Initial data expected in the second half of 2023

WARMINSTER, PA, USA I March 16, 2023 I Arbutus Biopharma Corporation (Nasdaq: ABUS) (“Arbutus”), a clinical-stage biopharmaceutical company leveraging its extensive virology expertise to develop novel therapeutics that target specific viral diseases, today announced that the first subject has been dosed in the Phase 1 clinical trial evaluating the safety, tolerability, and pharmacokinetics of AB-161, Arbutus’ oral RNA destabilizer. AB-161 is being developed for use in an all-oral combination regimen to potentially provide a functional cure for patients with hepatitis B virus (HBV).

“We are pleased to move AB-161 into Phase 1 clinical development,” said William Collier, President and Chief Executive Officer of Arbutus Biopharma. “AB-161 was designed to reduce HBsAg levels and inhibit viral replication by selectively inhibiting essential host proteins that are important in stabilizing HBV RNAs from degradation. We remain committed to advancing our pipeline of assets to develop a functional cure for chronic HBV and look forward to sharing the initial data from the Phase 1 clinical trial of AB-161 in the second half of 2023.”

The Phase 1 double-blind, randomized, placebo-controlled, clinical trial is designed to investigate the safety, tolerability, and pharmacokinetics of oral administration of AB-161 in healthy subjects. The trial will enroll unique cohorts of ten healthy subjects each (8 active, 2 placebo) to receive single doses of AB-161. Safety assessments will be performed continuously and after day 7, if acceptable, the next cohort of subjects will be enrolled to receive an escalated dose of AB-161. A food effect assessment will also be conducted at a dose considered safe and well-tolerated and close to the anticipated therapeutic dose in chronic HBV patients.

Initial data from this Phase 1 single-ascending dose clinical trial in healthy subjects are expected in the second half of 2023.

About AB-161

AB-161 is our next generation oral small molecule RNA destabilizer, specifically designed to target the liver. Mechanistically, RNA destabilizers target the host proteins PAPD5/7, which are involved in regulating the stability of HBV RNA transcripts.  In doing so, RNA destabilizers lead to the selective degradation of HBV RNAs, thus reducing HBsAg levels and inhibiting viral replication. To provide a proprietary all-oral treatment regimen for patients with cHBV, we believe inclusion of a small molecule RNA destabilizer is key.

About HBV

Hepatitis B is a potentially life-threatening liver infection caused by the hepatitis B virus (HBV). HBV can cause chronic infection which leads to a higher risk of death from cirrhosis and liver cancer. Chronic HBV infection represents a significant unmet medical need. The World Health Organization estimates that over 290 million people worldwide suffer from chronic HBV infection, while other estimates indicate that approximately 2.4 million people in the United States suffer from chronic HBV infection. Approximately 820,000 people die every year from complications related to chronic HBV infection despite the availability of effective vaccines and current treatment options.

About Arbutus

Arbutus Biopharma Corporation (Nasdaq: ABUS) is a clinical-stage biopharmaceutical company leveraging its extensive virology expertise to develop novel therapeutics that target specific viral diseases. Our current focus areas include Hepatitis B virus (HBV), SARS-CoV-2, and other coronaviruses. To address HBV, we are developing a RNAi therapeutic, an oral PD-L1 inhibitor, and an oral RNA destabilizer to potentially identify a combination regimen with the aim of providing a functional cure for patients with chronic HBV by suppressing viral replication, reducing surface antigen and reawakening the immune system. We believe our lead compound, AB-729, is the only RNAi therapeutic with evidence of immune re-awakening. AB-729 is currently being evaluated in multiple phase 2 clinical trials. We also have an ongoing drug discovery and development program directed to identifying novel, orally active agents for treating coronaviruses, (including SARS-CoV-2), for which we have nominated a compound and have begun IND-enabling pre-clinical studies. In addition, we are also exploring oncology applications for our internal PD-L1 portfolio. For more information, visit

SOURCE: Arbutus Biopharma