Arbutus Biopharma Corporation has presented preliminary data from an ongoing Phase IIa trial of RNA interference (RNAi) therapy (AB-729), nucleos(t)ide analogue (NA), and pegylated interferon alfa-2a (IFN) in patients with chronic hepatitis B virus (cHBV) at the European Association for the Study of the Liver (EASL) Congress 2023.
The data from the randomised, open-label, multicentre Phase II trial (NCT04980482) showed a reduction in hepatitis B surface antigen (HBsAg). However, no patient showed sustained loss of circulating HBsAg, which is associated with improved clinical outcomes.
A total of 43 patients were administered - AB-729 every eight weeks, along with 24 weeks of NA. This was followed by NA and IFN for 12 or 24 weeks in all patients, with the addition of AB-749 in half of the patients.
Of the 41 patients, 38 had HBsAg levels of less than 100IU/ml, indicating a decreased risk of disease deterioration.
The AB-729 monotherapy and combination therapy were well tolerated, although IFN doses were modified in five patients.
Two Phase II trials (NCT04847440 and NCT04820686) for AB-729 combination therapy in patients with cHBV have been terminated thus far.
According to GlobalData analysis, the current HBV market is dominated by NA for the long-term treatment of cHBV, with Gilead Science’s Vemlidy (tenofovir alafenamide) being the current market leader. RNAi therapies make up only a small portion of the HBV pipeline, with existing and future players focusing on small molecules (such as NA).
GlobalData is the parent company of Clinical Trials Arena.
