Imdusiran data from IM-PROVE I and IM-PROVE II Phase 2a clinical trials to be presented at upcoming AASLD - The Liver Meeting 2024

Multiple-ascending doses of AB-101 in healthy subjects in the Phase 1a/1b clinical trial were generally safe and well-tolerated with evidence of receptor occupancy

Now dosing cHBV patients with AB-101 in Part 3 of the Phase 1a/1b clinical trial

Cash runway into the fourth quarter of 2026

Conference Call and Webcast Today at 8:45 AM ET

WARMINSTER, Pa., Nov. 06, 2024 (GLOBE NEWSWIRE) -- Arbutus Biopharma Corporation (Nasdaq: ABUS) ("Arbutus” or the "Company”), a clinical-stage biopharmaceutical company leveraging its extensive virology expertise to develop a functional cure for people with chronic hepatitis B virus (cHBV) infection, today reports third quarter 2024 financial results and provides a corporate update.

"We are making significant progress in advancing the development of imdusiran to bring hope to millions of cHBV patients globally,” said Michael J. McElhaugh, Interim President and Chief Executive Officer of Arbutus Biopharma. "In June, we shared promising data from our IM-PROVE I Phase 2a clinical trial, showing that some patients treated with imdusiran and interferon were trending towards a functional cure. We look forward to presenting follow-up data from this trial, as well as end-of-treatment data from patients that received nivolumab in addition to imdusiran and VTP-300 in our IM-PROVE II Phase 2a trial, at the upcoming AASLD meeting. Assuming continued positive data, and with a projected cash runway extending into the fourth quarter of 2026, we are well-positioned to advance imdusiran into a Phase 2b clinical trial as a cornerstone in a treatment regimen aimed at functionally curing cHBV.”

Mr. McElhaugh continued, "Our proprietary oral PD-L1 checkpoint inhibitor, AB-101, is progressing well, as we continue to see dose-dependent receptor occupancy and have now advanced into dosing cHBV patients in our Phase 1a/1b clinical trial. We look forward to providing updates as this trial progresses.”

Clinical Development Update

Imdusiran (AB-729, RNAi Therapeutic) 

• End-of-treatment data from the IM-PROVE I Phase 2a clinical trial evaluating the safety, tolerability and antiviral activity of the combination of imdusiran (4 or 6 doses over 24 or 48 weeks, respectively), nucleos(t)ide analogue (NA) therapy and a short course of pegylated interferon alfa-2a (IFN, 12 or 24 weeks) in patients with cHBV was presented at the EASL Congress in June. The data showed that 33.3% (n=4/12) of patients in Cohort A1 receiving 48 weeks (6 doses) of imdusiran combined with 24 weeks of IFN and NA therapy achieved HBsAg loss at the end-of-treatment that was maintained in 100% of these patients 24 weeks after completing imdusiran and IFN treatment. HBsAg loss was achieved and maintained in 67% of those patients with HBsAg less than 1000 IU/mL at baseline.  A total of six patients from Cohort A1 (n=4) and Cohort A2 (n=2) seroconverted with HBsAg loss. At the time the data was reported, all six of those patients had stopped all therapy, with two of those patients reaching 12 weeks off all therapy with sustained HBsAg and HBV DNA loss. The combination of imdusiran and IFN in this clinical trial was generally safe and well-tolerated. The Company will present a late-breaker poster with additional follow-up data at the upcoming AASLD-The Liver Meeting 2024 later this month.

• End-of treatment data from the IM-PROVE II Phase 2a clinical trial evaluating the safety and immunogenicity of imdusiran, NA therapy and Barinthus Bio's VTP-300, an HBV antigen-specific immunotherapy was presented at the EASL Congress in June. The data showed that the combination of imdusiran and VTP-300 was generally safe and well-tolerated. At 24-weeks post-end of treatment, statistical significance (p<0.05) was achieved in HBsAg levels between the VTP-300 arm (n=5) and placebo (n=6). IM-PROVE II includes an additional cohort of patients who received 4 doses of imdusiran plus NA therapy for 24 weeks followed by VTP-300 plus up to two low doses of nivolumab, an approved anti-PD-1 monoclonal antibody. The Company will present a late-breaker poster with preliminary end-of-treatment data from this additional cohort at the upcoming AASLD - The Liver Meeting 2024 in November.

