A Phase 3 interventional study of Tobevibart and Elebsiran in Viral Hepatitis, sponsored by Vir Biotechnology, Inc.. Active, not recruiting at 38 sites in 7 countries. Open to participants aged 18 Years to 70 Years. Per ClinicalTrials.gov, last updated 2026-07-13.
Sponsored by Vir Biotechnology, Inc. · Phase 3, Interventional, and Treatment
This is a multicenter, open label, randomized Phase 3 clinical study to evaluate tobevibart + elebsiran in participants with Chronic HDV Infection not virologically suppressed with bulevirtide
343 studies on the registry are indexed under Hepatitis; 51 are open to participants now.
This study's planned enrollment of 150 is above the median of 85 across 245 interventional studies indexed under Hepatitis.
Browse Hepatitis studies →Vir Biotechnology, Inc. is the lead sponsor of 22 studies on the registry; 2 are open to participants now.
Of its 15 completed or terminated interventional studies of FDA-regulated products, 11 (73%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
PD-1, PD-L1 and CTLA-4 are proteins that act as brakes on the immune system. Checkpoint inhibitors, such as pembrolizumab or nivolumab, block them so the immune system can attack a cancer.
PD-L1 can also be measured in a tumour sample. Some scores count stained tumour cells only (TPS); others also count certain immune cells (CPS). The study names the score and the minimum it uses.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
PD-1, PD-L1 and checkpoint inhibitors
PD-1, PD-L1 and CTLA-4 are proteins that act as brakes on the immune system. Checkpoint inhibitors, such as pembrolizumab or nivolumab, block them so the immune system can attack a cancer.
PD-L1 can also be measured in a tumour sample. Some scores count stained tumour cells only (TPS); others also count certain immune cells (CPS). The study names the score and the minimum it uses.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive treatment with tobevibart + elebsiran up to 240 weeks.
Drug: Tobevibart · Drug: Elebsiran
Participants will receive Bulevirtide for 24 weeks and switch to receive tobevibart + elebsiran for additional 216 weeks
Drug: Tobevibart · Drug: Elebsiran · Drug: Bulevirtide
Tobevibart administered by subcutaneous injection
Also known as: VIR-3434
Elebsiran administered by subcutaneous injection
Also known as: VIR-2218
Bulevirtide administered by subcutaneous injection
Also known as: Hepcludex
HDV RNA < Lower Limit of Quantification (LLOQ), Target not detected (TND) at Week 24
Time frame: Week 24
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
Incidence of Treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs) through Week 24, Week 48, Week 96, Week 120, Week 144, Week 192, and Week 240
Time frame: Week 24, Week 48, Week 96, Week 120, Week 144, Week 192, and Week 240
HDV RNA < Lower Limit of Quantification (LLOQ), Target not detected (TND) at Week 48, Week 96, Week 120, Week 144, Week 192 and Week 240
Time frame: Week 48 , Week 96, Week 120, Week 144, Week 192 and Week 240
Change from baseline in ALT at Week 24, Week 48, Week 96, Week 120, Week 144, Week 192, and Week 240
Time frame: Week 24, Week 48, Week 96, Week 120, Week 144, Week 192, and Week 240
Started Jul 2025 (actual). Primary completion is estimated for Dec 2026, 17 months after the start.
Of 23 phase 3 interventional studies under Hepatitis, half reached primary completion within 26 months of starting (the median), counting those still running; a quarter within 20 and three quarters within 38. This study's planned 17 months is below that.
How these figures are worked out, and which studies are left out of them.
This study is active, not recruiting, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drugs tested here: Tobevibart · Elebsiran