An experimental two-drug combination from Vir Biotechnology has succeeded in the first of three Phase 3 trials against chronic hepatitis D, the company said Sunday.
Vir’s drugs, “elebsiran” and “tobevibart,” met their main objective in the study by largely eliminating detectable signs of the virus and normalizing levels of an important liver enzyme in 44% of treatment participants after 48 weeks. By comparison, none in a “delayed treatment” cohort achieved those results, according to Vir.
The regimen also met a key secondary endpoint focused solely on dropping viral levels, with 79% of treated patients achieving a treatment response.
Two additional Phase 3 trials are ongoing and should produce data early next year. Results from all three studies, if positive, would support a regulatory submission in 2027.
Vir was initially formed to go after infectious diseases and, in 2021, successfully brought to market a COVID-19 antibody drug called Xevudy. But the company has since restructured and changed course. It’s now primarily working on T-cell engagers for cancer.
Vir clung to some of its infectious disease research, however. Even after its transition, the company kept pursuing preclinical HIV research and a pivotal-stage program in hepatitis D.
Hepatitis D is a liver infection that only occurs in people who have already contracted the hepatitis B virus. People can either be infected by both viruses at the same time or get a “superinfection” when hepatitis D gets into the body after hepatitis B. The latter situation is linked to long-term illness, such as liver scarring and organ failure, according to the Centers for Disease Control and Prevention.
The condition is uncommon in the U.S., but is believed by the World Health Organization to affect 5% of people with chronic hepatitis B infections worldwide.
There are limited treatment options for chronic hepatitis D infections, but the landscape could be quickly changing. Earlier this year, the Food and Drug Administration made Gilead Sciences’ Hepcludex, a once-daily injection, the first approved treatment in the U.S. for chronic hepatitis D. And in September, a drug Mirum Pharmaceuticals acquired in a buyout succeeded in a Phase 3 trial.
In a Monday note to clients, Evercore ISI analyst Cory Kasimov predicted that Vir’s drug combination should become the “preferred” medicine for hepatitis D and has the “potential to become a dominant front-line product upon approval.”
Kasimov added that the drug’s results compared favorably to the data Gilead and Mirum have presented for their rival therapies.
“Cross-trial caveats apply, but the gap is wide,” he added.
Vir shares climbed by about 12% in early Monday trading.
