A Study to Evaluate the Efficacy and Safety of Frexalimab, Brivekimig, or Rilzabrutinib in Participants Aged 16 to 75 Years With Primary Focal Segmental Glomerulosclerosis or Minimal Change Disease

To join this study, doctors would need to confirm you have either primary Focal Segmental Glomerulosclerosis (FSGS) or primary Minimal Change Disease (MCD) based on a kidney biopsy. You would also need to be between 16 and 75 years old.

Researchers will check how much protein is in your urine and how well your kidneys are working (your eGFR). You should also have shown a good response to previous treatments like steroids, meaning your protein levels in your urine went down by more than 40%. If you are already taking certain medications for your kidneys, like steroids, RAAS inhibitors, or SGLT2 inhibitors, their doses need to have been stable for a set period before you join the study. Your weight must be between 45 and 120 kg.

You would not be able to join if your FSGS or MCD is caused by other medical conditions or genetics (though people with certain genetic risk factors called APOL1 are still eligible). Also, if your FSGS is a specific severe type called 'collapsing variant', or if you have kidney failure requiring dialysis or a transplant, you wouldn't be able to take part.

If you decide to take part, the study will last for up to 76 weeks in total – that's about a year and a half. For 24 of those weeks, you will be taking one of the study medicines or a placebo. During this time, you will have up to 18 visits to the clinic. These visits are important for the doctors to check on your health, see how the medicine is affecting you, and perform tests like blood and urine samples and blood pressure checks. This routine monitoring helps ensure your safety and allows researchers to collect all the necessary information about the potential effects of the treatments.