Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Not recruitingRare disease

Study of Obexelimab for Patients with Warm Autoimmune Hemolytic Anemia

Verified siteInvestigational
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

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 called warm autoimmune hemolytic anemia (wAIHA). This is a disease where the body's immune system mistakenly attacks and destroys its own red blood cells, leading to anemia. The trial will test a treatment called Obexelimab, which is given as an injection under the skin. The study will also use a placebo, which looks like the treatment but does not contain the active medicine.

The purpose of the study is to evaluate the safety and effectiveness of Obexelimab in treating patients with wAIHA. The study is divided into three parts. In the first part, the safety and appropriate dose of Obexelimab will be confirmed. In the second part, the treatment will be compared to the placebo to see if it helps improve anemia. In the third part, patients will continue to receive Obexelimab to further assess its safety and benefits over a longer period.

Participants will receive weekly injections and will be monitored regularly to check their response to the treatment. The study aims to see if Obexelimab can help increase hemoglobin levels, which are important for carrying oxygen in the blood, and reduce the need for additional treatments like blood transfusions. The trial will also look at how well patients tolerate the treatment and any side effects they may experience.

The research process

The trial runs in 3 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Safety and dose confirmation run-in period

    During this initial phase, you will receive a weekly injection of obexelimab under the skin. This is known as a subcutaneous injection. The purpose is to evaluate the safety and tolerability of the medication.

    Your response to the treatment will be monitored closely to assess any clinical benefits related to your anemia condition.

  2. Step 2

    Randomized control period

    In this phase, you will continue to receive weekly subcutaneous injections. You may receive either obexelimab or a placebo, which is a solution without active medication.

    The goal is to further evaluate the clinical benefits of the treatment on your anemia. Your health and response to the treatment will be monitored regularly.

  3. Step 3

    Open-label extension period

    If you complete the previous phases, you may enter this period where you will receive weekly subcutaneous injections of obexelimab.

    This phase aims to continue evaluating the safety and effectiveness of the treatment, including its impact on the need for additional therapies.

Who can join the trial?

18 criteria

  • Must be a male or female who is at least 18 years old.
  • Must have been diagnosed with warm autoimmune hemolytic anemia (wAIHA) for at least 3 months and currently receiving or have previously received treatment for it.
  • Must have a positive DAT test, which checks for specific antibodies (anti-IgG or anti-IgA) related to wAIHA.
  • Must have tried at least one previous treatment for wAIHA, such as steroids or other specific medications.
  • If taking prednisone or prednisolone, the dose must not be more than 20 mg per day and should have been stable for at least 4 weeks.
  • If taking immunosuppressants (medications that lower the immune system's activity), the dose must have been stable for at least 12 weeks. Allowed medications include azathioprine, mycophenolate mofetil, cyclosporine, and cyclophosphamide.
  • Must have a hemoglobin (Hgb) level between 7 and less than 10 g/dL. Hemoglobin is a protein in red blood cells that carries oxygen.
  • Must show at least one sign or symptom of anemia, as determined by the study doctor.
  • Must have a platelet count of at least 50,000 mm3. Platelets are cells that help with blood clotting.
  • Must have a neutrophil count of at least 1,000 mm3. Neutrophils are a type of white blood cell important for fighting infections.
  • Must have serum albumin and serum calcium levels within the normal range. These are proteins and minerals in the blood.
  • Must have a total serum IgG level of at least 600 mg/dL. IgG is a type of antibody in the blood.
  • Must have a creatine kinase value less than 2 times the upper limit of normal (ULN). This is an enzyme that can indicate muscle damage.
  • If the spleen has been removed (splenectomy), it must have been at least 4 months ago, and the patient must be vaccinated according to local guidelines.
  • Patients with other autoimmune disorders may be eligible if their condition has been stable for at least 4 months and they are on stable treatment.
  • Females must not be pregnant or breastfeeding and must agree to use contraception if they are of childbearing potential.
  • Males must agree to use contraception or be surgically sterile and refrain from donating sperm during the study.
  • Must be able to provide informed consent, meaning they understand and agree to the study requirements.

Who cannot join the trial?

10 criteria

  • Patients who have any other serious health condition that might interfere with the study.
  • Patients who are pregnant or breastfeeding.
  • Patients who have had a recent infection that required treatment with antibiotics.
  • Patients who have received another investigational drug within a certain period before the study.
  • Patients who have a history of drug or alcohol abuse.
  • Patients who have a known allergy to the study medication or its ingredients.
  • Patients who have a history of certain types of cancer.
  • Patients who have a condition that affects their immune system.
  • Patients who have had a blood transfusion within a certain period before the study.
  • Patients who are unable to comply with the study procedures.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Not recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

Obexelimab is a medication being studied for its potential to help people with a condition called warm autoimmune hemolytic anemia (wAIHA). This condition causes the immune system to mistakenly attack and destroy red blood cells, leading to anemia. Obexelimab is given as an injection under the skin, and the study is looking at how safe it is and whether it can improve anemia symptoms in patients with wAIHA. The trial is also examining how well patients respond to the treatment over time and whether it can reduce the need for other rescue therapies. The goal is to see if obexelimab can provide a clinical benefit by improving the health of patients with this type of anemia.

What is already known about the treatment

Obexelimab – Obexelimab is administered through a weekly subcutaneous injection, which means it is given under the skin. It is currently being studied in a Phase 3 clinical trial for its effectiveness and safety in treating warm autoimmune hemolytic anemia (wAIHA), a condition where the immune system mistakenly attacks and destroys red blood cells. The medication works by targeting specific proteins involved in the immune response, helping to reduce the destruction of red blood cells. Obexelimab is classified as an immunomodulatory agent, which means it helps to regulate or normalize the immune system's activity.

Investigated diseases

Warm Autoimmune Hemolytic Anemia – This disease is characterized by the immune system mistakenly attacking and destroying the body's own red blood cells. It typically progresses with the gradual onset of symptoms such as fatigue, pallor, and shortness of breath due to the reduced number of red blood cells. As the condition advances, individuals may experience jaundice, which is a yellowing of the skin and eyes, due to the breakdown of red blood cells. The spleen may become enlarged as it works harder to remove the damaged cells from the bloodstream. Over time, the body may struggle to produce enough new red blood cells to replace those that are destroyed, leading to worsening anemia. The severity and progression of symptoms can vary widely among individuals.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2022-501005-12-00Protocol codeZB012-03-002Estimated enrolment27 patientsSponsorZenas Biopharma (USA) LLC

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.