Complement 3 glomerulopathy (C3G) and primary immune-complex membranoproliferative glomerulonephritis (IC-MPGN) are rare kidney diseases that happen because of an overactive complement system (a part of your immune system that activates proteins to help your body heal from infections or injuries). In people with C3G or primary IC-MPGN, problems with the complement system cause clusters of proteins called immune complexes to form. These clusters get stuck in the kidneys and cause inflammation and damage to the filtering units in your kidneys called glomeruli.
Empaveli (pegcetacoplan) was approved by the FDA in July 2025 to lower protein levels in the urine (proteinuria) in adults and adolescents with C3G or primary IC-MPGN. It is the second approved medicine for people with C3G and the only approved medicine for people with primary IC-MPGN.
How Do I Use Empaveli?
Empaveli comes as an injection solution that contains 1,080 milligrams of Empaveli in 20 milliliters of liquid. One vial of the medicine contains a single dose. A 1,080-milligram dose is used twice weekly for adults. If you are younger than 18, your dose will be determined based on how much you weigh.
Before you use Empaveli for the first time, your health care provider will show you or a caregiver how to use it. After you learn how to use Empaveli, you or a caregiver may be able to give the dose at home. Empaveli is used in one of two ways.
- By a pump, obtained from your health care provider, that infuses the medicine under your skin over 30-60 minutes through a needle that you insert.
- By a one-time injector system that you stick to your stomach that infuses the medicine under your skin over 30-60 minutes.
How Was Empaveli Studied for Treating C3G and IC-MPGN?
A clinical study called VALIANT was done to see if Empaveli was safe and effective, compared to a placebo (containing no medicine), in 124 adults and adolescents with C3G or primary IC-MPGN. Most of the people in the study were female (57%) and White (73%), with an average age of 26. The study also included Asian people (15%), Black or African American people (1%), and 11% of participants classified their race as “other.” Of the people in the study, 77% had C3G, 22% had primary IC-MPGN, and 6% had C3G that came back after a kidney transplant. People in the study who were taking other medicines for their kidney disease had to be maintained on a steady dose for at least three months before the start of the study and throughout the treatment period.
Many people in the study were taking other medicines for their kidney disease.
- Almost all of the people in the study (91%) were taking angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs)
- About three-fourths of people were taking immunosuppressant medicines, such as mycophenolate mofetil or tacrolimus
- 40% were taking corticosteroids, such as prednisone
- 11% were taking sodium-glucose cotransporter 2 (SGLT2) inhibitors
People were randomly selected to be given either Empaveli or a placebo, both given as an infusion under the skin (subcutaneous) twice per week for 26 weeks. The placebo looked like Empaveli but did not contain any medicine. The dose that was given was based on each person’s weight. Neither the people in the study nor the doctors knew who received Empaveli and who got the placebo.
Everyone in the study was required to be vaccinated against Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae type B.
The main goal of the study was to see if Empaveli could lower the amount of protein in the urine after 26 weeks of treatment. The study also looked at changes in kidney function.
What Were the Main Benefits of Empaveli Seen in the Study?
People using Empaveli had greater decreases in the amount of protein in their urine, compared to those using the placebo. After six months, people using Empaveli had a 68% decrease in protein in their urine from the beginning of the study compared to those using the placebo. The effects seemed similar across all conditions and between adults and adolescents. In the first six months of treatment, people using Empaveli had less of a loss of kidney function than those using the placebo.
Your results may differ from what was seen in clinical studies.
What Should I Know About the Empaveli REMS Program?
Empaveli is only available through a restricted Risk Evaluation and Mitigation Strategy (REMS) program. The FDA requires REMS programs for some medicines that have serious safety concerns. These programs help to make sure that anyone prescribing, dispensing, or receiving the medicine is aware of the safety concern and that any measures needed to help the medicine be used safely are in place. In order to prescribe Empaveli, your health care provider will need to enroll in the REMS program. The REMS program requires your health care provider to tell you more about the serious risk of infections associated with Empaveli. They will also make sure that you have received all of the correct vaccines to minimize this risk. If you have not yet gotten the correct vaccines, they will make sure that you receive appropriate antibiotics, if needed.
Pharmacies that dispense Empaveli are also required to be certified through the Empaveli REMS program. They must also make sure that your doctor who prescribed Empaveli is certified through REMS. Your health care provider should give you information about which pharmacies you can use to get Empaveli.
As the person using Empaveli, you must learn more about the risk of serious infections associated with Empaveli from your health care provider. This discussion will include information about the need for certain vaccines, when antibiotics may be needed, and signs to look out for that may indicate a serious infection. When the drug is prescribed, you will be supplied with a Patient Safety Card that you should carry with you at all times during treatment and for two months after stopping treatment. This will help to let other people know that you are using Empaveli. It is important to carry the card with you even after you stop using Empaveli because your risk of getting a serious infection will last for several weeks after stopping it.
What Are the Possible Side Effects of Empaveli, and How Can I Prevent or Manage Them?
Fever, cough, and cold- or flu-like symptoms can commonly occur in people using Empaveli for C3G or primary IC-MPGN. There is also a risk of more serious infections due to specific bacteria, including Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type B. These infections can be life-threatening if not treated quickly. To prevent these infections, reduce your exposure to germs by washing your hands and avoiding people who are sick. You must also have up-to-date vaccines, including pneumococcal and meningitis vaccines, at least two weeks before starting treatment. If you have not been vaccinated and must start Empaveli, you will receive the vaccines and start antibiotics. Your health care provider will find out the right vaccines and timing for treatment.
Call your health care provider right away if you have the following symptoms of infection.
- Fever with or without chills, chest pain, and coughing, a fast heart rate, a rash, or a hard time breathing
- Body aches with flu-like symptoms
- Clammy skin
- A persistent headache with fever, nausea, and vomiting, or a stiff neck or back
- Tiredness
- Confusion
- Vision changes
Empaveli can also cause infusion or injection site reactions such as pain, redness, swelling, or bruising around the area where you get your dose. To limit these reactions, infuse or inject the drug into a different area of the body each time you get a dose, which is called “rotating” the injection site. Do not inject or infuse Empaveli into an area that is tender, bruised, red, or hard, and avoid infusing or injecting into tattoos, scars, or stretch marks.
If you have nausea while using Empaveli, try sipping clear liquids like water, ginger ale, or apple juice to stay hydrated. Eating bland foods, such as toast, crackers, or clear broth, can help. Get lots of rest and avoid strong smells or other triggers.
These are not all the possible side effects of Empaveli. Contact your health care provider for medical advice about side effects if you are having symptoms that bother you. You can report side effects to the FDA at 800-FDA-1088 (800-332-1088) or www.fda.gov/medwatch.
Is There Any Cost Assistance Available?
If you need support paying for Empaveli, the drugmaker may be able to help you. Check out their ApellisAssist program at empaveli.com/apellisassist-program to learn more about their patient assistance program or to ask questions about insurance coverage and out-of-pocket costs. You can also contact the drugmaker at 866-692-7527.