Arbutus Biopharm Stock Price, News & Analysis

Arbutus Biopharma Corporation (Nasdaq: ABUS) is a clinical-stage biopharmaceutical company focused on infectious disease, with a primary emphasis on chronic hepatitis B virus (cHBV) infection. According to the company’s public disclosures, Arbutus is developing two main therapeutic candidates for cHBV and is also working to maximize the opportunity for its in-house developed Lipid Nanoparticle (LNP) delivery technology through its relationship with Genevant Sciences.

Core Focus: Chronic Hepatitis B (cHBV)

Arbutus describes cHBV as a significant unmet medical need. The company cites World Health Organization estimates that over 250 million people worldwide live with chronic HBV infection and that approximately 1.1 million people die each year from complications related to chronic infection, despite the availability of effective vaccines and existing treatment options. Other estimates referenced by Arbutus indicate that approximately 2 million people in the United States suffer from chronic HBV infection.

The company’s strategy centers on developing therapies that may enable a functional cure for cHBV. In its communications, Arbutus uses the term “functional cure” to describe patients who achieve hepatitis B surface antigen (HBsAg) loss and are able to discontinue all cHBV treatments, including nucleos(t)ide analogue (NA) therapy, while maintaining viral control.

Lead Candidate: Imdusiran (AB-729)

Imdusiran (AB-729) is described by Arbutus as an RNA interference (RNAi) therapeutic specifically designed to reduce all hepatitis B viral proteins and antigens, including HBsAg. The company states that lowering HBsAg is thought to be a key prerequisite to reawakening a patient’s immune system so it can control the virus. Imdusiran targets hepatocytes using Arbutus’ covalently conjugated N-Acetylgalactosamine (GalNAc) delivery technology, which enables subcutaneous administration.

Across Phase 1 and Phase 2a clinical trials, Arbutus has reported that imdusiran, in combination with NA therapy and either pegylated interferon alfa-2a (IFN) or low-dose nivolumab plus an immunotherapeutic, has led to a total of eight cHBV patients achieving what the company describes as functional cure. According to multiple company updates, these patients were able to discontinue all cHBV therapies, including NA therapy. Arbutus has also disclosed that, in its Phase 2a programs, additional patients met protocol-defined criteria to discontinue NA therapy and remained off treatment for extended follow-up periods.

Clinical data reported by Arbutus indicate that imdusiran has produced meaningful reductions in HBsAg and hepatitis B virus DNA. The company has also described imdusiran as generally safe and well-tolerated in the clinical studies conducted to date, including repeat dosing at different dose levels and follow-up periods extending beyond the dosing phase.

Second HBV Asset: AB-101 (Oral PD-L1 Inhibitor)

AB-101 is an oral PD-L1 inhibitor candidate that Arbutus is evaluating in a Phase 1a/1b clinical trial in healthy subjects and patients with cHBV. The company states that AB-101 is designed to allow for controlled immune checkpoint blockade while aiming to minimize systemic safety issues that are typically associated with checkpoint antibody therapies. Arbutus highlights the role of immune checkpoints such as PD-1/PD-L1 in immune tolerance and T-cell activation, including in the context of HBV.

In data presented from its ongoing Phase 1a/1b trial, Arbutus has reported that AB-101 was generally safe and well-tolerated in both single- and multiple-dose cohorts in healthy volunteers, with dose-dependent increases in PD-L1 receptor occupancy. The company has also reported that, in cHBV patients receiving 10 mg once daily for 28 days, AB-101 was well tolerated with PD-L1 receptor occupancy similar to that observed in healthy volunteers at the same dose. Across the cohorts reported, Arbutus has stated that there were no AB-101-related serious adverse events and no evidence of liver dysfunction.

Combination Approaches and Clinical Programs

Arbutus has conducted multiple Phase 2a clinical trials of imdusiran in combination regimens. In its IM-PROVE I trial, the company evaluated imdusiran with ongoing NA therapy and pegylated interferon alfa-2a. Data presented by Arbutus show that, in certain HBeAg-negative patients with baseline HBsAg levels below 1000 IU/mL, the combination of imdusiran, IFN and NA therapy led to functional cure in a subset of patients.

In the IM-PROVE II trial, Arbutus evaluated imdusiran with ongoing NA therapy followed by Barinthus Biotherapeutics’ T-cell stimulating immunotherapeutic VTP-300, with or without low-dose nivolumab. The company has reported that adding low-dose nivolumab to the regimen increased rates of HBsAg loss and that a proportion of patients in this cohort achieved functional cure as defined by the study.

Arbutus has also described analyses of immune biomarkers and HBV RNA dynamics in patients treated with imdusiran-based regimens, including observations of rapid HBV RNA decline during imdusiran lead-in and transient HBV RNA increases during IFN treatment associated with further HBsAg decline in some functional cure subjects.

Lipid Nanoparticle (LNP) Technology and Genevant

Beyond its HBV pipeline, Arbutus emphasizes its in-house developed LNP delivery technology. Through its ownership stake in and license agreement with Genevant Sciences, the company states that it is focused on maximizing the opportunity for this LNP platform. Arbutus and Genevant have filed patent infringement lawsuits against Moderna and against Pfizer/BioNTech related to the use of LNP technology in COVID-19 vaccines. The companies are seeking monetary relief and, in certain jurisdictions, injunctions, and have initiated enforcement actions across multiple countries.

Arbutus’ public statements describe its LNP technology as enabling delivery of nucleic acid-based medicines by encapsulating RNA within lipid nanoparticles. The company notes that this technology has been licensed to third parties and is the subject of ongoing litigation intended to protect its intellectual property.

Geographic and Regulatory Profile

Arbutus Biopharma Corporation is incorporated in British Columbia, Canada and lists its common shares on The Nasdaq Stock Market LLC under the trading symbol ABUS. In its SEC filings, the company identifies itself as a clinical-stage biopharmaceutical company focused on infectious disease. The filings also confirm that its common shares are registered under Section 12(b) of the Securities Exchange Act and that Arbutus files annual and quarterly reports, as well as current reports on Form 8-K, with the U.S. Securities and Exchange Commission.

Corporate Developments and Strategic Focus

In its recent disclosures, Arbutus has highlighted a corporate focus on advancing imdusiran and AB-101 while streamlining operations. The company has reported actions such as discontinuing discovery efforts, discontinuing the IM-PROVE III clinical trial, reducing its workforce, and exiting its corporate headquarters. Arbutus has also formed a Scientific Advisory Board composed of experts in cHBV treatment and late-stage clinical development to advise on its HBV pipeline strategy.

Arbutus has stated that it is reviewing development plans for a potential Phase 2b clinical trial of imdusiran in combination with IFN and NA therapy and evaluating next steps for AB-101 as part of a broader review of its cHBV programs. The company has also reported that it reacquired rights to imdusiran in Greater China and Taiwan following mutual termination of a prior license agreement with Qilu Pharmaceutical.

Position Within Pharmaceutical Preparation Manufacturing

Within the pharmaceutical preparation manufacturing industry, Arbutus is positioned as a clinical-stage developer of therapeutics for infectious disease, with a concentrated effort on chronic hepatitis B. Its activities span RNAi therapeutics, immune checkpoint modulation and nucleic acid delivery technologies. While the company’s programs remain in clinical development and subject to regulatory review, Arbutus’ disclosures emphasize its goal of contributing new therapeutic options for cHBV and of protecting and monetizing its LNP intellectual property through its collaboration with Genevant Sciences.