Vir Biotechnology to Showcase Full 96-Week Phase 2 SOLSTICE Hepatitis Delta Trial Results at European Association for the Study of the Liver Congress 2026
Vir Biotechnology announced that new clinical data from its Phase 2 SOLSTICE trial evaluating the investigational combination of tobevibart and elebsiran for chronic hepatitis delta (CHD) will be presented at the upcoming EASL Congress 2026 in Barcelona, Spain, from May 27–30, 2026. The presentations have been recognized by the European Association for the Study of the Liver (EASL), with the oral presentation selected for inclusion in the prestigious “Best of EASL 2026” program and the poster presentation selected for a dedicated poster tour session.
The company will present complete Week 96 endpoint results from the ongoing Phase 2 SOLSTICE clinical trial, which is evaluating the safety and efficacy of tobevibart (VIR-3434), both as a standalone therapy and in combination with elebsiran (VIR-2218), in participants living with chronic hepatitis delta virus (HDV) infection. The oral presentation is expected to provide important long-term data on viral suppression, safety outcomes, and the therapeutic potential of the investigational regimen for a disease area with significant unmet medical need.
The oral presentation, titled “Efficacy and safety of tobevibart (VIR-3434) alone or in combination with elebsiran (VIR-2218) in participants with chronic hepatitis delta virus infection: Week 96 endpoint results from the Phase 2 SOLSTICE trial,” will be featured during General Session II at the congress. The presentation will be delivered by Dr. Tarik Asselah on May 29, 2026, from 12:15 p.m. to 12:30 p.m. Central European Summer Time (CEST). The inclusion of the study in the “Best of EASL 2026” program highlights the scientific importance and clinical relevance of the data being presented.
In addition to the oral presentation, Vir Biotechnology will also showcase a Week 48 subgroup analysis from the SOLSTICE trial in a poster presentation focused on the impact of body mass index (BMI) on alanine aminotransferase (ALT) normalization after successful viral suppression in patients treated with the combination of tobevibart and elebsiran. ALT normalization is considered an important marker of liver health and inflammation reduction in chronic liver diseases.
The poster presentation, titled “SOLSTICE Week 48 subgroup analysis: Impact of BMI on ALT normalization after successful viral control in participants with chronic hepatitis delta virus infection treated with tobevibart plus elebsiran,” will be presented by Alina Jucov during the Poster Tour session focused on new and emerging therapies for viral hepatitis B and D. This session is scheduled for May 29, 2026, from 4:15 p.m. to 5:00 p.m. CEST.
The same poster will also be displayed during a broader poster session titled “Viral Hepatitis B and D: New therapies, unapproved therapies or strategies,” taking place on May 27, 2026, from 8:30 a.m. to 5:00 p.m. CEST. The poster tour selection further emphasizes the growing interest in innovative treatment approaches for chronic hepatitis delta, a disease for which therapeutic options remain extremely limited worldwide.
Chronic hepatitis delta is widely recognized as the most severe form of chronic viral hepatitis. The disease occurs in individuals infected with hepatitis B virus (HBV) who are also infected with hepatitis delta virus. HDV depends on the hepatitis B surface antigen (HBsAg) to replicate and spread within the liver. Patients with CHD often experience rapid progression to advanced liver disease, including cirrhosis, liver failure, hepatocellular carcinoma, and liver-related mortality.
The seriousness of the disease has gained increasing recognition within the medical and scientific community. Recently, the International Agency for Research on Cancer classified hepatitis delta virus infection as carcinogenic, underscoring the substantial long-term risks associated with persistent HDV infection. Research has shown that individuals with detectable HDV RNA face a significantly higher likelihood of developing severe liver complications compared with patients who achieve undetectable viral levels.
As a result, achieving HDV RNA target not detected (TND) status has emerged as a key virologic goal in the treatment of chronic hepatitis delta. Viral suppression and elimination are associated with improved liver outcomes and reduced risk of disease progression. Despite this urgent need, there are currently no approved therapies for CHD in the United States, while treatment options in Europe and other regions remain limited.
Vir Biotechnology’s investigational combination approach aims to address this challenge by targeting multiple stages of the HDV life cycle simultaneously. Tobevibart and elebsiran are administered monthly as two sequential subcutaneous injections and are designed to work together to reduce viral replication and limit disease progression.
