EMPAVELI reduces proteinuria and stabilises kidney function in adolescents with C3G or primary IC MPGN

Biogen has reported published Phase III data showing that EMPAVELI, also known as pegcetacoplan, reduced proteinuria and helped preserve kidney function in adolescents with C3 glomerulopathy or primary immune complex membranoproliferative glomerulonephritis.

The findings come from a prespecified adolescent subgroup analysis of the Phase III VALIANT study and have been published in the Clinical Journal of the American Society of Nephrology.

The subgroup analysis included patients aged 12 to 17 years with C3 glomerulopathy, known as C3G, or primary immune complex membranoproliferative glomerulonephritis, also known as IC MPGN.

At week 26, adolescents treated with EMPAVELI achieved a 75% relative reduction in proteinuria compared with placebo.

The 95% confidence interval ranged from 59% to 84%, with a nominal p value below 0.001.

Reductions in proteinuria were observed as early as week four and continued through week 26.

Among adolescents receiving EMPAVELI, 71% achieved at least a 50% reduction in proteinuria, compared with 4% of those receiving placebo.

The nominal p value for this comparison was below 0.001.

A combined outcome assessing both kidney function and proteinuria also favoured EMPAVELI.

At week 26, 57% of treated adolescents achieved stable kidney function together with at least a 50% reduction in proteinuria, compared with 4% in the placebo group. The nominal p value was 0.002.

The adolescent cohort included 55 patients and represented nearly half of the overall VALIANT study population.

Biogen said this provides one of the largest randomised datasets involving adolescents with C3G or primary IC MPGN.

Bradley Dixon, MD, Section Chief of Pediatric Nephrology and Professor of Pediatrics at the University of Colorado School of Medicine and Children’s Hospital Colorado, said the diseases are often diagnosed early in life, making prevention of progressive kidney damage particularly important.

He said the VALIANT findings showed substantial reductions in proteinuria and stabilisation of kidney function in adolescents, consistent with results seen across the broader study population.

The subgroup analysis was first presented at the 2025 Annual Meeting of the European Society of Paediatric Nephrology.

The publication follows a recent U.S. Food and Drug Administration label expansion for EMPAVELI.

The updated indication makes EMPAVELI the first and only therapy approved to reduce both proteinuria and loss of kidney function in adults and adolescents aged 12 years and older with C3G or primary IC MPGN.

The FDA label change was supported by 52 week efficacy and safety findings from VALIANT.

Those data demonstrated sustained reductions in proteinuria alongside preservation of kidney function, measured using estimated glomerular filtration rate.

Daniel Jones, PhD, Vice President and Head of Global Medical Affairs for EMPAVELI at Biogen, said the published results add to evidence supporting use of the treatment in adolescents living with C3G and primary IC MPGN.

He said the data, together with the expanded U.S. indication, reinforce EMPAVELI’s potential to protect kidney health in these patients.

EMPAVELI was generally well tolerated in adolescents, and its safety profile was consistent with findings from the overall VALIANT study population.

---

---

Related Topics and Keywords

biogen, C3G, clinical trials, EMPAVELI, kidney disease, kidney function, nephrology, pegcetacoplan, pharma news, proteinuria, Valiant