Biogen reports 75% proteinuria reduction with Empaveli

Biogen announced on 17 September 2026 that adolescent subgroup data from the Phase 3 VALIANT trial appeared in the Clinical Journal of the American Society of Nephrology. The study evaluated Empaveli in patients aged 12 to 17 years living with C3 glomerulopathy or primary immune complex membranoproliferative glomerulonephritis.

The prespecified subgroup analysis evaluated 55 adolescents out of 124 total patients aged 12 years and older enrolled in the trial. Researchers assigned 28 adolescent participants to the Empaveli treatment arm and 27 adolescent participants to the placebo group for a 26-week randomized period, followed by a 26-week open-label extension.

At Week 26, Empaveli demonstrated a 75% relative reduction in proteinuria compared with placebo. In the treatment arm, 71% of adolescent patients achieved at least a 50% drop in proteinuria, compared with 4% of participants on placebo.

The trial also tracked kidney stability alongside protein clearance. A composite endpoint of stable kidney function and proteinuria reduction was reached by 57% of adolescent patients receiving Empaveli, compared with 4% in the placebo group.