Vir Biotechnology's elebsiran and tobevibart combination meets goals in first Phase 3 hepatitis D trial

Vir Biotechnology reported that its experimental two-drug combination, elebsiran and tobevibart, met the main objective of the first of three Phase 3 trials in chronic hepatitis D, according to biopharmadive.com biopharmadive.combiopharmadive.combiopharmadive.comOpen source ↗. The company announced the result on Sunday. After 48 weeks, 44% of treated participants had largely undetectable virus and normalized levels of an important liver enzyme. In the delayed-treatment cohort, none achieved this result, according to Vir.

The regimen also met a key secondary endpoint that looked only at reduction of viral levels: 79% of treated patients had a treatment response, the company said.

Trial timeline

Two additional Phase 3 trials are ongoing, and their data are expected early next year. If the results of all three studies are positive, they would support a regulatory submission in 2027.

Hepatitis D and the treatment landscape

Hepatitis D is a liver infection that occurs only in people who have already contracted the hepatitis B virus. A person can be infected with both viruses at the same time or develop a superinfection, when hepatitis D enters the body after hepatitis B. The latter is linked to long-term illness such as liver scarring and organ failure, according to the U.S. Centers for Disease Control and Prevention biopharmadive.combiopharmadive.combiopharmadive.comOpen source ↗.

The condition is uncommon in the U.S. The World Health Organization believes it affects 5% of people with chronic hepatitis B infections worldwide.

Treatment options for chronic hepatitis D are limited. Earlier this year the U.S. Food and Drug Administration made Gilead Sciences' Hepcludex, a once-daily injection, the first approved treatment for chronic hepatitis D in the U.S. In September, a drug acquired by Mirum Pharmaceuticals succeeded in a Phase 3 trial.

Vir was initially formed to work on infectious diseases and in 2021 brought to market the COVID-19 antibody drug Xevudy. The company has since restructured and now works primarily on T-cell engagers for cancer. It kept preclinical HIV research and the pivotal-stage hepatitis D program biopharmadive.combiopharmadive.combiopharmadive.comOpen source ↗.