For decades, people with immune-complex membranoproliferative glomerulonephritis (IC-MPGN) had few treatment options. Most relied on broad immune-suppressing drugs that could slow kidney damage, but those didn’t address the underlying cause of the disease. Now, that’s starting to change. A new wave of research has opened the door to more targeted treatments — and fresh hope for patients.
New Pharmaceutical Treatments: Targeted Therapies
In July 2025, the FDA approved a new drug for IC-MPGN called pegcetacoplan. The disease affects the complement system, the part of the immune system that acts as your body’s first line of defense by activating proteins that help fight germs and bacteria. In people with IC-MPGM, the system goes into overdrive and damages the tiny filtering units inside of your kidneys called glomeruli. Pegcetacoplan works by blocking C3, a key protein in this process, which calms your immune response and helps protect your kidneys.
Andrew Bomback, MD, a nephrologist and assistant professor of medicine at Columbia University Irving Medical Center, says that the biggest difference between pegcetacoplan and existing therapies, like immunosuppressants, is that the drug is a targeted treatment. “This truly tilts the balance towards this being a precision medicine approach where we can say, OK, we're going to give a therapy that directly goes after what we think is causing the disease.”
In phase 3 clinical trials with people who had IC-MPGN or C3 glomerulopathy (C3G) — another rare disease that affects the kidney’s filtering units — those taking pegcetacoplan saw a 68% drop in the amount of protein in their urine compared to those who took a placebo. Since high amounts of protein in urine are usually a sign of kidney damage, the drop is a sign that the drug is working. This benefit continued for a full year after treatment, and patients taking the drug also showed stable kidney function.
Beyond pegcetacoplan, another targeted drug, iptacopan, is also showing promise for those with IC-MPGN. It works in a similar way, but instead of blocking the C3 protein, it targets a different part of the complement system called the factor B. By blocking factor B, iptacopan slows down the harmful immune response without shutting down the rest of the immune system.
The drug is already approved in the U.S. and Europe for other immune-related conditions, and in 2025, both the FDA and European Medicines Agency approved it for adults with C3G. That has many researchers feeling hopeful that it will work for IC-MPGN, too.
So far, clinical trials show promising results. In a phase 2 study, people with C3G who took iptacopan for 12 weeks had lower levels of protein in their urine and their kidney function either improved or stabilized. Phase 3 trials showed similar success. Iptacopan is now entering phase 3 clinical trials for IC-MPGN.
Nattawat Klomjit, MD, assistant professor in the University of Minnesota's Division of Nephrology and Hypertension, who is helping recruit for a phase 3 trial of iptacopan for IC-MPGN, says having more treatment options is a big step forward — not just medically, but also for patients, who may soon feel like they have more autonomy over their treatment.
Pegcetacoplan is given as an injection, whereas iptacopan is an oral medication. “There are some patients that say, ‘I have a needle phobia, I’d rather take a pill,’ whereas other patients might rather have an injection twice a week and be done with it,” he says.
Joining a Clinical Trial
For people interested in trying emerging treatments, joining a clinical trial gives you the opportunity to explore new treatment options while also helping advance research that may benefit others with IC-MPGN. Abdallah Geara, MD, associate professor of clinical medicine and director of the glomerular disease program at the University of Pennsylvania, says he often encourages patients to sign up for a clinical trial — especially if their disease is progressing.
By the time a drug reaches the later stages of clinical testing, most potential side effects have already been detected. These trials also have several systems in place to make sure the patient’s safety comes first.
One major advantage is early access to a promising new therapy. However, it’s important to remember that in a randomized double-blind study, some participants will receive a placebo instead of the actual treatment. The main downside is the possibility of side effects, but Geara adds that these are usually well understood by that point.
“We're hoping that these therapies will switch patients from a progressive chronic kidney disease to chronic, stable chronic kidney disease,” says Geara. “We know that there are a lot of inflammatory diseases of the kidney where, when we get to the root cause of the disease and address it appropriately, these patients can have a very long stable disease where they stop progressing towards end stages and dialysis.”
Because IC-MPGN is so rare — affecting only 1 or 2 people per 1 million — it can be hard for those living outside major urban centres to access clinical trials. But Geara is optimistic that this could soon change. He says that within the field of glomerular disease, there’s a movement to establish regional “Centers of Excellence,” where patients can find specialized care, expert advice, and clinical trial opportunities. Patient advocacy and physician groups are now formalizing a process to officially recognize these centers and create the infrastructure needed to support them.
Managing Your Mental and Physical Health at Home
As research moves forward, there are also steps you can take to care for yourself and help manage your condition at home. Klomjiut suggests working to control your blood pressure, limiting how much protein you eat, and taking precautions to avoid getting sick since IC-MPGN affects the immune system and your symptoms can get worse when you’re ill. This might include lowering stress, getting enough sleep each night, and trying to eat more nutritious foods.
Klomjit also acknowledges that being diagnosed with a chronic condition carries emotional weight. But he reminds patients that they’re not alone and encourages them to talk to their doctor about ways to find extra support or to join a Facebook group to connect with others living with the condition.
“There's a lot of emotion involved, especially if you were previously healthy and now suddenly have to take medication every day and can’t do things you used to do,“ he says. “But there are ways to modify activities so that you can still do certain things. It’s always hard in those first six months to a year, but as things stabilize and you start to adjust, most people are able to get back some quality of life.”