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Study on the Effects of Obexelimab for Patients with IgG4-Related Disease

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying a condition known as IgG4-Related Disease, which is a rare disorder that can cause inflammation in various parts of the body. The study is testing a treatment called Obexelimab, which is given as an injection under the skin. The purpose of the study is to evaluate how effective and safe Obexelimab is for patients with this disease.

Participants in the study will receive either Obexelimab or a placebo, which is a solution that looks like the treatment but does not contain the active medicine. The study will last for about a year, during which participants will receive weekly injections. The study aims to see if Obexelimab can help prevent flare-ups of the disease, which are times when symptoms get worse.

Throughout the study, the safety and tolerability of Obexelimab will be closely monitored. This means that researchers will keep track of any side effects or health changes that occur. The study will also look at how often flare-ups happen and how much additional treatment is needed to manage them. Participants will have regular check-ups to assess their health and the effects of the treatment.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial Glucocorticoid Treatment Phase

    Upon joining the study, the patient will begin an initial course of treatment with glucocorticoids (also known as GC). Glucocorticoids are medications that reduce inflammation in the body.

    This initial treatment phase is designed to control the active symptoms of IgG4-Related Disease (a rare condition where the immune system causes inflammation in various organs).

  2. Step 2

    Randomization to Treatment Groups

    After completing the initial glucocorticoid treatment, the patient will be randomly assigned to one of two treatment groups. This process is called randomization, and it works like a coin toss to determine which treatment the patient will receive.

    Neither the patient nor the study doctor will know which treatment group the patient is in. This is called a double-blind study design.

    The patient will receive either obexelimab (the medication being tested) or a placebo (an inactive substance that looks like the real medication but contains no active drug).

  3. Step 3

    Weekly Injections for 52 Weeks

    The patient will receive weekly injections under the skin (called subcutaneous injections or SC injections) for a period of 52 weeks (approximately one year).

    If assigned to the obexelimab group, each injection will contain 250 mg of obexelimab.

    If assigned to the placebo group, each injection will contain a sterile solution without any active medication.

    These injections will be administered once every week throughout the entire 52-week period.

  4. Step 4

    Regular Monitoring and Assessments

    Throughout the 52-week treatment period, the patient will attend regular study visits for monitoring and assessment.

    During these visits, the study doctor will check for any signs of disease flare (when previous symptoms return or new symptoms appear).

    The patient's condition will be evaluated using the IgG4-RD Responder Index (a scoring system that measures disease activity).

    The study team will monitor for any adverse events (unwanted or harmful reactions) and serious adverse events (more severe medical problems that may require hospitalization or medical attention).

  5. Step 5

    Rescue Therapy if Needed

    If the patient experiences a disease flare during the study, the study doctor may decide that rescue therapy is needed. Rescue therapy refers to additional treatment (typically glucocorticoids) given to control the flare.

    The decision to start rescue therapy will be made by both the study doctor and an independent Adjudication Committee (a group of medical experts who review the patient's condition).

    If rescue therapy is required, the amount and timing of this additional medication will be recorded as part of the study.

  6. Step 6

    Completion of Treatment Period at Week 52

    After completing the full 52 weeks of weekly injections, the patient will reach the end of the main treatment period.

    At this final visit (Week 52), the study doctor will perform a comprehensive assessment to determine if the patient has achieved complete remission. Complete remission means there has been no disease flare, no need for rescue therapy, and either no signs of active disease or a score of 0 on the IgG4-RD Responder Index.

    The study team will review all safety information collected throughout the treatment period.

Who can join the trial?

13 criteria

  • You must be at least 18 years old
  • You must have a clinical diagnosis of IgG4-Related Disease, which is a rare condition where your immune system causes inflammation and damage in various organs
  • You must meet specific classification criteria established by medical organizations for IgG4-Related Disease with a score of at least 20 points
  • You must have active signs and symptoms of IgG4-Related Disease that require starting glucocorticoid therapy (steroid medication to reduce inflammation) or increasing your current long-term steroid dose
  • If you are a woman who could become pregnant, you must not be pregnant or breastfeeding at the time of enrollment
  • If you are a woman who could become pregnant, you must agree to use effective birth control methods during the study and for at least 8 weeks after receiving the last dose of study medication
  • If you are a woman who could become pregnant, you must agree not to donate eggs during the study and for at least 8 weeks after the last dose of study medication
  • If you are a man, you must agree to use effective birth control methods or abstain from sexual intercourse during the study and for at least 8 weeks after the last dose of study medication, unless you have had surgery that makes you unable to father children
  • If you are a man, you must agree not to donate sperm during the study and for at least 8 weeks after the last dose of study medication
  • If you are a woman who could become pregnant, you must have a negative pregnancy test before starting the study and at specified times throughout the study
  • You must be able to understand and sign an informed consent form, which means you agree to participate and follow the study rules
  • You must be willing to follow all study procedures and attend all required study visits
  • You must have been treated with glucocorticoids for at least 3 weeks but no more than 6 weeks before joining the study, at a daily dose between 20 and 60 milligrams

