Vir Biotechnology meets Phase 3 hepatitis delta endpoint with 44% response

A Phase 3 hepatitis delta trial met its primary endpoint with a 44 per cent response rate, as Vir Biotechnology, Inc. NASDAQVIR reported results on Sunday. One patient had a Grade 3 treatment-related adverse event, with no treatment interruptions or discontinuations.

The comparison used treated patients at Week 48 and delayed-treatment patients at Week 12, when that group began therapy. Response required undetectable hepatitis delta virus plus normalization of the liver enzyme alanine aminotransferase, or ALT; the delayed-treatment response rate was zero, with p below 0.0001.

Vir is a San Francisco clinical-stage biotechnology company developing treatments for serious infectious diseases and cancer.

The company plans an FDA submission in mid-2027, following further pivotal results expected in the first quarter. Its Nov. 4 financial update reported approximately US$901.3 million in cash, cash equivalents and investments at Sept. 30. Based on its current operating plans, Vir expects those resources to fund operations into the second half of 2028.

Read more: Moderna reports US$162M quarterly profit and raises sales outlook

Vir shares NASDAQVIR closed at US$12.21 on Nasdaq at 4:00 p.m. EST on Nov. 6, according to Google Finance. That price predates Sunday's trial announcement and does not measure the market's response to it.

The Control Group Began Treatment At Week 12

ECLIPSE 1 randomized 124 adults, assigning 83 to monthly elebsiran and tobevibart and 41 to delayed treatment. The regimen consists of two separate sequential injections under the skin.

The different assessment times mean the headline result is not a comparison against an untreated group followed for the same duration. Vir's release identifies ECLIPSE 1 as a registrational trial in the United States and other regions where bulevirtide use is limited.

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The key secondary endpoint, undetectable virus alone, was reached by 79 per cent of treated patients at Week 48. The delayed-treatment group's rate was zero, with p below 0.0001.

Vir said most treatment-related adverse events were mild to moderate and transient. The Grade 3 event was a decrease in neutrophil count that resolved within 15 days; flu-like symptoms were the most common treatment-related event.

"For people living with CHD, the goal is not simply to reduce the amount of virus, but to drive it to levels where it is no longer detectable since ongoing HDV replication drives liver disease progression."

Nancy Reau, section chief of hepatology at Rush University Medical Center, made the comments in Vir's release.

Mirum Plans A Filing In The First Half Of 2027

Mirum Pharmaceuticals, Inc. NASDAQMIRM is pursuing the same disease with brelovitug, an investigational antibody targeting hepatitis B surface antigen. Its Sept. 28 release reported a positive primary endpoint in the Phase 3 portion of AZURE-1.

Brelovitug's weekly and monthly arms recorded response rates of 56 and 45 per cent, respectively, at Week 24. Its combined endpoint allowed at least a two-log viral-load reduction or undetectable virus alongside ALT normalization, unlike Vir's requirement for target-not-detected virus.

The separate studies therefore do not establish which regimen performs better. Mirum said it planned a biologics licence application in the first half of 2027.

For sector context, the iShares Biotechnology ETF NASDAQIBB closed at US$213.63 at 4:00 p.m. EST on Nov. 6, according to Google Finance.

Vir expects ECLIPSE 2 and ECLIPSE 3 data in the first quarter of 2027. The former evaluates switching patients inadequately suppressed on bulevirtide; the latter compares the combination directly with bulevirtide in patients not previously treated with it.

Vir will discuss the ECLIPSE 1 topline results and expanded SOLSTICE data on its Nov. 9 investor call.