Arbutus Biopharma discontinues AB-161 development, AB-343 coronavirus therapy

Arbutus Biopharma announced pipeline updates including its continued focus on its hepatitis B virus, or HBV, assets, imdusiran as a therapy in a functional cure treatment regimen for patients with chronic hepatitis B virus, as well as its oral PD-L1 inhibitor, AB-101. In addition, the company is discontinuing development of its oral RNA destabilizer, AB-161, due to a pre-clinical toxicology finding not related to peripheral neuropathy. There were no safety issues reported in the healthy subjects that received single doses of AB-161 in the Phase 1 clinical trial. The company is also discontinuing its efforts to identify and develop a coronavirus combination therapy that included AB-343 its Mpro candidate, due to an unfavorable PK profile noted in the IND-enabling studies, and a potential nsp12 polymerase inhibitor. These pipeline changes are expected to extend the company’s cash runway through Q3 2025. The company remains on track to report preliminary data in the fourth quarter of this year from the Phase 2a clinical trial with imdusiran and Vaccitech’s VTP-300 in patients with cHBV. In addition, the company has dosed the first subject in its Phase 1a/1b clinical trial with its oral PD-L1 inhibitor, AB-101, for HBV and expects preliminary data in the first half of 2024.