Arbutus Biopharma Corporation (NASDAQ:ABUS), a clinical-stage biopharmaceutical company leveraging its extensive virology expertise to develop novel therapeutics that target specific viral diseases, today announced that while its partner, Assembly Biosciences, has decided to discontinue development of its investigational hepatitis B virus core inhibitor candidate vebicorvir (VBR), it plans, in consultation with Assembly Biosciences, to continue dosing patients in the Phase 2a triple combination clinical trial evaluating its proprietary RNAi therapeutic, AB-729, VBR and nucleos(t)ide analogue (NA) therapy for the treatment of patients with chronic HBV infection (cHBV). Preliminary data from the trial are expected in the second half of 2022.
William Collier, President and Chief Executive Officer of Arbutus, commented, “While we respect Assembly’s decision to discontinue clinical development of VBR, we believe that it is premature to make any conclusions about any results in this triple combination clinical trial. We intend, in collaboration with Assembly, to continue the clinical trial in order to fully and accurately assess the results. The results from this trial coupled with the additional data we anticipate collecting from our capsid inhibitor program will help inform our go-forward combination strategy in the development of cHBV treatments.”
Mr. Collier added, “In addition, we continue to believe that AB-729 is positioned to become a cornerstone agent in potential curative combination treatments for cHBV.”
The randomized, multi-center, open-label Phase 2a clinical trial was designed to enroll approximately 60 virologically-suppressed patients with HBeAg negative chronic HBV to evaluate the safety, pharmacokinetics, and antiviral activity of the triple combination of vebicorvir, AB-729 and an NA compared to the double combinations of vebicorvir with an NA and AB-729 with an NA. Patients are dosed for 48 weeks with vebicorvir (300 mg orally once daily) and AB-729 (60 mg every 8 weeks), with a 48-week follow-up period. The primary objective of the trial is to evaluate the safety and tolerability of the triple combination, while secondary objectives of the trial include evaluating the effect of the triple combination in reducing HBV viral biomarkers such as HBV DNA, HBV pgRNA and HBsAg.