A Phase 3 Study of Obexelimab in Patients With IgG4-Related Disease (INDIGO)

February 2, 2026 updated by: Zenas BioPharma (USA), LLC

A Phase 3, Multicenter, Randomized, Double-blind, Placebo-controlled Study to Evaluate the Efficacy and Safety of Obexelimab in Patients With IgG4-Related Disease (INDIGO)

This study aims to examine the efficacy and safety of obexelimab for the prevention of flare of IgG4-related disease (IgG4-RD)

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

This study consists of a 1-year randomized control period (RCP), followed by an additional 3-year open label extension (OLE) period.

To enter the Screening Period (Day -28 to Day -1), patients must have active IgG4-RD signs/symptoms (i.e., flare) that require steroid therapy. On Day 1, patients will be randomized in a ratio of 1:1 to receive either obexelimab or placebo administered as subcutaneous (SC) injections. All patients will begin a steroid taper on Day 1 to discontinuation by Week 8.

Patients will be monitored for flares during scheduled in clinic visits and any unscheduled visits. The primary endpoint is time to first IgG4-RD flare that requires initiation of rescue therapy in the opinion of the investigator and the Adjudication Committee (AC).

Following the 52-week RCP, patients will have the opportunity to continue in an OLE period where all patients will receive obexelimab. During the OLE, a subset of patients may be eligible to participate in a sub-study evaluating the immune response to vaccination while receiving obexelimab treatment. Patients who do not wish to enroll into the OLE period will return for an in-clinic safety follow-up visit 8 weeks after the Week 52 visit (i.e., Week 60).

Including screening and follow-up, the maximum duration of participation in this study for an individual patient is 224 weeks (i.e., 28-day screening, 52-week RCP, 156-week OLE, and a 12-week follow-up).

Study Type

Interventional

Enrollment (Actual)

194

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Argentina
      • Buenos Aires, Argentina
        • Hospital Italiano de Buenos Aires
  • Canada
    • British Columbia
      • Vancouver, British Columbia, Canada
        • Artus Health Centre
    • Nova Scotia
      • Halifax, Nova Scotia, Canada
        • Center for Clinical Research (Nova Scotia Health)
    • Quebec
      • Sherbrooke, Quebec, Canada
        • Centre Hospitalier Universitaire de Sherbrooke CHUS
  • China
    • Beijing Municipality
      • Beijing, Beijing Municipality, China
        • Chinese PLA General Hospital
      • Beijing, Beijing Municipality, China
        • Peking University First Hospital
      • Beijing, Beijing Municipality, China
        • Peking Union Medical College Hospital
    • Hebei
      • Shijiazhuang, Hebei, China
        • The Second Hospital of Hebei Medical University
    • Hubei
      • Wuhai, Hubei, China
        • Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology
    • Shandong
      • Yantai, Shandong, China
        • Yantai Yuhuangding Hospital
    • Shanghai Municipality
      • Shanghai, Shanghai Municipality, China
        • Renji Hospital, Shanghai Jiaotong University School of Medicine
    • Shanxi
      • Taiyuan, Shanxi, China
        • Shanxi Bethune Hospital
    • Sichuan
      • Chengdu, Sichuan, China
        • West China Hospital of Sichuan University
  • France
      • Paris, France
        • Hopital de La Pitie Salpetriere
      • Paris, France
        • Hôpital Beaujon
    • Bordeaux
      • Pessac, Bordeaux, France, 33604
        • Haut-Lévèque Hospital Usn Building South Hospital Group
    • Marseille
      • Saint-Pierre, Marseille, France, 13005
        • Hôpitaux Universitaires de Marseille Timone
  • Germany
      • Ulm, Germany
        • Universitätsklinikum Ulm
    • Bavaria
      • München, Bavaria, Germany
        • LMU Klinikum der Universität München
  • Italy
      • Brescia, Italy, 25123
        • Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia
      • Florence, Italy
        • Azienda Ospedaliera Universitaria Meyer Istituto di Ricovero e Cura a Carattere Scientifico
      • Milan, Italy
        • Ospedale San Raffaele S.r.l. - PPDS
      • Verona, Italy, 37134
        • University of Verona
    • Piedmont
      • Turin, Piedmont, Italy, 10128
        • Ospedale San Giovanni Bosco
  • Japan
      • Hirakata, Japan
        • Kansai Medical University Hospital
      • Hiroshima, Japan
        • Hiroshima University Hospital
      • Kawasaki, Japan
        • St. Marianna University Hospital
      • Meguro City, Japan
        • Tokyo Medical Center Hospital
      • Nagaoka, Japan
        • Nagaoka Red Cross Hospital
      • Nagasaki, Japan
        • Nagasaki University Hospital
      • Ono, Japan
        • Kita-Harima Medical Center
      • Osaka, Japan
        • Tazuke Kofukai Medical Research Institute Kitano Hospital
      • Sapporo, Japan
        • Sapporo Medical University Hospital
      • Shinjuku-Ku, Japan
        • Fujita Health University Hospital
    • Fukuoka
      • Kitakyushu, Fukuoka, Japan, 807-8555
        • Hospital of University of Occupational and Environmental Health
      • Kokura, Fukuoka, Japan
        • Kanazawa Medical University Hospital
    • Ishikawa-ken
      • Kanazawa, Ishikawa-ken, Japan
        • Kanazawa University Hospital
    • Kagawa-ken
      • Hiragi, Kagawa-ken, Japan
        • Kagawa University Hospital
    • Nagano
      • Matsumoto, Nagano, Japan, 390-8621
        • Shinshu University Hospital
    • Osaka
      • Osaka, Osaka, Japan
        • Osaka Metropolitan University Hospital
    • Tokyo
      • Bunkyō-Ku, Tokyo, Japan
        • Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital
      • Minato-ku, Tokyo, Japan
        • The Institute of Medical Science, The University of Tokyo Hospital
      • Shinjuku-Ku, Tokyo, Japan
        • Keio University Hospital
    • Toyama
      • Toyama, Toyama, Japan
        • Toyama University Hospital
  • Mexico
      • San Luis Potosí City, Mexico
        • Centro de Alta Especialidad En Reumatologia E Investigacion Del Potosi SC
    • Mexico City
      • Mexico City, Mexico City, Mexico
        • Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran
  • Poland
      • Bydgoszcz, Poland
        • Szpital Uniwersytecki nr 2 im. Dr Jana Biziela w Bydgoszczy
    • Masovian Voivodeship
      • Warsaw, Masovian Voivodeship, Poland
        • Narodowy Instytut Geriatrii, Reumatologii i Rehabilitacji im. prof. dr hab. med. Eleonory Reicher
  • South Korea
      • Suwon, South Korea, 206
        • Ajou University Hospital
    • Seoul
      • Seoul, Seoul, South Korea, 03080
        • Seoul National University Hospital
  • Spain
      • Barcelona, Spain, 08025
        • Hospital de la Santa Creu i Sant Pau
      • Barcelona, Spain, 08035
        • Vall d'Hebrón University Hospital
      • Seville, Spain
        • Hospital Universitario Virgen Del Rocio
    • Madrid
      • Madrid, Madrid, Spain, 28034
        • Hospital Universitario Ramon y Cajal
  • Taiwan
      • Kaohsiung City, Taiwan
        • Chang Gung Medical Foundation Kaohsiung Chang Gung Memorial Hospital
      • Taipei, Taiwan
        • Taipei Veterans General Hospital
      • Taoyuan District, Taiwan, 333
        • Linkou Chang Gung Memorial Hospital
  • Turkey (Türkiye)
    • Ankara
      • Altındağ, Ankara, Turkey (Türkiye), 06230
        • Hacettepe University Faculty of Medicine
    • Istanbul
      • Pendik, Istanbul, Turkey (Türkiye)
        • Marmara University Pendik Training and Research Hospital
  • United Kingdom
      • Oxford, United Kingdom
        • John Radcliffe Hospital
  • United States
    • California
      • Stanford, California, United States, 94305
        • Stanford Medicine
    • Florida
      • Naples, Florida, United States, 34102
        • GI PROS Research - Dedicated Research Facility
    • Georgia
      • Atlanta, Georgia, United States, 30322
        • Emory Univeristy
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Massachusetts General Hospital
    • Michigan
      • Detroit, Michigan, United States, 48202
        • Henry Ford Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Males and females, ≥ 18 years of age
  2. Clinical diagnosis of IgG4-RD
  3. Patients must meet the 2019 ACR/EULAR Classification Criteria for IgG4-RD
  4. Patients must have active IgG4-RD signs/symptoms (i.e., flare) that require the initiation of GC therapy or the increase in background long-term GC therapy
  5. Other inclusion criteria apply