Tobevibart is a broadly neutralizing monoclonal antibody directed against hepatitis B surface antigen. By targeting HBsAg, the therapy is designed to block viral entry into liver cells and reduce the amount of circulating viral and subviral particles in the bloodstream. The investigational antibody was discovered using Vir Biotechnology’s proprietary monoclonal antibody discovery platform and has been engineered to enhance immune engagement and improve clearance of immune complexes.
The Fc domain of tobevibart incorporates Xencor’s Xtend™ technology, which is intended to extend the therapy’s half-life and potentially improve dosing convenience and durability of response.
Elebsiran, meanwhile, is an investigational small interfering RNA (siRNA) therapy targeting hepatitis B virus RNA transcripts. Licensed from Alnylam Pharmaceuticals, elebsiran is designed to suppress production of hepatitis B surface antigen by degrading HBV RNA within infected cells. Because HDV relies on HBsAg for replication, reducing its presence may significantly impair the virus’s ability to persist and spread.
Together, the combination strategy seeks to interfere with both viral entry and the ongoing production of the viral components necessary for HDV survival. Researchers believe that this multi-targeted mechanism may offer a promising new therapeutic pathway for patients with chronic hepatitis delta who currently have limited treatment choices.
Vir Biotechnology is a clinical-stage biopharmaceutical company focused on developing innovative therapies designed to harness and enhance the immune system to combat serious infectious diseases and cancer. In addition to its hepatitis delta program, the company is advancing a pipeline of oncology candidates, including multiple PRO-XTEN® dual-masked T-cell engager therapies being studied across solid tumor indications.
The company also maintains a broader preclinical research portfolio spanning infectious diseases and oncology. Vir Biotechnology holds exclusive rights to the universal PRO-XTEN® masking platform for oncology and infectious disease applications. PRO-XTEN® is a trademark of Amunix Pharmaceuticals, a subsidiary of Sanofi.
The presentations at EASL Congress 2026 are expected to further strengthen Vir Biotechnology’s position in the field of hepatitis delta research and provide additional insight into the long-term clinical potential of the tobevibart and elebsiran combination regimen. With chronic hepatitis delta remaining one of the most challenging and underserved viral liver diseases globally, the upcoming data presentations could represent an important step toward advancing new treatment strategies for patients in need.
About Chronic Hepatitis Delta (CHD)
CHD is the most severe form of chronic viral hepatitis1 and was recently classified as carcinogenic by the International Agency for Research on Cancer.2 People living with the disease rapidly progress to cirrhosis, liver failure3 and liver-related death.1 Because ongoing hepatitis delta virus (HDV) replication drives disease progression, achieving undetectable virus, as defined by HDV RNA TND (target not detected), is considered an important virologic marker associated with improved clinical outcomes in CHD.4 Individuals with CHD who have detectable HDV RNA are at a higher risk of experiencing any liver-related event, including developing compensated and decompensated cirrhosis, hepatocellular carcinoma, liver transplantation and mortality, compared to patients with undetectable HDV RNA.4 There are currently no approved treatments in the U.S., and options are limited in the European Union and globally.
Tobevibart and elebsiran are investigational agents being evaluated as a novel combination regimen administered monthly as two separate sequential subcutaneous injections for the treatment of CHD. The combination is designed to disrupt the HDV life cycle at multiple points by addressing both viral entry and the sustained presence of hepatitis B surface antigen (HBsAg) that enables ongoing HDV replication.
Tobevibart is an investigational broadly neutralizing monoclonal antibody (mAb) targeting HBsAg. It is designed to inhibit the entry of hepatitis B and hepatitis delta viruses into hepatocytes and to reduce the level of circulating viral and subviral particles in the blood. Tobevibart was identified using Vir Biotechnology’s proprietary mAb discovery platform. The Fc domain has been engineered to increase immune engagement and clearance of HBsAg immune complexes and incorporates Xencor’s Xtend™ technology to extend half-life.
Elebsiran is an investigational hepatitis B virus-targeting small interfering ribonucleic acid (siRNA) licensed from Alnylam Pharmaceuticals, Inc. It is designed to degrade hepatitis B virus RNA transcripts and limit the production of HBsAg.
