Unsplash License / Archive laboratory illustration, cropped / Not the Vir trial
Vir Biotechnology said its experimental monthly treatment for chronic hepatitis delta met the main goal of a late-stage clinical trial, moving the two-drug regimen closer to a planned U.S. regulatory submission in mid-2027.
The company’s November 8 release reported that 44% of treated participants had both undetectable hepatitis delta virus and normalized ALT blood-test levels after 48 weeks. That compared with 0% in a delayed-treatment group assessed at Week 12. The different assessment times are important: this was not a comparison of two groups each observed without treatment for 48 weeks.
The Phase 3 ECLIPSE 1 trial enrolled 124 adults, randomly assigning 83 to receive elebsiran and tobevibart and 41 to delayed treatment. The delayed group began therapy at Week 12. The combination is given monthly as two separate injections under the skin.
Vir said the primary result was statistically significant, with a p-value below 0.0001. A key secondary goal was also met: 79% of treated participants had undetectable viral RNA at Week 48, compared with 0% in the delayed-treatment group at Week 12. Undetectable means the test did not detect the viral target; it does not establish a cure.
The potential beneficiaries are adults with chronic hepatitis delta, a serious liver infection for which treatment options remain limited. Vir said the trial included patients with advanced disease and that undetectable virus was seen in participants both with and without cirrhosis. The findings offer evidence of viral suppression, rather than proof that the regimen prevents liver failure, cancer or death over the longer term.
All patients completed 48 weeks of treatment, according to the company. It reported no treatment interruptions or discontinuations and one Grade 3 treatment-related decrease in neutrophil count, which resolved in 15 days. Most treatment-related adverse events were mild to moderate and temporary; flu-like symptoms were the most common.
Elebsiran and tobevibart remain investigational, and the combination is not an approved treatment. These are company-reported topline results, not a regulatory decision. The longer-term benefits and risks, and the outcome of any application, remain to be determined.
Vir expects results from the ECLIPSE 2 and ECLIPSE 3 trials in the first quarter of 2027 and plans to use data from all three studies in its regulatory filing package. It will discuss the new findings on a conference call Monday, November 9, at 8:30 a.m. Eastern, with a webcast available through its investor website.
Separate Phase 2 data track longer treatment and early follow-up after stopping
In a separate November 8 company announcement, Vir reported expanded results from the Phase 2 SOLSTICE study: all 28 participants who completed 96 weeks of combination therapy had undetectable hepatitis delta virus. That is a result for a treatment-completer subset, not the entire study population, and is separate from the Phase 3 ECLIPSE 1 results above.
Vir also reported an exploratory analysis of 10 participants who chose to stop treatment after maintaining undetectable virus for at least 96 weeks. All 10 had a sustained viral response 12 weeks after their last dose. Among those who had reached later follow-up points, seven had sustained responses at 24 weeks and one at 48 weeks. Those figures do not mean all 10 had been followed for 48 weeks.
The company said all 10 continued follow-up and had stable ALT levels, with no viral rebound or ALT flares observed at the interim assessment. But it called the analysis preliminary and exploratory, with incomplete follow-up and safety data not yet fully assessed. The small, selected group may not represent the broader study population; the findings do not establish a sustained treatment-free response or cure.
JBizNews Desk | San Francisco
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