Biogen Highlights Scientific Progress in Rare Kidney Disease at ASN Kidney Week 2025

Biogen will present translational data at ASN Kidney Week 2025 suggesting a potential disease‑modifying signal for felzartamab in antibody‑driven kidney disease—findings that could alter when nephrologists consider targeted plasma cell therapy.

Current management of IgA nephropathy emphasizes supportive care and selective immunomodulation to reduce proteinuria and preserve eGFR. A differentiated biologic that selectively targets pathogenic plasma cells could shift both the timing and intensity of immunotherapy.

Phase 2 IGNAZ, summarized by the company, offers an early efficacy and safety snapshot for felzartamab-treated patients. The oral presentation pairs longitudinal gene‑expression profiling with reported preservation of humoral responses. Safety signals highlighted in the summary emphasize preserved vaccine immunity and no unexpected serious safety events in the cohorts presented. Taken together, the dataset supports a plausible disease‑modifying interpretation while remaining hypothesis‑generating pending full data release.

Company‑reported mechanistic data indicate that felzartamab depletes CD38+ plasma cells and plasmablasts, which could reduce pathogenic antibody production.

Clinical translation will require validated predictive markers and correlation with hard renal outcomes before routine adoption. Such biomarkers could inform adaptive trial designs and surrogate‑endpoint selection for future studies.

Patients with progressive IgA nephropathy and other antibody‑driven nephropathies—such as primary membranous nephropathy and antibody‑mediated rejection—are most likely to be affected. Algorithms may move toward earlier plasma cell–directed therapy and intensified monitoring of eGFR and proteinuria trajectories, but guideline change will depend on larger randomized trials with renal‑outcome endpoints and longer follow‑up. Near‑term milestones to monitor include ongoing Phase 3 programs and anticipated pivotal readouts around 2027.