A Study Evaluating the Efficacy and Safety of Crovalimab Versus Eculizumab in Participants With Paroxysmal Nocturnal Hemoglobinuria (PNH) Not Previously Treated With Complement Inhibitors

This study is looking for adults and children aged 2 or older who have been diagnosed with PNH. To take part, your blood tests must show signs that red blood cells are actively breaking down (measured by high levels of an enzyme called LDH). You must also have had a vaccination against meningococcal bacteria (a common cause of meningitis) or be willing to receive one before starting the study.

You cannot take part if you have ever been treated with a complement inhibitor medicine before, or if you have had a bone marrow or stem cell transplant. People with certain serious bone marrow disorders, or those who have had a meningitis infection within the last six months, are also not eligible.

Because the effects of these medicines on unborn babies are not fully known, you cannot take part if you are pregnant or breastfeeding. Women who can become pregnant must agree to use reliable contraception during the trial and for several months after their final dose.

If you join the study, you will be placed into a group to receive either crovalimab or eculizumab. You will visit the clinic regularly so the medical team can give you your medication, check your overall health, and run routine blood and urine tests. These checks help the team see how well the medicine is protecting your red blood cells and look out for any side effects. The study lasts for several months, and the research team will explain the exact schedule of visits and follow-up checks before you decide to take part.