The FDA has approved a new drug as the first and only treatment for adults with C3 glomerulopathy (C3G) to reduce protein in the urine. This approval marks a significant breakthrough, as previous treatment options focused solely on symptom management rather than addressing the underlying cause of the disease.
C3G is a rare kidney disease caused by an overactive immune system that leads to the buildup of a protein called C3 in the kidneys. This accumulation results in inflammation and potential kidney damage over time. Symptoms of C3G include protein or blood in the urine, swelling, and, in severe cases, kidney failure that may require dialysis or a transplant. The disease often affects young people, significantly impacting their health and daily life. While existing treatments help manage symptoms, there has been a critical need for medications that target the root cause of the condition.
The newly approved drug, known as iptacopan and sold under the brand name Fabhalta, works by blocking factor B in the immune system, reducing the buildup of C3 and preventing inflammation. This mechanism helps protect the kidneys from further damage and decreases proteinuria—excess protein in the urine. Fabhalta was first approved in December 2023 for treating certain immune-related diseases and is now approved specifically for C3G treatment.
A yearlong clinical trial evaluated the safety and effectiveness of twice-daily oral Fabhalta in adult patients with C3G. During the first six months of the trial, participants received either Fabhalta or a placebo along with supportive care. In the following six months, all participants received Fabhalta. The results demonstrated that the drug significantly reduced proteinuria within two weeks, with the benefits lasting throughout the year. Those who initially received the placebo and later switched to Fabhalta experienced similar improvements.
Fabhalta was generally well-tolerated, with no new safety concerns emerging during the study. Common side effects include headaches, sore throat, stuffy nose, nausea, diarrhea, stomach pain, rashes, and bacterial or viral infections. However, serious side effects may include increased cholesterol and triglyceride levels in the blood.
Due to its potential to increase the risk of serious infections, Fabhalta is available only through a specialized safety program called REMS (Risk Evaluation and Mitigation Strategy). Patients must receive specific vaccinations before starting treatment to protect against infections. These include vaccines for Streptococcus pneumoniae, which can cause pneumonia and other infections, and Neisseria meningitidis, which can cause meningitis. These vaccinations must be administered at least two weeks before the first dose of Fabhalta.
Before beginning treatment, patients should inform their healthcare provider of any liver conditions, ongoing infections, or fever. Additionally, patients who are pregnant or breastfeeding should consult their doctor, as the drug’s safety during pregnancy and lactation has not been fully established. Patients are advised not to breastfeed during treatment and for five days after the final dose.
Individuals taking Fabhalta should also inform their doctor about any prescription or over-the-counter medications, vitamins, or herbal supplements they are using, as these may interfere with the drug’s effectiveness or cause side effects. Patients should carry a Patient Safety Card throughout their treatment and for two weeks after their final dose. They must also promptly report any signs of a serious infection, such as fever with chills, headaches, rashes, chest pain and coughing, cold and clammy skin, confusion, or body aches.
This approval provides new hope for individuals suffering from C3G, offering a targeted treatment option that may significantly improve their quality of life and long-term kidney health.
