regulatory authorities to determine next steps to bring its candidate to market for patients.
The biotech is looking to go toe-to-toe with Gilead Sciences, which has an HDV treatment already approved in Europe. After scooping up bulevirtide in its $1.4 billion buy of Myr GmbH in 2020, Gilead has faced some setbacks in getting the treatment into the U.S. market.
The FDA issued a Complete Response Letter in 2022 to the company’s BLA, citing concerns regarding manufacture and delivery of the daily injection. Gilead’s resubmitted BLA is still pending with the regulator.
Kate Goodwin is a freelance life science writer based in Des Moines, Iowa. She can be reached at kate.goodwin@biospace.com and on LinkedIn.
