The primary objective of the study is to evaluate the safety of tobevibart+elebsiran in participants with chronic hepatitis Delta virus (HDV) infection. 

This research study is being done to learn more about chronic (long-term) hepatitis Delta virus (HDV) infection and whether the combination of study drugs, tobevibart (VIR-3434) and elebsiran (VIR-2218), can treat this infection as well as how an immediate treatment with the combination of study drugs compare to a delayed treatment in people with chronic HDV infection who are on nucleos(t)ide reverse transcriptase inhibitor (NRTI) therapy.

The Tobevibart and Elebsiran combination is experimental, which means that it is being tested and is not approved by the United States Food and Drug Administration (FDA).

The main procedures involve drug injection every 4 weeks, imaging scans, optional liver biopsy sub study.
   
Participants will be randomized into one of two treatment groups. In Study Arm 1, the total study duration is planned to be up to 271 weeks. In Study Arm 2, the total study duration may be up to 283 weeks.