Arbutus Biopharma Corporation

Overview

Arbutus Biopharma is a clinical-stage biopharmaceutical company focused on infectious disease, with primary emphasis on chronic hepatitis B (cHBV). Its lead therapeutic approaches target viral antigen reduction and immune activation for potential HBV functional cure.

Lead programs

• Imdusiran (AB-729)

  • GalNAc-conjugated, subcutaneously delivered RNA interference therapeutic that targets HBV antigens (including HBsAg) to suppress HBV DNA, HBV RNA, and viral proteins.
  • Clinical evidence from multiple Phase 2a studies (IM-PROVE I and II and other trials) has shown reductions in HBsAg, HBV DNA, and HBV RNA. A subset of patients achieved functional cure or remained off nucleos(t)ide analog (NA) therapy for extended periods after treatment, including cohorts treated in combination with interferon or immune checkpoint modulation.

• AB-101

  • Oral PD-L1 inhibitor designed to activate HBV-specific immune responses.
  • Phase 1a/1b program evaluated safety, tolerability, PK/PD and receptor occupancy in healthy subjects and cHBV patients. Clinical data demonstrated PD-L1 receptor occupancy and tolerability at certain doses; a poster at AASLD 2025 highlighted occupancy at a 30 mg daily dose.
  • The IND for AB-101 has been under FDA review since a regulatory hold in 2023; the company is addressing regulatory requirements and pursuing appropriate trial sites outside the U.S. where applicable.

Clinical development highlights

• IM-PROVE I (Phase 2a): Proof-of-concept study of imdusiran with short-course interferon and ongoing NA therapy in NA-suppressed, non-cirrhotic cHBV patients. Reported data in 2024–2025 showed functional cure in a subset when combined with interferon, with benefit observed across genotypes A–D.
• IM-PROVE II (Phase 2a): Evaluated imdusiran in combination with Barinthus’ VTP-300 immunotherapeutic and included a cohort with low-dose nivolumab. Data in 2024–2025 showed higher HBsAg seroclearance rates with low-dose nivolumab; by 2025, 53% of patients across IM-PROVE II cohorts achieved functional cure or remained off NA therapy for at least 48 weeks after stopping NA therapy.
• Combination strategies with immune modulators and checkpoint inhibitors remain a focus for advancing HBV curative approaches.

Collaborations, royalties, and IP

• LNP and RNA delivery IP form a central part of Arbutus’s intellectual property portfolio. The company holds litigation and licensing positions related to lipid nanoparticle (LNP) technology, including matters involving Moderna and Pfizer/BioNTech, and maintains collaborations with Genevant.
• Genevant / Roivant
  • Arbutus held approximately 16% of Genevant common equity as of 12/31/2025.
  • Under the Genevant License, Arbutus is entitled to a share of certain Genevant sublicensing revenue or a portion of net sales in collaboration arrangements.
  • The Moderna LNP litigation settlement (March 2026) includes a $950 million noncontingent payment and up to $1.3 billion in contingent payments tied to §1498 appeal outcomes; Arbutus and Genevant are each entitled to 20% of the noncontingent payment (after litigation costs).
• Alnylam / ONPATTRO royalties
  • Arbutus had royalty entitlements historically tied to ONPATTRO. Some royalty streams were sold to OMERS in 2019; OMERS has received royalties totaling about $26.5 million through 12/31/2025 and will continue to receive royalties until a $30 million milestone is reached, after which 100% reverts to Arbutus.
  • Arbutus retained a separate royalty entitlement on ONPATTRO (0.75%–1.125% on global net sales) from Acuitas. In December 2025, Arbutus recognized $0.5 million in revenue from a milestone related to Alnylam’s use of LNP technology; that payment was received in January 2026.
• Other agreements
  • Qilu Pharmaceutical license for Greater China and Taiwan was terminated in June 2025; previously deferred revenue related to that agreement was recognized in Q2 2025.
  • Ongoing royalty and milestone streams arise from historical collaborations and licenses.

Financials and liquidity (as of 12/31/2025)

• Cash, cash equivalents, and investments: approximately $91.5 million.
• Accumulated net deficit since inception: approximately $1.4 billion.
• Revenue: No product sales to date. 2025 revenue included $0.5 million recognized from a milestone related to Alnylam/LNP (cash received January 2026).
• Moderna settlement proceeds:
  • $950.0 million noncontingent payment due on or before July 8, 2026.
  • Up to $1.3 billion contingent payment payable upon favorable §1498 appeal outcomes.
  • Arbutus’s share of the noncontingent payment is 20% under the Genevant License (after litigation costs).
• The company has incurred operating losses historically and is evaluating capital allocation, including a potential return of capital to shareholders in Q3 2026 following receipt of its share of the noncontingent settlement payment.

Operations and structure

• Headquarters and workforce
  • Corporate headquarters in Warminster, PA, was exited in 2025; the company has adopted a remote work model.
  • Employee count: 19 full-time employees as of 12/31/2025.
• Manufacturing and development
  • Clinical manufacturing and development are outsourced to third-party contract manufacturers; Arbutus does not operate large-scale internal manufacturing facilities and has adopted a lean operating model with substantial outsourcing.
• Strategic focus
  • Prioritized cHBV programs (imidusiran/AB-729 and AB-101) and the LNP platform, with active cost management, workforce adjustments, and strategic board-level changes during 2025.
• Regulatory and IP activities
  • Ongoing patent strategies and litigation related to LNP technology and HBV programs. The AB-101 IND has been subject to an FDA hold since 2023 and the company is engaging with regulatory authorities while pursuing appropriate clinical sites internationally.

Key numbers at a glance (as of 12/31/2025)

• Employees: 19 full-time
• Cash, equivalents, and investments: $91.5 million
• Accumulated net deficit: ~ $1.4 billion
• 2025 revenue: $0 from product sales; $0.5 million recognized in 2025 from an Alnylam/LNP milestone (cash received in 2026)
• Moderna settlement: $950 million noncontingent payment by 7/8/2026; contingent up to $1.3 billion
• Genevant ownership: ~16% of Genevant common equity
• Royalties: ONPATTRO-related royalties historically due to Arbutus; OMERS received $26.5 million through 12/31/2025
• Headquarters: exited Warminster, PA; remote work model

Scope

This summary reflects Arbutus’s clinical programs, collaboration and IP positions, financial situation, and corporate structure as described through December 31, 2025, with subsequent settlement developments noted where relevant.