HBsAg and HBV DNA remain at low levels with no evidence of clinical relapse up to 44 weeks after discontinuing AB-729 and NA therapy
Preclinical data suggest that AB-101, an oral PD-L1 inhibitor, in combination with an RNAi, may provide enhanced HBV immune response
Data to be presented as poster presentations
Additional safety findings lead to discontinuation of AB-836 development
Conference call and webcast scheduled for Friday, November 4th at 8:45 AM ET
WARMINSTER, Pa., Nov. 01, 2022 (GLOBE NEWSWIRE) -- 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 data from i) two separate clinical trials evaluating its RNAi therapeutic, AB-729, in a Phase 1a/1b clinical trial (AB-729-001) and in a combination Phase 2a clinical trial with a capsid inhibitor, and ii) a preclinical study of its oral PD-L1 inhibitor, AB-101. All of the data will be presented as poster presentations at AASLD – The Liver Meeting being held in Washington, DC, November 4-8, 2022.
“Based on the compilation of safety and efficacy data achieved to-date, we are confident in AB-729’s potential role as a cornerstone agent in a curative combination treatment for chronic hepatitis B virus infection (cHBV), said William Collier, Arbutus’ President and Chief Executive Officer. “We believe AB-729 is the only RNAi therapeutic in development for hepatitis B virus that has clinically shown its ability to suppress HBV DNA, reduce HBsAg and immunologically control HBV – three pillars that we consider to be key to developing a functional cure for HBV.”
AB-729-001 Clinical Trial Data In the AB-729-001 clinical trial, patients with cHBV who completed 48 weeks of treatment with AB-729, and 24 weeks later met protocol-defined criteria to also stop nucleos(t)ide analogue (NA) therapy, were evaluated during an extended follow-up period to assess HBV biomarkers and ALT levels. Nine patients entered the follow-up period, currently ranging from 12 to 44 weeks, after stopping all therapies.
Select key findings:
- No evidence of clinical/biochemical relapse has been detected in the nine patients who have discontinued AB-729 and NA therapy.
- HBsAg remains at 1.05 to 2.35 log10 below pre-trial levels in all nine patients.
- Three patients experienced transient HBV DNA elevations that spontaneously resolved without intervention, which further supports AB-729's potential for immunological control.
- One patient restarted NA therapy at the investigator’s request after the week 20 visit; no ALT elevation or safety signals were observed.
- Eight patients remain off NA therapy and are continuing to be followed for an additional two years to monitor for sustained viral response and functional cure.
Dr. Gaston Picchio, Chief Development Officer of Arbutus Biopharma, stated, “I remain impressed with the longer follow up data we generated from our AB-729-001 trial. The data continues to demonstrate that AB-729 is capable of achieving long-lasting control of HBV biomarker levels after discontinuation of nucleoside therapy, most likely as a result of AB-729-induced HBV-specific immunological control. Based on the attributes of AB-729 that we have seen thus far, I believe that AB-729 will be a major contributor to future HBV curative regimens.”
In the same trial, a cohort of seven HBeAg positive patients who received 90 mg of AB-729 every 8 weeks (Cohort K) was also assessed. All patients in Cohort K had HBsAg levels of