Arbutus Biopharma Doses First Subject in Phase 1 Clinical Trial with its Oral RNA Destabilizer, AB-161

Arbutus Biopharma (NASDAQ: ABUS ) 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.