Safety and Antiviral Activity of a Monoclonal Hepatitis B Antibody: a Phase 1b, Open-label Trial in Individuals With Chronic Hepatitis D Infection

NCT07610772 | Recruiting Phase 1 DMC

• 2 other identifiers: SAMBA-D-0012025-522125-36-00
• Study Type: interventional
• Target: 15
• Locations: 2 countries
• Sites: 2

Brief Summary

Hepatitis D virus (HDV) is a major global health issue, with an estimated 12 million people living with the infection worldwide. HDV infection requires the presence of hepatitis B virus (HBV), as it relies on hepatitis B virus for replication within the liver cells. Treatment options for HDV are limited and cannot cure the infection. The combination of concurrent HBV and HDV increases the risk of developing severe liver disease, including cirrhosis and liver cancer. This risk would significantly decrease if HDV is eliminated or reduced. Consequently, there is a need for the development of new treatment options. Colleagues at Rockefeller University in New York have identified the antibody HepB mAb19, which effectively reduces the amount of circulating HBV antigens. Since HDV depends on HBV to replicate, we will test this antibody as a potential treatment for HDV. The trial design is a phase 1b open-label aiming at including 15 study participants with chronic hepatitis D infection. All study participants will receive two or three dosis of the antibody, HepB mAB19, and will be followed for 60 weeks after the first HepB mAb19 infusion. This study will evaluate the safety and pharmacokinetics of this antibody, as well as its potential effects on viral levels of HDV RNA and antiviral immune responses in individuals living with chronic HDV infection.

Conditions

Hepatitis D, Chronic; Hepatitis B Chronic Infection

Keywords

SAMBA-D; 2025-522125-36-00 (EU CT no.)

Outcome Measures

Primary Outcomes (10)

• Safety and tolerability

  Rate and severity of solicited adverse events that are Grade 2 or above

  Two weeks after each administration

• Safety and tolerability

  Rate and severity of treatment-emerging unsolicited adverse events (including confirmed laboratory abnormalities) 2, 12, 28 and 60 weeks after first HepB mAb19 administration.

  2, 12, 28 and 60 weeks after first HepB mAb19 administration

• Safety and tolerability

  Rate and severity of serious adverse events (SAEs) throughout the study period following investigational product (IP) administration

  From enrollment to end of follow-up at week 60

• Safety and tolerability

  Rate and severity of adverse events of special interest, such as immune complex disease (ICD) throughout the study period following IP administration.

  From enrollment to end of follow-up at week 60

• Pharmacokinetic profile

  HepB mAb19 levels in serum will be measured by a validated sandwich ELISA method developed and performed by Celldex Therapeutics. HepB mAb19 levels will be measured before and at the end of each of the antibody administrations, at 3 and 6 hours, and at later time points during follow up.

  From enrollment to end of follow-up at week 60

• Pharmacokinetic profile

  Assesment of HepB mAb19 elimination half-life (t1/2)

  From enrollment to end of follow-up at week 60

• Pharmacokinetic profile

  Assesment of clearance (CL/F) of HepB mAb19

  From enrollment to end of follow-up at week 60

• Pharmacokinetic profile

  Calculation of volume of distribution (Vz/F)

  From enrollment to end of follow-up at week 60

• Pharmacokinetic profile

  Calculation of area under the curve (AUC) for HepB mAb19

  From enrollment to end of follow-up at week 60

• Pharmacokinetic profile

  Calculation of HepB mAb19 decay curve

  From enrollment to end of follow-up at week 60

Secondary Outcomes (3)

• Virologic response

  From baseline (day 0) to week 28

• Anti-drug antibodies

  From enrollment to end of follow-up at week 60

• Changes in liver function tests

  From enrollment to end of follow-up at week 60

Other Outcomes (5)

• HBV markers

  From enrollment to end of follow-up at week 60

• HDV markers

  From enrollment to end of follow-up at week 60

• Innate immune response

  From enrollment to end of study at week 60

Study Arms (1)

Opel label

EXPERIMENTAL

All participants will be included in this study arm

Drug: HepB mAb19

Interventions

HepB mAb19 DRUG

All participants will receive a dose of HepB mAb19 at day 0 of 10 mg/kg and at day 28 of 30 mg/kg. They will receive a third dose at day 140 of 30 mg/kg if we observe a 1-log decrease in HDV RNA from week 0 to week 6.

Opel label

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• HDV infection confirmed by positive anti-HDV antibody and detectable HDV RNA
• HBs antibody negative during screening period
• Both HBeAg positive and negative participants are included
• Ability and willingness to provide informed consent
• Participants who can become pregnant must agree to use two methods of contraception:
• Participants who can impregnate a partner and who are engaging in sexual activity that could lead to pregnancy must agree to use condoms 10 days prior to study entry and during study follow up to avoid impregnating a partner who can get pregnant.

You may not qualify if:

• Child-Turcotte-Pugh \>9 points
• Severe clinical hepatic decompensation-such as hepatic encephalopathy or variceal hemorrhage-occurring currently or within the past 12 months.
• Any confirmed significant allergic reactions (urticaria or anaphylaxis) against monoclonal antibody or vaccine, or multiple drug allergies (non-active hay fever is acceptable)
• Pregnancy or lactation
• Any vaccination 2 weeks prior to entry
• Prior receipt of HepB mAb19 therapy
• Any significant acute infection (e.g. influenza, COVID-19) or any other clinically significant illness 2 weeks prior to entry
• Active hepatitis C infection
• Untreated HIV disease
• Individuals with HIV receiving antiretroviral therapy who have had a measurement of plasma HIV RNA (viral load) \>50 copies/mL within the past 6 months are excluded. However, a single viral load measurement between \>50 and \<500 copies/mL during this period is acceptable.
• Participation in another clinical study of an investigational product currently or 12 weeks prior to entry, or expected participation during this study
• Laboratory abnormalities in the parameters listed below:
• Alpha fetoprotein \>100 ng/mL
• Hemoglobin \<10 gm/dL (6.21 mmol/L)
• Platelet count \<25,000 /mm3

Sponsors & Collaborators

• Aarhus University Hospital: lead
• Charite University, Berlin, Germany: collaborator

Study Sites (2)

Aarhus University Hospital

Aarhus, 8000, Denmark

RECRUITING

Charité - Universitätsmedizin Berlin

Berlin, Germany

NOT YET RECRUITING

MeSH Terms

Conditions

Hepatitis D, Chronic

Condition Hierarchy (Ancestors)

Hepatitis D; Hepatitis, Viral, Human; Virus Diseases; Infections; RNA Virus Infections; Hepatitis, Chronic; Hepatitis; Liver Diseases; Digestive System Diseases; Chronic Disease; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Central Study Contacts

Ole Schmeltz Søgaard, MD, PhD, professor

CONTACT

+45 24 77 79 95; olesoega@rm.dk

Henriette Vendelbo Graversen, MD

CONTACT

+45 51 49 25 95; henrgv@rm.dk

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor, MD, PhD

Study Record Dates

• First Submitted: May 12, 2026
• First Posted: May 28, 2026
• Study Start: April 23, 2026
• Primary Completion (Estimated): April 1, 2028
• Study Completion (Estimated): April 1, 2028
• Last Updated: May 28, 2026

Record last verified: 2026-05

Locations

DK (1); DE (1)