Breakthrough Therapy Offers Hope for Children with Rare, Life-Threatening Kidney Disease
A groundbreaking new treatment is offering a beacon of hope for children and young adults battling C3 glomerulopathy (C3G), a rare and often fatal kidney disease. Pioneering research and clinical expertise from University of Iowa Health Care Stead Family Children’s Hospital have been instrumental in the development and approval of pegcetacoplan, a first-of-its-kind therapy targeting the root cause of this devastating condition.
C3 glomerulopathy is an ultra-rare disease affecting approximately 5,000 Americans, leading to progressive kidney damage and, for over half of patients, end-stage kidney failure within a decade of diagnosis. Previous treatments focused on managing the inflammatory symptoms, but pegcetacoplan represents a paradigm shift by directly addressing the dysfunction within the body’s complement system – a critical component of the immune response.
Dr. Carla Nester, director of the Rare Renal Disease Clinic at UI Health Care, spearheaded the global pediatric clinical trial for pegcetacoplan. The results, published in the New England Journal of Medicine, were remarkably positive. Patients experienced a 68% reduction in protein levels in their urine, alongside stabilization of kidney function. Notably, up to 67% of children achieved complete remission, and 72% exhibited no disease activity on kidney biopsies.
“This is the closest thing to a cure we’ve ever seen for this disease,” stated Dr. Nester, a professor of pediatrics at UI Health Care Stead Family Children’s Hospital. “We still need to follow the long-term outcomes for these patients, but the data from this trial are absolutely amazing.”
The Phase III trial, a randomized, double-blind, placebo-controlled study, involved 124 patients across 122 centers in 19 countries. Based on these compelling results, the U.S. Food and Drug Administration (FDA) approved pegcetacoplan earlier this year for patients 12 years and older with C3G, as well as primary immune complex membranoproliferative glomerulonephritis (IC-MPGN), a closely related rare kidney disease.
This advancement builds upon decades of foundational research into the complement system, led by Dr. Richard Smith, a UI professor of pediatrics and otolaryngology. His work, combined with Dr. Nester’s clinical expertise, has positioned Iowa and the Stead Family Children’s Hospital as a leading center for C3G care in the United States, offering comprehensive diagnosis, advanced management, and opportunities for participation in cutting-edge research, including the VALIANT trial.
“It’s the combination of the research and the clinical unit that makes Iowa such a powerhouse,” Dr. Nester explained. The UI team has cultivated a strong rapport with patients and families, attracting individuals from across the globe seeking specialized care. “One of our patients used to fly in from Qatar to be seen in our clinic, and another moved from Europe to be under our care,” Dr. Nester shared. “That’s how well known and trusted our program has become.” This trust translated into UI Health Care being the highest-enrolling center in the global pegcetacoplan study, a critical factor in demonstrating the drug’s efficacy.
The research originating from Dr. Smith’s lab revealed that inhibiting excessive activation of the complement pathway held the key to effective treatment. UI researchers then collaborated with pharmaceutical companies to develop and test drugs capable of precisely blocking the malfunctioning component of the complement system – a significant improvement over previous treatments relying on broad anti-inflammatory drugs like steroids.
Pegcetacoplan is administered via twice-weekly injection, a method preferred by many young patients over daily oral medications. Furthermore, another complement-inhibiting drug, iptacopan, also received FDA approval earlier this year for the treatment of adult C3G patients, with UI Health Care again leading global enrollment in its clinical trial.
The impact of these new medicines is already being felt by patients. Dr. Nester recounted the story of a college student now thriving in his career after achieving full remission, and of pediatric patients who can now focus on enjoying normal childhoods without the constant worry of their health.
“This is the year we finally get to help patients,” Dr. Nester concluded. “It’s been a long road, but we’re here.”
More information: Trial of Pegcetacoplan in C3 Glomerulopathy and Immune-Complex MPGN, New England Journal of Medicine (2025). DOI: 10.1056/NEJMoa2501510.