Arbutus Biopharma completes enrollment in Phase 2 trial with AB-729, NA therapy

Arbutus Biopharma announced preliminary data from the AB-729 lead-in portion of its Phase 2a clinical trial combining AB-729 with nucleos(t)ide analogue therapy and Peginterferon alfa-2a. The data reinforces AB-729’s surface antigen reducing-capacity, while continuing to exhibit a generally safe and well-tolerated profile in patients with chronic Hepatitis B virus. Given that only a few patients are in the early weeks of the IFN phase of the clinical trial, the Company intends to provide additional updated data in the first half of next year which will include preliminary results of the IFN portion of the trial. Enrollment is complete in the clinical trial with 43 patients having received at least one dose of AB-729. For the first 15 patients who reached week 16 of treatment and received two doses of AB-729 plus NA therapy, the mean HBsAg decline was 1.51 log, comparable to the decline observed at the same timepoint in the completed Phase 1b clinical trial AB-729-001. As the trial progresses, patients will be randomized into various treatment arms which include the combination of AB-729, NA therapy and short courses of IFN for either 12 or 24 weeks. The randomized, open label, multicenter Phase 2a proof-of-concept clinical trial is designed to investigate the safety and antiviral activity of AB-729 in combination with ongoing NA therapy and short courses of IFN. After completion of the assigned IFN treatment period, all patients will remain on NA therapy for an additional 24-weeks and will then discontinue NA treatment provided they meet pre-defined stopping criteria. Patients who stop NA therapy will enter an intensive follow-up period of 48 weeks.