Complement Inhibitors

Complement inhibitors are a newer kind of medicine for IgA nephropathy. The complement system is part of your immune system that helps fight infection. In IgA nephropathy, this system can become overactive and add to the inflammation that damages your kidneys. Complement inhibitors block part of this system to help protect the kidneys and lower the protein in your urine.^1,2

How do they work?

Complement inhibitors quiet down a specific part of the immune system. By doing so, they reduce the inflammation in the kidney filters that drives IgA nephropathy, which helps lower the amount of protein leaking into your urine. Lowering urine protein is an important goal of treatment because it is linked with protecting your kidneys over time.^1,2

The FDA-approved complement inhibitor for IgA nephropathy

Iptacopan (Fabhalta®) is a complement factor B inhibitor that the US Food and Drug Administration (FDA) approved to reduce protein in the urine in adults with primary IgA nephropathy who are at risk of rapid disease progression. You take it by mouth. It has not been established whether Fabhalta® slows the decline of kidney function.^1,2

What are the possible side effects?

Side effects can vary from person to person. In studies of people with IgA nephropathy, the most common side effects of Fabhalta® included:²

• Upper respiratory tract infections (such as colds)
• Lipid (cholesterol and fat) changes in the blood
• Abdominal (belly) pain

Your doctor may check your cholesterol during treatment, since this medicine can raise lipid levels.²

These are not all the possible side effects of complement inhibitors. Talk to your doctor about what to expect when taking one. You also should call your doctor if you have any changes that concern you.

Other things to know

Fabhalta® has a boxed warning, the strictest warning from the US Food and Drug Administration (FDA). It has this warning because it can raise your risk of serious infections caused by certain bacteria (called encapsulated bacteria), which can become life-threatening quickly. Because of this risk:²

• You will need to be up to date on certain vaccines (including vaccines against meningococcal and other encapsulated-bacteria infections), usually at least 2 weeks before you start.
• Fabhalta® is available only through a restricted program called a REMS.
• Your care team will tell you the early signs of infection to watch for, and you should seek care right away if they appear.

Before beginning treatment for IgA nephropathy, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs.

Talk to your doctor

A complement inhibitor can be a powerful option, but it requires staying current on vaccines and watching for infection. Your doctor can explain whether one is right for you, what steps to take before you start, and what to watch for.^1,2