• AB-101-001 is a Phase 1a/1b double-blind, randomized, placebo-controlled clinical trial designed to investigate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of single- and multiple-ascending oral doses of AB-101 in healthy subjects and patients with cHBV.
• Part 2 of this clinical trial has enrolled to date two sequential cohorts of ten healthy subjects each receiving 10 mg or 25 mg of AB-101 (n=8) or placebo (n=2) daily for 7 days. AB-101 was generally well-tolerated with evidence of dose-dependent receptor occupancy. In the 25 mg cohort, all subjects showed evidence of receptor occupancy, with seven of the eight subjects demonstrating receptor occupancy greater than 70% during the 7-day dosing period.
• Arbutus has moved into Part 3 of this clinical trial which evaluates repeat dosing of AB-101 for 28 days in patients with cHBV and expects to report preliminary data in the first half of next year.

• Expert reports and expert depositions continue in the Moderna lawsuit. A trial date has been set for September 24, 2025, and is subject to the Court's availability.
• The lawsuit against Pfizer/BioNTech is ongoing and a date for the claim construction hearing has been set for December 18, 2024.  

Financial Results

Cash, Cash Equivalents and Investments

As of September 30, 2024, the Company had cash, cash equivalents and investments in marketable securities of $130.8 million compared to $132.3 million as of December 31, 2023. During the nine months ended September 30, 2024, the Company used $54.5 million in operating activities, which was partially offset by $44.1 million of net proceeds from the issuance of common shares under its "at-the-market” offering program (ATM Program) and $6.1 million of proceeds from the exercise of stock options. The Company did not issue any common shares under its ATM program in the third quarter of 2024. The Company expects its 2024 cash burn to range from $63 million to $67 million.  With the organizational changes in the third quarter, the Company believes its cash, cash equivalents and investments in marketable securities will be sufficient to fund its operations into the fourth quarter of 2026.

Revenue

Total revenue was $1.3 million for the three months ended September 30, 2024 compared to $4.7 million for the same period in 2023. The decrease of $3.4 million was due primarily to: i) a decrease in license revenue recognized under the Company's licensing agreement with Qilu Pharmaceutical; and ii) a decrease in license royalty revenue from Alnylam due to lower sales of ONPATTRO in 2024 compared to 2023.

Operating Expenses

Research and development expenses were $14.3 million for the three months ended September 30, 2024 compared to $20.2 million for the same period in 2023. The decrease of $5.9 million was due primarily to the discontinuation of the Company's coronavirus and AB-161 programs in September 2023, along with related headcount reductions. General and administrative expenses were $4.5 million for the three months ended September 30, 2024 compared to $5.8 million for the same period in 2023. The decrease of $1.3 million was due primarily to decreased employee compensation and non-cash stock-based compensation expenses due to headcount reductions. The Company also incurred a $3.6 million one-time restructuring charge in the third quarter of 2024 related to its decision to cease all discovery efforts, discontinue its IM-PROVE III clinical trial, and reduce headcount to streamline the organization with a focus on advancing the clinical development of imdusiran and AB-101.

Net Loss

The Company's net loss was $19.7 million for the three months ended September 30, 2024 and $20.1 million for the same period in 2023, with a loss per basic and diluted common share of $0.10 and $0.12, respectively.

Outstanding Shares

As of September 30, 2024, the Company had approximately 189.4 million common shares issued and outstanding. In addition, the Company had approximately 18.7 million stock options and unvested restricted stock units outstanding as of September 30, 2024. Roivant Sciences Ltd. owned approximately 21% of the Company's outstanding common shares as of September 30, 2024.