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Study Comparing Crovalimab and Eculizumab for Patients with Paroxysmal Nocturnal Hemoglobinuria (PNH) Currently on Complement Inhibitors

Verified siteRegistered drugNo placebo
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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 rare blood disease called Paroxysmal Nocturnal Hemoglobinuria (PNH). PNH is a condition where red blood cells break down too early, leading to various health issues. The study is comparing two treatments: Crovalimab and Eculizumab. Both are medications that help manage PNH by inhibiting a part of the immune system known as the complement system, which is overactive in people with PNH.

The purpose of the study is to evaluate the safety and tolerability of Crovalimab compared to Eculizumab. Participants in the study will receive either Crovalimab or Eculizumab through injections or infusions. The study will monitor participants over a period to observe any side effects and how well the treatments work in managing the symptoms of PNH. Some participants may receive a placebo, which is a substance with no active medication, to help compare the effects of the actual treatments.

Throughout the study, participants will have regular check-ups to assess their health and the effectiveness of the treatment. This includes monitoring vital signs, blood tests, and any reactions to the medication. The study aims to provide valuable information on how these treatments can help people with PNH and improve their quality of life. The trial is expected to continue until 2030, allowing for comprehensive data collection and analysis.

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 assessment

    Upon joining the study, an initial assessment is conducted to confirm eligibility. This includes verifying a documented diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) and ensuring a body weight of at least 40 kg.

    A blood test is performed to check platelet count and lactate dehydrogenase (LDH) levels. Platelet count must be at least 30,000/mm³ without recent transfusion support, and LDH levels should be 1.5 times the upper limit of normal or lower.

  2. Step 2

    Randomization and treatment allocation

    Participants are randomly assigned to one of the study groups. Those in the randomized arms (Arm A and B) must be at least 18 years old and have completed a minimum of 24 weeks of treatment with eculizumab prior to the study.

    Participants in the non-randomized arm (Arm C) include those under 18 years old or those with specific treatment histories or conditions, such as treatment with ravulizumab or higher-than-approved doses of eculizumab.

  3. Step 3

    Treatment administration

    Participants receive either crovalimab or eculizumab. Crovalimab can be administered intravenously (IV) or subcutaneously (SC), while eculizumab is administered intravenously.

    The frequency and dosage of the medication depend on the specific treatment group and individual patient needs.

  4. Step 4

    Monitoring and follow-up

    Regular monitoring is conducted to assess the safety and effectiveness of the treatment. This includes tracking any adverse events, changes in vital signs, and laboratory test results.

    Participants are observed for any reactions at the injection site, infusion-related reactions, and signs of hypersensitivity or infection.

  5. Step 5

    Evaluation of treatment outcomes

    The study evaluates the concentration of crovalimab or eculizumab in the blood, the presence of anti-drug antibodies, and changes in biomarkers related to the disease.

    The effectiveness of the treatment is assessed by measuring changes in hemolysis parameters, LDH levels, and hemoglobin stabilization over a 25-week period.

  6. Step 6

    Completion of study participation

    At the end of the study period, participants complete questionnaires to assess treatment satisfaction and preference.

    The study is estimated to conclude by January 31, 2030, with ongoing assessments throughout the participation period.

Who can join the trial?

7 criteria

  • Must weigh at least 40 kg (about 88 pounds) at the start of the study.
  • Must have a confirmed diagnosis of Paroxysmal Nocturnal Hemoglobinuria (PNH), which is a rare blood condition, confirmed by a special test called high sensitivity flow cytometry of white blood cells (WBCs).
  • Must have a platelet count of at least 30,000 per cubic millimeter at the start of the study, without needing a blood transfusion within 7 days before the test. Platelets are small blood cells that help with clotting.
  • For patients in certain study groups (Arm A and B), must be 18 years or older and have been treated with a medication called eculizumab for at least 24 weeks before the study starts.
  • For patients in certain study groups (Arm A and B), must have a level of a substance called lactate dehydrogenase (LDH) that is no more than 1.5 times the upper limit of normal at the start of the study. LDH is an enzyme that can be measured in the blood.
  • For patients in another study group (Arm C), must be under 18 years old and currently treated with eculizumab, or currently treated with another medication called ravulizumab, or treated with higher-than-approved doses of eculizumab, or have a known C5 polymorphism with poorly controlled hemolysis by eculizumab or ravulizumab. Hemolysis is the breakdown of red blood cells.
  • Note: In France and the Czech Republic, patients under 18 years of age are not eligible to participate in the study.

Who cannot join the trial?

10 criteria

  • Patients with a history of severe allergic reactions to any of the study medications.
  • Patients who have received another investigational drug within the last 30 days.
  • Patients with active infections that require treatment with antibiotics.
  • Patients with a history of certain types of cancer.
  • Patients who are pregnant or breastfeeding.
  • Patients with a history of drug or alcohol abuse.
  • Patients with certain heart conditions.
  • Patients who have had a major surgery within the last 3 months.
  • Patients with uncontrolled high blood pressure.
  • Patients with severe liver or kidney disease.
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Investigated drugs

  • Crovalimab

    is a medication being studied for its potential to treat patients with a condition called paroxysmal nocturnal hemoglobinuria (PNH). This condition affects the blood, and crovalimab is designed to help by inhibiting certain proteins in the blood that can cause damage to red blood cells. The trial aims to see how safe and effective crovalimab is for patients who are already receiving treatment with other similar medications.

  • Eculizumab

    is another medication used in the treatment of paroxysmal nocturnal hemoglobinuria (PNH). It works by blocking specific proteins in the blood that can lead to the destruction of red blood cells. In this trial, eculizumab is used as a comparison to evaluate the safety and effectiveness of crovalimab. Patients in the trial are already being treated with eculizumab, and the study will compare the outcomes of those continuing with eculizumab to those switching to crovalimab.

What is already known about the treatment

  • Crovalimab

    Crovalimab is administered via intravenous infusion and is currently being studied in clinical trials for its safety and effectiveness in treating Paroxysmal Nocturnal Hemoglobinuria (PNH). It is a complement inhibitor, which means it works by blocking a part of the immune system known as the complement system, specifically targeting the C5 protein to prevent the destruction of red blood cells. This medication is classified as a monoclonal antibody and is being compared to eculizumab, another complement inhibitor, in ongoing research.

  • Eculizumab

    Eculizumab is given through intravenous infusion and is an established treatment for Paroxysmal Nocturnal Hemoglobinuria (PNH). It functions by inhibiting the complement system, particularly the C5 protein, to prevent the breakdown of red blood cells, thereby reducing symptoms and complications associated with PNH. As a monoclonal antibody, eculizumab is well-documented in medical literature and is being used as a control in studies comparing its efficacy and safety to newer treatments like crovalimab.

Investigated diseases

Paroxysmal Nocturnal Hemoglobinuria (PNH) – This is a rare blood disorder characterized by the destruction of red blood cells, leading to symptoms such as fatigue, shortness of breath, and dark-colored urine. The disease occurs due to a mutation in the PIGA gene, which affects the surface proteins that protect red blood cells from the immune system. Over time, the destruction of red blood cells can lead to anemia and other complications. Patients may experience episodes of hemolysis, where red blood cells break down more rapidly, often at night. The condition can also cause blood clots, which may lead to further health issues. PNH is a chronic condition that requires ongoing management to address its symptoms and complications.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-506526-37-00Protocol codeBO42161Estimated enrolment161 patientsSponsorF. Hoffmann-La Roche AG

sourced from the EU Clinical Trials Register and site verification

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