Biogen's EMPAVELI Shows 75% Proteinuria Reduction in Pediatric Kidney Disease Trial — Biogen Inc.

Event summary

Biogen's EMPAVELI achieved a 75% relative reduction in proteinuria in adolescents with C3G or primary IC-MPGN within 6 months vs. placebo.
71% of EMPAVELI-treated adolescents saw at least a 50% reduction in proteinuria, compared to 4% on placebo.
FDA recently expanded EMPAVELI’s label to include reducing kidney function loss in patients aged 12+.
Results published in the Clinical Journal of the American Society of Nephrology on September 17, 2026.

The big picture

Biogen’s positive Phase 3 data for EMPAVELI in pediatric patients reinforces its leadership in treating rare complement-mediated kidney diseases. The FDA’s recent label expansion and peer-reviewed publication validate the drug’s clinical utility, potentially broadening its adoption in a niche but high-unmet-need market. The results also highlight the growing focus on pediatric indications in rare disease therapeutics, where early intervention can significantly alter disease progression.

What we're watching

Market Expansion: Whether Biogen can leverage these results to expand EMPAVELI’s market share in pediatric nephrology.
Regulatory Dynamics: The pace at which other regulators follow the FDA’s label expansion for EMPAVELI.
Competitive Positioning: How this data positions EMPAVELI against emerging therapies for rare kidney diseases.