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IgG4 Related DiseasePhase 3INDIGONCT05662241

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

A Phase 3 study testing Obexelimab in people with IgG4 Related Disease, run by Zenas BioPharma (USA), LLC at 65 sites in 15 countries.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

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

Who is it for?
Ages 18 years and older
Conditions the study is for
IgG4 Related Disease
What is being tested?
Obexelimab
Type of treatment
Injection or infusion
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
194 participants
Where
65 sitesin 15 countries
Study dates
9 Jan 2023to 15 Feb 2029
Phase
Phase 3
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Males and females, ≥ 18 years of age
  • Clinical diagnosis of IgG4-RD
  • Patients must meet the 2019 ACR/EULAR Classification Criteria for IgG4-RD
  • 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
  • Other inclusion criteria apply

Who cannot join

  • Has disease in only 1 organ system whose primary manifestation is fibrosis
  • Has received prednisone equivalent given orally at a dose greater than 60 mg/day within the 4 weeks prior to screening or during screening
  • Has received a non-biologic, disease-modifying anti-rheumatological drug or immunosuppressive agent other than GCs within the 2 weeks prior to screening
  • 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
  • Has received live vaccine or live therapeutic infectious agent within the 2 weeks prior to screening
  • Active tuberculosis or high risk for tuberculosis; hepatitis C infection in absence of curative treatment; evidence of hepatitis B infection
  • Use of B cell depleting or targeting agents within 6 months of randomization
  • Other exclusion criteria apply

Trial locations and contacts

65 sites in 15 countries.

65 sites in 15 countries

Japan20 sites

  • Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital

    Bunkyō-Ku, Tokyo

  • Kagawa University Hospital

    Hiragi, Kagawa-ken

  • Kansai Medical University Hospital

    Hirakata

  • Hiroshima University Hospital

    Hiroshima

  • Kanazawa University Hospital

    Kanazawa, Ishikawa-ken

  • St. Marianna University Hospital

    Kawasaki

  • Hospital of University of Occupational and Environmental Health

    Kitakyushu, Fukuoka, 807-8555

  • Kanazawa Medical University Hospital

    Kokura, Fukuoka

  • Shinshu University Hospital

    Matsumoto, Nagano, 390-8621

  • Tokyo Medical Center Hospital

    Meguro City

  • The Institute of Medical Science, The University of Tokyo Hospital

    Minato-ku, Tokyo

  • Nagaoka Red Cross Hospital

    Nagaoka

  • Nagasaki University Hospital

    Nagasaki

  • Kita-Harima Medical Center

    Ono

  • Osaka Metropolitan University Hospital

    Osaka, Osaka

  • Tazuke Kofukai Medical Research Institute Kitano Hospital

    Osaka

  • Sapporo Medical University Hospital

    Sapporo

  • Keio University Hospital

    Shinjuku-Ku, Tokyo

  • Fujita Health University Hospital

    Shinjuku-Ku

  • Toyama University Hospital

    Toyama, Toyama

Other trials in Japan

China9 sites

  • Chinese PLA General Hospital

    Beijing, Beijing Municipality

  • Peking Union Medical College Hospital

    Beijing, Beijing Municipality

  • Peking University First Hospital

    Beijing, Beijing Municipality

  • West China Hospital of Sichuan University

    Chengdu, Sichuan

  • Renji Hospital, Shanghai Jiaotong University School of Medicine

    Shanghai, Shanghai Municipality

  • The Second Hospital of Hebei Medical University

    Shijiazhuang, Hebei

  • Shanxi Bethune Hospital

    Taiyuan, Shanxi

  • Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology

    Wuhai, Hubei

  • Yantai Yuhuangding Hospital

    Yantai, Shandong

Other trials in China

United States5 sites

  • Emory Univeristy

    Atlanta, Georgia, 30322

  • Massachusetts General Hospital

    Boston, Massachusetts, 02114

  • Henry Ford Hospital

    Detroit, Michigan, 48202

  • GI PROS Research - Dedicated Research Facility

    Naples, Florida, 34102

  • Stanford Medicine

    Stanford, California, 94305

Other trials in United States

Italy5 sites

  • Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia

    Brescia, 25123

  • Azienda Ospedaliera Universitaria Meyer Istituto di Ricovero e Cura a Carattere Scientifico

    Florence

  • Ospedale San Raffaele S.r.l. - PPDS

    Milan

  • Ospedale San Giovanni Bosco

    Turin, Piedmont, 10128

  • University of Verona

    Verona, 37134

Other trials in Italy

France4 sites

  • Hôpital Beaujon

    Paris

  • Hôpital de la Pitié Salpétrière

    Paris

  • Haut-Lévèque Hospital Usn Building South Hospital Group

    Pessac, Bordeaux, 33604

  • Hôpitaux Universitaires de Marseille Timone

    Saint-Pierre, Marseille, 13005

Other trials in France

Spain4 sites

  • Hospital de la Santa Creu i Sant Pau

    Barcelona, 08025

  • Vall d'Hebron University Hospital

    Barcelona, 08035

  • Hospital Universitario Ramón y Cajal

    Madrid, Madrid, 28034

  • Hospital Universitario Virgen del Rocio

    Seville

Other trials in Spain

Canada3 sites

  • Center for Clinical Research (Nova Scotia Health)

