Vir Biotechnology, Inc. announced that the first participant has been dosed in the Phase 2 STRIVE sub-protocol clinical trial evaluating the safety and efficacy of regimens containing combinations of VIR-3434, VIR-2218, pegylated interferon alpha (PEG-IFNa) and a nucleoside reverse transcriptase inhibitor (NRTI) in hepatitis B virus (HBV) immune-active, treatment-naïve adults. The STRIVE sub-protocol trial is the first to initiate under Vir's new PREVAIL platform trial evaluating VIR-2218 and VIR-3434 with other therapies, including PEG-IFNa and an NRTI, in people at various stages of chronic HBV infection. Initial data from the STRIVE sub-protocol trial are expected in the first half of 2024.

The Company is also enrolling adults who are inactive carriers of HBV in its Phase 2 THRIVE sub-protocol clinical trial. Under the PREVAIL platform trial, the THRIVE sub-protocol trial will evaluate the safety and efficacy of regimens containing VIR-3434 and an NRTI with or without VIR-2218. Initial data from the THRIVE sub-protocol trial are expected in the first half of 2024.

VIR-2218 is an investigational subcutaneously administered small interfering ribonucleic acid (siRNA) that has the potential to stimulate an effective immune response and have direct antiviral activity against HBV and hepatitis D virus (HDV). VIR-3434 is an investigational HBsAg-targeting monoclonal antibody (mAb) engineered to potentially function as a T cell vaccine. VIR-3434 was identified using Vir's proprietary mAb discovery platform that has previously yielded Ebanga and Xevudy as well as VIR-2482, an investigational mAb targeting influenza.

VIR-2218 and VIR-3434 are also being evaluated for the treatment of chronic HBV in adults who are already virally suppressed by an NRTI in the Phase 2 MARCH (Monoclonal Antibody siRNA Combination against Hepatitis B) trial. The initiation of the STRIVE sub-protocol trial is now one of five key combination trials underway as part of Vir's broad HBV clinical program in pursuit of a functional cure.