Benzinga | Jul 7, 2021 07:02AM EDT

Arbutus Receives Authorization to Proceed with an Investigational New Drug Application for AB-729, It's Proprietary Subcutaneously-Delivered RNAi Agent

Arbutus Biopharma Corporation (NASDAQ:ABUS), a clinical-stage biopharmaceutical company primarily focused on developing a cure for people with chronic hepatitis B virus (HBV) infection (CHB), as well as therapies to treat coronaviruses (including COVID-19), today announced it has received authorization from the U.S. Food and Drug Administration to proceed with its Investigational New Drug (IND) application for AB-729 in a Phase 2a clinical trial. The Phase 2a proof-of-concept clinical trial will evaluate the safety and efficacy of AB-729 in combination with ongoing nucleos(t)ide analog (NA) therapy and short courses of Peg-IFN?-2a in subjects with CHB.

William Collier, President and Chief Executive Officer of Arbutus, stated, "The acceptance of our IND application is an important step forward for AB-729 and supports our objective to establish its value as a cornerstone therapy for patients with CHB. We look forward to the initiation of this proof-of-concept Phase 2a clinical trial in this quarter."

Gaston Picchio, PhD, Chief Development Officer at Arbutus, stated, "We are gratified that our IND submission for AB-729, in combination with Peg-IFN, in subjects with chronic hepatitis B viral infection has been deemed safe to proceed. This Phase 2a trial will allow us to investigate if short courses of Peg-IFN, following a pronounced HBsAg suppression and potential immune reactivation by AB-729, could contribute to achieving a functional cure in HBeAg negative chronic hepatitis B subjects."

About the Phase 2a Clinical Trial

This is a randomized, open label, multicenter Phase 2a trial investigating the safety and antiviral activity of AB-729 in combination with ongoing NA therapy and short courses of Peg-IFN?-2a in subjects with CHB. Pending protocol finalization, the trial is expected to enroll 40 stably NA-suppressed, HBeAg negative, non-cirrhotic CHB subjects. After a 24-week dosing period of AB-729 (60 mg SC every 8 weeks (Q8W)), subjects will be randomized into one of 4 groups:

* A1: AB-729 + NA + weekly Peg-IFN?-2a for 24 weeks (N = 12)

* A2: NA + weekly Peg-IFN?-2a for 24 weeks (N = 12)

* B1: AB-729 + NA + weekly Peg-IFN?-2a for 12 weeks (N = 8)

* B2: NA + weekly Peg-IFN?-2a for 12 weeks (N = 8)

After completion of the assigned Peg-IFN?-2a treatment period, all subjects will remain on NA therapy for the initial 24-week follow up period, and then will discontinue NA treatment if treatment stopping criteria are met. If subjects stop NA therapy, they will enter an intensive follow-up period for 48 weeks.

About AB-729

AB-729 is an RNA interference (RNAi) therapeutic targeted to hepatocytes using Arbutus' novel covalently conjugated N-acetylgalactosamine (GalNAc) delivery technology that enables subcutaneous delivery. AB-729 inhibits viral replication and reduces all HBV antigens tested, including hepatitis B surface antigen, in preclinical models. Reducing hepatitis B surface antigen is thought to be a key prerequisite to enable reawakening of a patient's immune system so as allow it to respond to the virus. Based upon clinical data generated thus far in an ongoing single- and multi-dose Phase 1a/1b clinical trial, AB-729 has demonstrated positive safety and tolerability data and meaningful reductions in hepatitis B surface antigen.