Iptacopan shows favorable efficacy and safety results in patients with C3 glomerulopathy: 12-month data from the phase 3 APPEAR-C3G study
Presenter: Carla M. Nester, MD, University of Iowa Stead Family Children's Hospital, Iowa City, Iowa.
Iptacopan-treated patients had significant and clinically meaningful proteinuria reduction at 6 months that was sustained for 12 months.
In patients with C3 glomerulopathy (C3G), iptacopan demonstrated a significant and clinically meaningful proteinuria reduction at 6 months on top of supportive care. The benefit was sustained for up to 12 months, according to data from the APPEAR-C3G study that was presented by Carla M. Nester, MD, University of Iowa Stead Family Children's Hospital, Iowa City, Iowa, in a Kidney Week 2024 oral presentation. In the study, iptacopan was well tolerated with a favorable safety profile.
C3G, a form of membranoproliferative glomerulonephritis, is an extremely rare, progressive kidney disease appearing most often in children and young adults. About 1 to 2 C3G cases per million population worldwide are diagnosed annually. C3G develops when C3 protein builds up in kidney glomeruli through overactivation of the alternative complement pathway, triggering inflammation and glomerular damage and leading to proteinuria, hematuria, and diminished kidney function. Within 10 years of diagnosis, about 50% of C3G patients progress to kidney failure, requiring dialysis or kidney transplantation. Furthermore, recurrence after transplant occurs in more than 55% of patients with C3G disease.
APPEAR-C3G (NCT04817618), a multicenter, randomized, double-blind, placebo-controlled, phase 3 study, included 74 adult patients with biopsy confirmed C3G. The patients were randomized 1:1 to either iptacopan 200 mg twice daily (n=38) or placebo (n=36). Groups were generally well-balanced, although the disease phenotype was more severe in the iptacopan arm, Dr. Nester noted. After all patients had completed 6 months of double-blind treatment, 43 (58.1%) patients in the iptacopan (n=22) and placebo (n=21) arms went on to 12 months with open-label treatment.
Dr. Nester stated that APPEAR met its primary endpoint of superior 24-hour proteinuria reduction (urine protein-to-creatinine ratio [UPCR]) sustained to month 12. The reduction in the 24-hour UPCR with iptacopan treatment reported at 6 months versus placebo was a statistically significant 35.1% (1-sided P = .0014, 95% CI, 13.8%-51.1%) and was sustained for 12 months. Also, iptacopan showed a sustained improvement in patients meeting the composite renal endpoint (≥ 50% reduction in UPCR plus ≤ 15% reduction in estimated glomerular filtration [eGFR] rate) at 12 months of 43.5% for the iptacopan versus placebo arm and 25.0% for those switched to iptacopan. Further, iptacopan led to improvements in the trajectory of eGFR compared with patients’ historical eGFR decline.
Dr. Nester observed further that iptacopan demonstrated a favorable safety profile consistent with prior reporting.
Funding
- Commercial Support from Novartis Pharma AG