Drug Watch
Drugs in Development for Hepatitis Delta:
Drug |
Mechanism |
Company |
Clinical Trial Phase |
Status & Designations |
Hepcludex (Bulevirtide) (Formerly Myrcludex B)
|
Entry Inhibitor |
Gilead Sciences, Inc. |
Ongoing Observational and Patient Registry trials |
Approved by the U.S. FDAApproved in the EU and the UK
|
Brelovitug |
Monoclonal Antibody |
Mirum Pharma |
Phase III (recruiting) |
Orphan drug and EMA PRIME designationFDA Breakthrough Therapy Designation |
Jitixib® (Lonafarnib) |
Prenylation Inhibitor |
EIT Pharma
|
Phase III |
N/A |
Peg-interferon lambda-1a (Lambda) |
Immune modulator |
EIT Pharma
|
Phase II |
Lambda currently on clinical hold by FDA |
REP 2139 - Mg (in combination with PEG-IFN and Tenofovir) |
HBsAg Inhibitor |
Replicor, Canada |
Phase II (planned enrollment starting in France)
|
N/A |
Brelovitug (formerly BJT-778) |
Monoclonal antibody |
Mirum Pharma
|
mirumpharma.com |
Phase II/III |
Tobevibart + Elebsiran |
SiRNA Immune Response Stimulator/HBsAg Inhibitor/Entry Inhibitor |
Vir Biotechnology |
Phase III (recruiting outside the U.S.) |
EMA PRIME designationFDA Breakthrough Therapy Designation and Fast Track Designation |
HH-003 (Libevitug) |
Anti-PreS1 IgG1 monoclonal Ab, entry Inhibitor |
Huahui Health |
Phase IIb/III (recruiting by invitation) |
FDA and NMPA Breakthrough Therapy DesignationConditional approval by NMPA |
Hepalatide |
NTCP Target |
Shanghai HEP Pharmaceuticals |
Phase lll (not yet recruiting) |
N/A |
RBD1016 |
Short interfering RNA (siRNA) agent |
Ribocure Pharmaceuticals AB |
Phase II (Active, not recruiting) |
N/A |
Ropeginterferon Alpha 2b (P1101) & anti-PD1 |
Small Molecule Entry Inhibitor |
PharmaEssentia |
Phase Ib (complete) |
N/A |
HDV pre-S1 nAb (GS-4321) |
Entry inhibitor |
Gilead Sciences, Inc. |
Phase l/ll (recruiting) |
N/A |
ABI-6250 & Interferon Alpha Receptor Agonist |
Small Molecule Entry Inhibitor |
Assembly BioSciences |
Phase I (complete) |
N/A |
GI-18000 |
Immune Response Stimulator |
GlobeImmune, USA |
Preclinical |
N/A |
HH - 1270 |
NTCP inhibitor |
Huahui Health |
Preclinical |
N/A |
Chart Updated May 2026
Glossary:
Terms: HBV = Hepatitis B Virus, CHB = Chronic Hepatitis B, HDV = Hepatitis Delta Virus, CHD = Chronic Hepatitis Delta, PEG-IFN = Pegylated Interferon, NTCP = Sodium/Taurocholate Co-transporting Polypeptide, HBsAg = Hepatitis B Surface Antigen, RNA = Ribonucleic Acid, SiRNA = Small Interfering RNA (a strand of synthetic RNA designed to specifically target a particular messenger RNA for destruction), FDA = U.S. Food and Drug Administration, EMA = European Medicines Agency, NIH = National Institutes of Health, British MHRA = Great Britain Medicines and Healthcare products Regulatory Agency, NMPA = National Medical Products Administration, PRIME = PRIority MEdicines by EMA.
Hepcludex (Bulevirtide) (formerly Myrcludex B)
Hepcludex (generic name bulevirtide) is an “entry inhibitor” that works by stopping the hepatitis delta virus from entering and infecting hepatocytes (liver cells) and breaking the cycle of reinfection. Hepcludex was approved by the U.S. FDA in May 2026 for treatment of chronic hepatitis delta in adults without cirrhosis or with compensated cirrhosis. The drug achieved its endpoints based on reductions in HDV RNA and normalization of alanine aminotransferase (ALT), during the pivotal, controlled Phase 3 MYR301 study. At Week 48, the study demonstrated a statistically significant improvement versus the control (delayed treatment) group in a combined virologic and biochemical response.
