Overview
C3 glomerulopathy (C3G) is a rare kidney disease caused by problems with a part of the immune system called the complement system. The complement system normally helps the body fight infections, but in C3G, it becomes overactive and deposits a protein called C3 in the tiny filters of the kidneys (called glomeruli). This damages the kidneys over time and can lead to serious kidney problems. C3 glomerulopathy includes two main subtypes: dense deposit disease (DDD) and C3 glomerulonephritis (C3GN). Both share the same underlying problem of uncontrolled complement activation but look slightly different under the microscope. Common symptoms include blood in the urine (which may look pink or brown), foamy urine from excess protein, swelling in the legs and around the eyes, high blood pressure, and fatigue. Over time, kidney function can decline. There is currently no cure for C3G. Treatment focuses on protecting the kidneys and slowing disease progression. Doctors may prescribe blood pressure medications called ACE inhibitors or ARBs to reduce protein in the urine, immunosuppressive drugs to calm the immune system, and in some cases newer complement-targeting therapies. Some patients eventually need dialysis or a kidney transplant, though the disease can unfortunately come back in a transplanted kidney. Research into complement-targeted treatments is active and offers hope for better options in the future.
Also known as:
Key symptoms:
Blood in the urine (pink, red, or brown urine)Foamy or bubbly urine from excess proteinSwelling in the legs, ankles, or feetPuffiness around the eyes, especially in the morningHigh blood pressureFatigue and tirednessDecreased urine outputUnexplained weight gain from fluid retentionLoss of appetiteNauseaHeadaches from high blood pressureGradual decline in kidney function
Clinical phenotype terms (23)— hover any for plain English
Variable
Can be inherited in different ways depending on the underlying gene
Variable
Can begin at different ages, from infancy through adulthood
FDA & Trial Timeline
10 eventsNovartis Pharmaceuticals
NovelMed Therapeutics — PHASE1, PHASE2
University Hospital, Strasbourg, France
eleva GmbH — PHASE1
FABHALTA: FDA approved
treatment of adults with complement 3 glomerulopathy (C3G), to reduce proteinuria
Kira Pharmacenticals (US), LLC. — PHASE2
Novartis Pharmaceuticals — PHASE3
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
2 availableEmpaveli
Treatment of adult and pediatric patients aged 12 years and older with C3 glomerulopathy (C3G) or primary immune-complex membranoproliferative glomerulonephritis (IC-MPGN), to reduce proteinuria. FDA …
Treatment of adult and pediatric patients aged 12 years and older with C3 glomerulopathy (C3G) or primary immune-complex membranoproliferative glomerulonephritis (IC-MPGN), to reduce proteinuria. FDA sNDA approval July 28, 2025. VALIANT Phase 3 trial (NCT05067127): 68% UPCR reduction vs placebo in 124 patients; 60% achieved >=50% UPCR reduction vs 5% placebo.
FABHALTA
treatment of adults with complement 3 glomerulopathy (C3G), to reduce proteinuria
Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Financial Resources
2 resourcesTravel Grants
No travel grants are currently matched to C3 glomerulopathy.
Community
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Start the conversation →Latest news about C3 glomerulopathy
Disease timeline:
New recruiting trial: Predictive Value of a Rectal Swab With Detection of Enterobacteria (ESBL-E), Carbapenemases, and High-level Cephalosporinase (HLC) on the Risk of Infections With C3G-resistant Enterobacteria
A new clinical trial is recruiting patients for C3 glomerulopathy
New recruiting trial: Phase 2 Study of ADX-038 in Complement-Mediated Kidney Disease
A new clinical trial is recruiting patients for C3 glomerulopathy
New recruiting trial: A Clinical Trial to Test the Safety, Tolerability, and How the Body Processes CPV-104 in Healthy People and Patients With C3-Glomerulopathy
A new clinical trial is recruiting patients for C3 glomerulopathy
New recruiting trial: Fabhalta Capsules Specified Drug-use Survey
A new clinical trial is recruiting patients for C3 glomerulopathy
New recruiting trial: Study of Efficacy and Safety of Iptacopan in Patients With C3 Glomerulopathy.
A new clinical trial is recruiting patients for C3 glomerulopathy
New recruiting trial: Home Reported Outcomes in C3G Study
A new clinical trial is recruiting patients for C3 glomerulopathy
Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.What subtype of C3 glomerulopathy do I have — dense deposit disease or C3 glomerulonephritis?,What is my current kidney function level, and how quickly is it changing?,Should I have genetic testing or testing for autoantibodies like C3 nephritic factor?,What treatment options are best for my specific situation, and are there clinical trials I could join?,What is my risk of eventually needing dialysis or a kidney transplant?,If I need a transplant in the future, what is the risk of the disease coming back in the new kidney?,Are there dietary changes or lifestyle modifications that can help protect my kidneys?
Common questions about C3 glomerulopathy
What is C3 glomerulopathy?
C3 glomerulopathy (C3G) is a rare kidney disease caused by problems with a part of the immune system called the complement system. The complement system normally helps the body fight infections, but in C3G, it becomes overactive and deposits a protein called C3 in the tiny filters of the kidneys (called glomeruli). This damages the kidneys over time and can lead to serious kidney problems. C3 glomerulopathy includes two main subtypes: dense deposit disease (DDD) and C3 glomerulonephritis (C3GN). Both share the same underlying problem of uncontrolled complement activation but look slightly dif
Are there clinical trials for C3 glomerulopathy?
Yes — 4 recruiting clinical trials are currently listed for C3 glomerulopathy on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.
Which specialists treat C3 glomerulopathy?
25 specialists and care centers treating C3 glomerulopathy are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.
What treatment and support options exist for C3 glomerulopathy?
2 patient support programs are currently tracked on UniteRare for C3 glomerulopathy. See the treatments and support programs sections for copay assistance, eligibility, and contact details.