A Study to Evaluate Tobevibart+Elebsiran Versus Bulevirtide in Chronic HDV Infection

January 15, 2026 updated by: Vir Biotechnology, Inc.

A Phase 2b Randomized, Open-Label Study to Evaluate the Efficacy and Safety of Tobevibart+Elebsiran Combination Therapy Versus Bulevirtide in Participants With Chronic HDV Infection (ECLIPSE 3)

A Study to Evaluate Tobevibart+Elebsiran versus Bulevirtide in Chronic HDV Infection

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

100

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Belgium
      • Brussels, Belgium, 1020
        • Investigative Site
      • Brussels, Belgium, 1070
        • Investigative Site
      • Edegem, Belgium, 2650
        • Investigative Site
  • Bulgaria
      • Sofia, Bulgaria, 1431
        • Investigative Site
      • Sofia, Bulgaria, 1407
        • Investigative Site
      • Stara Zagora, Bulgaria, 6003
        • Investigative Site
  • France
      • Clichy, France, 92110
        • Investigative Site
      • Créteil, France, 94000
        • Investigative Site
      • Limoges, France, 87042
        • Investigative Site
      • Rennes, France, 35000
        • Investigative Site
      • Toulouse, France, 31059
        • Investigative Site
  • Germany
      • Hanover, Germany, 30625
        • Investigative Site
  • Moldova
      • Chisinau, Moldova, 2025
        • Investigative Site
  • Netherlands
      • Amsterdam, Netherlands, 1081 HV
        • Investigative Site
      • Nijmegen, Netherlands, 6525 GA
        • Investigative Site
      • Rotterdam, Netherlands, 3015 GD
        • Investigative Site
  • Pakistan
      • Karachi, Pakistan, 74800
        • Investigative Site
      • Karachi, Pakistan, 75600
        • Investigative Site
      • Lahore, Pakistan, 54800
        • Investigative Site
      • Rawalpindi, Pakistan, 46000
        • Investigative Site
  • Romania
      • Bucharest, Romania, 021105
        • Investigative Site
      • Bucharest, Romania, 022328
        • Investigative Site
      • Bucharest, Romania, 030303
        • Investigative Site
  • Spain
      • Barcelona, Spain, 08028
        • Investigative Site
      • Madrid, Spain, 28064
        • Investigative Site
      • Valencia, Spain, 46014
        • Investigative
  • Ukraine
      • Kyiv, Ukraine, 01135
        • Investigative Site
  • United Kingdom
      • London, United Kingdom, SE5 9RS
        • Investigative Site
      • London, United Kingdom, E1 1BB
        • Investigative Site
      • Manchester, United Kingdom, M8 5RB
        • Investigative Site
      • Nottingham, United Kingdom, NG7 2UH
        • Investigative Site

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Male or female ages 18 to 70 years at screening
  2. Positive HDV antibody or positive HDV RNA PCR result for at least 6 months prior to screening and HDV RNA ≥ 500 IU/mL at screening
  3. Noncirrhotic or compensated cirrhotic liver disease at screening
  4. On NRTI therapy against HBV for at least 12 weeks prior to day 1 or have HBV DNA < 10 IU/ml at screening, currently on locally approved NRTI therapy

Exclusion Criteria:

  1. Serum ALT ≥ 5 × ULN
  2. Any clinically significant chronic or acute medical or psychiatric condition that makes the participant unsuitable for participation.
  3. History of significant liver disease from non-HBV or non-HDV etiology
  4. History of allergic reactions, hypersensitivity, or intolerance to study drug, its metabolites, or excipients.
  5. History of anaphylaxis
  6. History of immune complex disease
  7. History of autoimmune disorder
  8. Current therapy or therapy within 24 weeks of screening with an immunomodulatory agent, immune checkpoint inhibitors, immunosuppressants, cytotoxic or chemotherapeutic agent, or chronic systemic corticosteroids.
  9. Any previous treatment with Bulivertide

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Arm 1
Participants will receive treatment with tobevibart + elebsiran up to 240 weeks.
Drug: Tobevibart
Tobevibart administered by subcutaneous injection
Other Names:
  • VIR-3434
Drug: Elebsiran
Elebsiran administered by subcutaneous injection
Other Names:
  • VIR-2218
Experimental: Arm 2
Participants will receive Bulevirtide for approximately 48 weeks and switch to receive tobevibart + elebsiran for additional 192 weeks
Drug: Tobevibart
Tobevibart administered by subcutaneous injection
Other Names:
  • VIR-3434
Drug: Elebsiran
Elebsiran administered by subcutaneous injection
Other Names:
  • VIR-2218
Drug: Bulevirtide
Bulevirtide administered by subcutaneous injection
Other Names:
  • Hepcludex

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
HDV RNA < Lower Limit of Quantification (LLOQ), Target not detected (TND) at Week 48
Time Frame: Week 48
Week 48
HDV RNA < Lower Limit of Quantification (LLOQ), Target not detected (TND) 24 weeks after end of treatment
Time Frame: 24 Weeks after End of Treatment
24 Weeks after End of Treatment
Incidence of treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs) through Week 48
Time Frame: Week 48
Week 48

Secondary Outcome Measures

Outcome Measure
Time Frame
Change from baseline in HDV RNA at Week 48
Time Frame: Week 48
Week 48
Change from baseline in ALT at Week 48
Time Frame: Week 48
Week 48
HDV RNA < Lower Limit of Quantification (LLOQ), Target not detected (TND) at Week 96, Week 120, Week 144, Week 192 and Week 240
Time Frame: Week 96, Week 120, Week 144, Week 192 and Week 240
Week 96, Week 120, Week 144, Week 192 and Week 240
Change from baseline in HDV RNA at Week 96, Week 120, Week 144, Week 192 and Week 240
Time Frame: Week 96, Week 120, Week 144, Week 192 and Week 240
Week 96, Week 120, Week 144, Week 192 and Week 240
Change from baseline in ALT at Week 96, Week 120, Week 144, Week 192 and Week 240
Time Frame: Week 96 to Week 120, Week 144, Week 192 and Week 240
Week 96 to Week 120, Week 144, Week 192 and Week 240

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Vir Biotechnology, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 5, 2025

Primary Completion (Estimated)

November 1, 2026

Study Completion (Estimated)

July 1, 2030

Study Registration Dates

First Submitted

August 19, 2025

First Submitted That Met QC Criteria

August 19, 2025

First Posted (Estimated)

August 27, 2025

Study Record Updates

Last Update Posted (Estimated)

January 16, 2026

Last Update Submitted That Met QC Criteria

January 15, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • VIR-CHDV-V206

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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