In April of 2023, the drug was approved for prescription in the wider European Union and the UK, and it has also since been approved for prescription in Switzerland. Studies have also shown promise for Hepcludex when combined with PEG-IFN in reducing hepatitis delta viral levels. These studies have shown the achievement of significant response for HDV at 48 weeks. This drug has been granted PRIME Eligibility by the EMA, Breakthrough Therapy and Orphan Drug Designation by the FDA, and Promising Innovative Medicine Designation by the British MHRA.
Interferon Alpha (IFN-α)
Pegylated interferon alpha has been used as an off-label treatment for CHD since 1980. Viral response rates typically range between 25 and 30% with this treatment. International guidelines recommend a treatment duration of 48 weeks. A high relapse rate and severe side effects with IFN-α make the study of alternative treatments timely and critical.
Lonafarnib + Ritonavir
Lonafarnib is a "prenylation inhibitor" and works by targeting the protein assembly process, which prevents new virus cells from being created. Lonafarnib combined with ritonavir has shown promise in reducing hepatitis delta virus levels. Eiger Biopharmaceuticals has completed their Phase III D-LIVR clinical trial and topline data looks promising. The LOWR6 study, which is also investigating use of lonafarnib and ritonavir for treatment of hepatitis delta, is also currently in phase 3 trials (no longer recruiting). Lonafarnib has been granted Fast Track Designation and Breakthrough Therapy Designation by the FDA, PRIME Eligibility Designation by the EMA, and Orphan Drug Designation by the FDA and EMA.
Brelovitug (BJT-778)
BJT-778 is a monoclonal antibody against hepatitis B surface antigen (anti-HBsAg mAb). This drug neutralizes and clears hepatitis B and hepatitis D virions and depletes HBsAg-containing subviral particles, which may help to reconstitute an individual’s antiviral immunity and contribute to functional cure for chronic hepatitis B. The drug is in Phase IIb/III clinical trials and has recently received EMA PRIME designation and FDA Breakthrough Therapy Designation.
REP 2139-Mg
REP 2139-Mg is a "nucleic acid-based amphipathic polymer (NAP)" that works by preventing infected liver cells from releasing hepatitis B virus into healthy liver cells. It is being evaluated for use in combination with PEG-IFN and Tenofovir. A study indicated that this combination treatment lowered HBsAg levels, HBV DNA, and HDV RNA in some patients. Planning for Phase II trials for this drug in France is currently in progress and enrollment is planned for 2025.
Tobevibart & Elebsiran (Vir-3434 & Vir-2218)
Elebsiran is an HBV-targeted SiRNA that has the potential to stimulate an effective immune response and demonstrate direct antiviral activity against HBV and HDV. Tobevibart is a monoclonal antibody that targets HBsAg and is designed to remove HBV and HDV from the blood and block the entry of these viruses into liver cells. A phase 2 study of both of these drugs is currently recruiting participants, as is a Phase 3 study. Tobevibart & Elebsiran recently received the EMA PRIME and FDA Breakthrough Therapy Designations.
HH-003
HH-003 is a novel entry inhibitor for HBV & HDV. It has the potential to become a new standard of care that offers functional cure, stand-alone or in combination with other therapeutics, for patients suffering from chronic HBV infection or HBV/HDV co-infection. A phase 2 study for HH-003 is now complete. HH-003 recently received the FDA Breakthrough Therapy Designation.
Hepalatide
Hepalatide works by targeting NTCP (Sodium/Taurocholate Co-transporting Polypeptide). A Phase 2 study to evaluate efficacy in people living with chronic hepatitis D is now complete and a Phase 3 study is planned to begin in 2026.
RBD1016
RBD1016 helps treat HDV by reducing the amount of HDV RNA that is bound to it as a siRNA. A Phase 2 study to evaluate this drug is currently active (but not recruiting participants).
ABI-6250 & Interferon Alpha Receptor Agonist
These drugs are both in development by Assembly Biosciences and will work to prevent HDV and HBV from entering healthy liver cells by blocking receptor mechanisms on the healthy cells. A Phase 1 study to evaluate this drug is now complete.
Ropeginterferon Alpha 2b (P1101) & anti-PD1
P1101 is a long-acting interferon that can stimulate the liver to produce a special protein, which can inhibit the entry and replication of hepatitis B virus in liver cells and reduce damage. P1101 is an optimized form of long acting interferon that allows for dosing once every two weeks. It is expected to be helpful in slowing down or stopping the progression of hepatitis B or hepatitis D. A phase 1b trial of this drug was completed in July of 2025.
GI-18000
GI-18000 is an "immune response stimulator" that works by causing the host's T-cells to target and fight the infected liver cells.
Updated May 2026