Arbutus Biopharma Corporation (NASDAQ: ABUS) announced that the U.S. Food and Drug Administration has lifted a clinical hold on the Investigational New Drug application for AB-101, an oral PD-L1 inhibitor being developed for chronic hepatitis B virus infection. The company said it is evaluating next steps for continued development of the drug.

AB-101 is designed to activate patients' hepatitis B virus-specific immune response by inhibiting PD-L1. The drug has completed a Phase 1a/1b clinical trial evaluating safety, tolerability, pharmacokinetics, and pharmacodynamics of single- and multiple-ascending oral doses in healthy subjects and patients with chronic HBV infection.

Data from the trial showed AB-101 was generally well-tolerated, with evidence of high receptor occupancy in seven chronic HBV patients and hepatitis B surface antigen decline in two patients at the 30mg dose.

According to the World Health Organization, more than 250 million people worldwide have chronic HBV infection, with approximately 2 million cases in the United States. Approximately 1.1 million people die annually from complications related to the infection.