Who cannot join the trial?

10 criteria

  • You have disease affecting only one organ where the main problem is scarring or thickening of tissue, such as scarring around the kidneys, a rare thyroid condition called Riedel's thyroiditis, scarring in the chest area, or scarring around the intestines
  • You have taken prednisone (a steroid medication used to reduce inflammation) at a dose higher than 60 mg per day within 4 weeks before starting the study or during the initial screening period
  • You have taken medications that suppress the immune system or treat rheumatological diseases (other than steroids) within 2 weeks before starting the study
  • You have participated in another research study and received an experimental treatment within 12 weeks before starting this study, or within a time period based on how long that treatment stays in your body
  • You have received a live vaccine (a type of vaccine containing weakened living organisms) or treatment with live infectious agents within 2 weeks before starting the study
  • You have active hepatitis B (a liver infection caused by a virus), active hepatitis C (another type of viral liver infection), or HIV (a virus that affects the immune system). You will be excluded if tests show current hepatitis B infection or certain antibodies indicating exposure to the virus
  • You have active tuberculosis (a bacterial infection usually affecting the lungs, also called TB) or are at high risk for tuberculosis, including if you have a history of tuberculosis that was not fully treated, a positive or unclear test result for tuberculosis, symptoms suggesting tuberculosis, or imaging scans showing possible tuberculosis
  • You have a history or current evidence of an unstable or uncontrolled medical condition affecting your heart, lungs, kidneys, liver, metabolism, blood, mental health, or an active infection that could put your safety at risk or interfere with the study
  • You have had cancer within the past 5 years, except for certain successfully treated cancers such as early cervical cancer, certain skin cancers, breast cancer with no return for at least 5 years, or prostate cancer with no return for at least 3 years
  • You meet other exclusion criteria specified in the detailed study protocol
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Investigated drugs

Obexelimab is an investigational medication being tested to treat IgG4-related disease, a condition where the immune system causes inflammation and damage to various organs in the body. This medication works by targeting specific immune cells that are thought to be involved in causing the disease. It is given as an injection under the skin once a week. The goal is to see if obexelimab can help prevent the disease from getting worse or coming back after patients have been treated with steroid medications.

What is already known about the treatment

Obexelimab - Obexelimab is an experimental medication given as an injection under the skin (subcutaneous injection) that is currently being studied in clinical trials and has not yet been approved for regular medical use. It is being tested as a treatment for IgG4-related disease, a rare condition where the immune system causes inflammation and damage to various organs in the body. Obexelimab works by targeting and blocking a specific protein called CD19 found on certain immune cells called B cells, which helps reduce the abnormal immune response that causes inflammation and organ damage in this disease. This medication belongs to a class of drugs called monoclonal antibodies, which are specially designed proteins that can attach to specific targets in the body to modify the immune system's behavior.

Investigated diseases

IgG4-Related Disease - IgG4-Related Disease is a rare immune system disorder characterized by abnormal growth of certain immune cells and the formation of masses or lesions in various organs throughout the body. The condition involves elevated levels of a specific type of antibody called immunoglobulin G4 (IgG4) in the blood. The disease typically causes swelling and inflammation in affected organs, which may include the pancreas, bile ducts, salivary glands, kidneys, lungs, and lymph nodes. The condition progresses through periods of active disease (flares) where new symptoms appear or previous symptoms return, alternating with periods of remission. During flares, patients may experience organ dysfunction, pain, and swelling in the affected areas. Without appropriate management, the inflammation can lead to scarring and permanent changes in the affected organs over time.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2022-500718-24-00Protocol codeZB012-03-001Estimated enrolment220 patientsSponsorZenas Biopharma (USA) LLC

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