Vir Biotechnology to Present New Data from Its Ongoing Phase 2 Chronic Hepatitis Delta and B Trials Today at AASLD’s The Liver Meeting 2023 - Seite 2

Phase 2 MARCH Part B (CHB)

A late-breaking poster presenting new data from the ongoing MARCH Part B trial demonstrates that HBsAg loss rates at the end of treatment (EOT) for the combination of VIR-3434 + VIR-2218 with and without peginterferon alpha (PEG-IFN-α), when given for 24 weeks, are approximately three times higher than the 5.6% EOT rate previously reported for VIR-2218 + PEG-IFN-α. Specifically, at 24 weeks, 15.0% and 14.3% of participants achieved HBsAg loss at EOT for VIR-3434 + VIR-2218 and VIR-2218 + VIR-3434 + PEG-IFN-α, respectively. In addition, anti-HBs antibody titers > 10 mIU/mL at EOT were detected in 52% (11 of 21) of participants in the triple combination of VIR-3434 + VIR-2218 + PEG-IFN-α cohort versus 11% (2 of 18) with VIR-2218 + PEG-IFN-α.

“The higher proportion of participants achieving anti-HBs titers with the addition of VIR-3434 to VIR-2218 and peginterferon alpha strongly suggests that VIR-3434 not only contributes to HBsAg loss through clearance of HBsAg, but also has the ability to reawaken the immune system and generate HBV-specific immunity,” said Edward Gane, M.D., Professor of Medicine at the University of Auckland, New Zealand, and Chief Hepatologist, Transplant Physician and Deputy Director of the New Zealand Liver Transplant Unit at Auckland City Hospital. “This data implies VIR-3434 can function as an immunostimulant.”

Post treatment data will also be presented, showing that two participants with the highest peak anti-HBs titers who received 24 weeks of VIR-3434 + VIR-2218 + PEG-IFN-α maintained HBsAg loss through post-treatment Week 12. Rebound of HBsAg after EOT was observed in all other participants (19 of 21). The Company will continue to follow all participants through post-treatment Week 24 and beyond.

The new MARCH Part B data builds upon the previously reported VIR-2218 + PEG-IFN-α data in which the Company demonstrated the potential for its siRNA VIR-2218 to enhance EOT and post-treatment HBsAg loss rates: 30% of participants receiving up to 48 weeks of combination therapy achieved EOT HBsAg loss and 16% achieved a sustained HBsAg loss 24 weeks after EOT.

“It is important to remember that while these are small participant numbers, this immunologic data is the first evidence that, when part of a combination regimen, our vaccinal antibody VIR-3434 has the potential to play an important role in facilitating a functional cure for patients living with chronic hepatitis B. I am therefore very much looking forward to seeing what will happen when VIR-3434 and VIR-2218 are given, with and without peginterferon alpha, for 48 weeks,” said Pang. “What has been repeatedly observed with peginterferon immunotherapy is that the majority of the benefit occurs after the first 24 weeks of treatment. Thus, we may be seeing just the beginnings of the potential of our regimens.”