Exclusion Criteria:

  1. Has disease in only 1 organ system whose primary manifestation is fibrosis
  2. Has received prednisone equivalent given orally at a dose greater than 60 mg/day within the 4 weeks prior to screening or during screening
  3. Has received a non-biologic, disease-modifying anti-rheumatological drug or immunosuppressive agent other than GCs within the 2 weeks prior to screening
  4. Has received an investigational treatment or direct medical intervention on another clinical study within 12 weeks or < 5 half-lives of the investigational treatment, whichever is shorter, prior to screening
  5. Has received live vaccine or live therapeutic infectious agent within the 2 weeks prior to screening
  6. Active tuberculosis or high risk for tuberculosis; hepatitis C infection in absence of curative treatment; evidence of hepatitis B infection
  7. Use of B cell depleting or targeting agents within 6 months of randomization
  8. Other exclusion criteria apply

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: ZB012
Obexelimab administered as an SC injection.
Drug: Obexelimab
Obexelimab is a monoclonal antibody that co-engages CD19 and FcγRIIb to inhibit B cell activity
Placebo Comparator: Placebo
Placebo administered as an SC injection.
Other: Placebo
Placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Primary outcome measure
Time Frame: Randomization to Week 52
Time to first IgG4-RD flare, defined as the reappearance of previous signs/symptoms or appearance of new signs/symptoms of IgG4-RD that requires initiation of rescue therapy in the opinion of the investigator and the Adjudication Committee (AC), from randomization to Week 52.
Randomization to Week 52

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Vaccine antibody titers
Time Frame: During the 3 year OLE period
Vaccine antibody titers at multiple timepoints post-vaccination
During the 3 year OLE period

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Zenas BioPharma (USA), LLC

Collaborators

Bristol-Myers Squibb

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 9, 2023

Primary Completion (Actual)

November 13, 2025

Study Completion (Estimated)

February 15, 2029

Study Registration Dates

First Submitted

December 14, 2022

First Submitted That Met QC Criteria

December 14, 2022

First Posted (Actual)

December 22, 2022

Study Record Updates

Last Update Posted (Actual)

February 4, 2026

Last Update Submitted That Met QC Criteria

February 2, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ZB012-03-001

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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