    Halifax, Nova Scotia

  • Centre Hospitalier Universitaire de Sherbrooke CHUS

    Sherbrooke, Quebec

  • Artus Health Centre

    Vancouver, British Columbia

Other trials in Canada

Taiwan3 sites

  • Chang Gung Medical Foundation Kaohsiung Chang Gung Memorial Hospital

    Kaohsiung City

  • Taipei Veterans General Hospital

    Taipei

  • Linkou Chang Gung Memorial Hospital

    Taoyuan, 333

Other trials in Taiwan

Germany2 sites

  • LMU Klinikum der Universität München

    München, Bavaria

  • Universitätsklinikum Ulm

    Ulm

Other trials in Germany

Mexico2 sites

  • Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran

    Mexico City, Mexico City

  • Centro de Alta Especialidad En Reumatologia E Investigacion Del Potosi SC

    San Luis Potosí City

Other trials in Mexico

Poland2 sites

  • Szpital Uniwersytecki Nr 2 im. Dr Jana Biziela w Bydgoszczy

    Bydgoszcz

  • Narodowy Instytut Geriatrii, Reumatologii i Rehabilitacji im. Prof. Dr hab. Med. Eleonory Reicher

    Warsaw, Masovian Voivodeship

Other trials in Poland

South Korea2 sites

  • Seoul National University Hospital

    Seoul, Seoul, 03080

  • Ajou University Hospital

    Suwon, 206

Other trials in South Korea

Turkey (Türkiye)2 sites

  • Hacettepe University Faculty of Medicine

    Altındağ, Ankara, 06230

  • Marmara University Pendik Training and Research Hospital

    Pendik, Istanbul

Other trials in Turkey (Türkiye)

Argentina1 site

  • Hospital Italiano de Buenos Aires

    Buenos Aires

Other trials in Argentina

United Kingdom1 site

  • John Radcliffe Hospital

    Oxford

Other trials in United Kingdom

About this study

Official title: 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)

Read the 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).

Being tested
Obexelimab, Placebo
Keywords
IgG4, IgG4-RD
Medical subject headings
Immunoglobulin G4-Related Disease

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • ObexelimabDrug

    Obexelimab is a monoclonal antibody that co-engages CD19 and FcγRIIb to inhibit B cell activity

  • PlaceboOther

    Placebo

Study groups in NCT05662241
Study groupRoleWhat they receive
ZB012ExperimentalObexelimab administered as an SC injection.
Receives: Drug: Obexelimab
PlaceboPlacebo comparatorPlacebo administered as an SC injection.
Receives: Other: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Primary outcome measure

    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.

    Measured: Randomization to Week 52

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted22 Dec 2022
  2. Study start9 Jan 2023
  3. Primary completion13 Nov 2025
  4. Study completion15 Feb 2029 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 3
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
194 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05662241
Sponsor's protocol ID
ZB012-03-001
Acronym
INDIGO
Status last verified
Feb 2026
First submitted
14 Dec 2022
Last updated
4 Feb 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No

Publications

  • Della-Torre E, Baker MC, Zhang W, Perugino CA, Katz G, Tanaka Y, Khosroshahi A, Kleger A, Schleinitz N, Martinez-Valle F, Schulze-Koops H, Nakayamada S, Rebours V, Okazaki K, Dong L, Carruthers M, Chen LYC, Frulloni L, Meysami A, Takahashi H, Kawano M, Liu Y, Saeki T, Ebbo M, Alexander T, Gonzalez Garcia A, Karadag O, Maslinska M, Quinn SM, Poma A, Wells A, Greene TJ, Stone JH, Culver EL; INDIGO Trial Investigators. Obexelimab for the Treatment of IgG4-Related Disease. N Engl J Med. 2026 Jun 2. doi: 10.1056/NEJMoa2601337. Online ahead of print.

    PubMed 42233621

  • Culver EL, Baker MC, Della-Torre E, Zhang W, Perugino CA, Wells A, Mamuye A, Quinn SM, Poma A, Greene TJ, Stone JH. Efficacy and Safety of Obexelimab to Treat IgG4-Related Disease: Protocol for a Global, Randomized, Placebo-Controlled Trial. Rheumatol Ther. 2026 Jun;13(3):867-880. doi: 10.1007/s40744-026-00835-4. Epub 2026 Mar 16.

    PubMed 41840328

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Obexelimab in people with IgG4 Related Disease, run by Zenas BioPharma (USA), LLC at 65 sites in 15 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 4 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 65 sites in Japan, China, United States, Italy, France and 10 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Primary outcome measure (time frame: Randomization to Week 52). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05662241, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Feb 2026.

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