Testing a new monoclonal antibody for chronic hepatitis B infection

A Phase 1, Placebo-controlled, Dose-escalation Study of the Safety, Pharmacokinetics, and Antiviral Activity of a Potent Neutralizing Monoclonal Antibody in Individuals With Chronic Hepatitis B Infection

Phase 1 Interventional Rockefeller University · NCT05856890

This study is testing a new antibody treatment for people with chronic hepatitis B to see if it can help improve their condition while they are already on other medications.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment37 (estimated)
Ages18 Years to 70 Years
SexAll
SponsorRockefeller University Academic / other
Locations2 sites (New York, New York and 1 other locations)
Trial IDNCT05856890 on ClinicalTrials.gov

What this trial studies

This phase 1 clinical trial evaluates the safety, pharmacokinetics, and antiviral activity of a novel monoclonal antibody, HepB mAb19, in individuals with chronic hepatitis B infection who are already on nucleos(t)ide analog therapy. Participants will be randomly assigned to receive either the antibody or a placebo in a dose-escalation format, with doses ranging from 1 mg/kg to 30 mg/kg. The study aims to assess the effects of a single intravenous infusion of HepB mAb19 over a follow-up period of 48 weeks.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 to 70 with chronic hepatitis B infection who have been on stable nucleos(t)ide therapy for at least six months.

Not a fit: Patients who are not on nucleos(t)ide therapy or have other forms of hepatitis or liver disease may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a new therapeutic option for individuals with chronic hepatitis B, potentially improving their viral control.

How similar studies have performed: While this approach is novel, other studies involving monoclonal antibodies for viral infections have shown promise, indicating potential for success.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age 18 to 70;
* HBV infection confirmed by positive HBsAg for \>/= 6 months;
* On HBV-active nucleos(t)ide therapy for \>/= 6 months without change in NRTI in the previous 3 months;
* The following laboratory values within 49 days from study entry (day 0):
* HBV DNA below lower limit of quantification;
* HBsAg \> 10 IU/mL;
* HBs antibody negative;
* Ability and willingness to provide informed consent;
* For participants who can become pregnant (i.e., participants who have not been post-menopausal for at least 24 consecutive months, who have had menses within the preceding 24 months, or who have not undergone surgical sterilization, specifically hysterectomy and/or bilateral oophorectomy or bilateral salpingectomy), negative serum or urine pregnancy test at screening and on day 0 (study entry).
* Participants who can become pregnant must agree to use two methods of contraception.
* Partner sterilization with documentation of azoospermia prior to the participant's entry into the study, and this partner is the sole partner for that participant. The documentation of partner sterility can come from the site personnel's review of medical records or medical history interview provided by the participant or the partner. Self-reported documentation of reproductive potential should be entered in the source documents.
* Participants who can impregnate a partner and who are engaging in sexual activity that could lead to pregnancy must agree to use condoms from 10 days prior to study entry and during study follow up to avoid impregnating a partner who can get pregnant.

Exclusion Criteria:

\- Clinical symptoms, imaging studies or liver histology suggestive of advanced fibrosis (exclude fibrosis grade 3 and 4 by FibroScan (Fibroscan®\< 9 kpa) within 12 months from entry or done at the pre-infusion visit.

Note: If FibroScan results from within 12 months are not available, imaging will be performed at the pre-infusion visit.

* Presence of a LI-RADS4 or 5 liver lesion on imaging within 12 months from entry or done at pre-infusion visit, if prior results not available.
* Alpha fetoprotein \> 20 ng/ml Note: AFP above normal but \< 20 is acceptable for entry if earlier AFP levels (older than 6 months) are within normal range and imaging is negative in last 3 months).
* HIV-1, HCV or hepatitis delta virus infection within 12 months from entry or done at screen, if prior results not available.
* History of hematopoietic stem cell transplant or solid organ transplant;
* Any confirmed significant allergic reactions (urticaria or anaphylaxis) against any drug, monoclonal antibody or vaccine, or multiple drug allergies (non-active hay fever is acceptable);
* History of cardiovascular disease (e.g., cardiac insufficiency, coronary artery disease, cardiomyopathy, congestive heart failure, family history of congenital long QT syndrome, family history of sudden death);
* History or presence of clinically significant ECG abnormalities based on the average of the triplicate ECG recordings (e.g., QT corrected for heart rate using the Fridericia's correction factor \[QTcF\] \> 450 ms for males and QTcF \> 470 ms for females);
* History of systemic corticosteroids, immunosuppressive anti-cancer, systemic interferons or interleukins within the last 6 months;
* History of chronic liver disease from another cause, immune complex disease, or autoimmune diseases that in the opinion of the investigator would preclude participation.
* Any significant acute infection (e.g. influenza, COVID-19) or any other clinically significant illness within 2 weeks prior to Day 0.
* Laboratory abnormalities in the parameters listed below:
* Absolute neutrophil count \< 1,000 /mm3
* Hemoglobin \< 10 gm/dL
* Platelet count \< 150,000 /mm3
* ALT \> 2.0 x ULN
* AST \> 2.0 x ULN
* Total bilirubin \> 1.5 ULN (except individuals with known Gilbert's)
* Albumin \< 3.5 gm/dL
* Calculated creatinine clearance \< 70 mL/min (using the Cockcroft Gault formula).
* INR \>/= 1.2
* Pregnancy or lactation;
* Any vaccination within 14 days prior to IP administration;
* Receipt of anti-HBV mAb therapy of any kind in the past (including HBIG);
* Participation in another clinical study of an investigational product currently or within past 12 weeks, or expected participation during this study.

Where this trial is running

New York, New York and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Hepatitis b VirusHepatitis Bmonoclonal antibodyHBVHepB mAb19
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.