Biogen Reports Positive Phase 2 IGNAZ Study Results of Felzartamab in IgA Nephropathy at ASN Kidney Week 2024

On October 26, 2024, Biogen Inc. (Nasdaq: BIIB) revealed the full results from the Phase 2 IGNAZ study, which evaluated felzartamab in patients with IgA nephropathy (IgAN). The findings, presented at Kidney Week 2024 in San Diego, California, demonstrated significant reductions in proteinuria, stabilization of kidney function, and a sustained treatment effect lasting over 18 months after the final dose of felzartamab.

Felzartamab, an investigational anti-CD38 monoclonal antibody, has shown promise as a potential first-in-class therapeutic for various rare immune-mediated conditions. It is currently in planning for Phase 3 development. IgA Nephropathy, a leading cause of chronic kidney disease, sees up to 40% of patients progress to end-stage kidney disease roughly 20 years post-diagnosis.

The IGNAZ study included 54 participants and focused on the efficacy and safety of felzartamab for those with IgAN at high risk of progressive kidney dysfunction. Patients who received a nine-dose regimen of felzartamab over six months showed marked reductions in proteinuria levels, as measured by the urinary protein:creatinine ratio (UPCR), and stabilization of kidney function, assessed by estimated glomerular filtration rate (eGFR), over a 24-month period. Impressively, they maintained an average reduction of approximately 50% in the UPCR beyond 18 months after their last dose, indicating felzartamab's potential to preserve kidney function and be administered in treatment cycles instead of continuously.

Further analysis highlighted that felzartamab resulted in selective and durable reductions in IgA antibody levels. Meanwhile, IgG and IgM levels returned to baseline three months off-treatment, signifying that essential immune functions could be maintained, which is crucial for infection protection. The safety profile of felzartamab was generally well-tolerated and consistent with previous studies.

Jonathan Barratt, MD, PhD, FRCP, Mayer Professor of Renal Medicine at the University of Leicester, commented on the positive outcomes of the IGNAZ study, emphasizing the substantial reductions in proteinuria and stabilization of kidney function. He noted the promising implications for patients with IgA nephropathy, supporting felzartamab as a potential meaningful treatment option.

Uptal Patel, M.D., Head of Development at HI-Bio, expressed encouragement from the study results, especially considering the significant unmet medical need for treatments targetting high-risk IgA nephropathy. He extended gratitude to all participants, investigators, and study staff, emphasizing the importance of these findings in continuing to evaluate felzartamab's role in preserving kidney function as the company prepares for Phase 3.

Felzartamab is an investigational human monoclonal antibody targeting CD38, a protein found on mature plasma cells. It has potential as a first-in-class therapeutic candidate, with applications across various immune-mediated diseases. Clinical studies have shown that felzartamab selectively depletes CD38+ plasma cells, potentially improving clinical outcomes for a range of diseases driven by pathogenic antibodies. Originally developed by MorphoSys AG for multiple myeloma, felzartamab's rights for development and commercialization, excluding China, were licensed to Human Immunology Biosciences (HI-Bio). Biogen acquired HI-Bio in July 2024.

Though felzartamab has not yet received regulatory approval and its safety and effectiveness are not fully established, the investigational therapeutic candidate shows promise. IgA nephropathy remains the most common primary glomerulonephritis globally and is a leading cause of chronic kidney disease. It accounts for significant percentages of native-kidney biopsies in various regions, including 40% in Japan and 25% in Europe.

Biogen, founded in 1978, continues to be a leading biotechnology company focused on delivering innovative medicines. By understanding human biology, the company aims to develop treatments that provide superior outcomes and deliver long-term growth through bold, balanced investments.