Biogen announced positive complete results from its Phase 2 IGNAZ study evaluating felzartamab, an investigational anti-CD38 monoclonal antibody, in patients with IgA nephropathy (IgAN). The data, presented at Kidney Week 2024, demonstrated substantial reductions in proteinuria, stabilization of kidney function, and a sustained treatment effect more than 18 months after the last dose of the drug.
The Phase 2 IGNAZ study (n=54) assessed the efficacy and safety of felzartamab in IgAN patients at high risk of progressive kidney dysfunction. Patients received a nine-dose regimen of felzartamab over six months. Results showed a mean reduction of approximately 50% in the urinary protein:creatinine ratio (UPCR) through month 24, indicating a prolonged impact on proteinuria.
Impact on Kidney Function
Kidney function, measured by estimated glomerular filtration rate (eGFR), was stabilized through 24 months in patients treated with felzartamab. This suggests the potential of felzartamab to preserve kidney function, a critical outcome in managing IgAN, which can lead to end-stage kidney disease in up to 40% of patients within 20 years of diagnosis.
Selective Reduction of IgA Antibody Levels
Further analysis revealed that felzartamab selectively and durably reduced IgA antibody levels, while IgG and IgM levels recovered to baseline within three months off-treatment. This selective reduction may allow for the maintenance of significant immune functions essential for infection protection.
Safety and Tolerability
Felzartamab was generally well-tolerated, with a safety profile consistent with prior studies. This is an important consideration for chronic treatments in kidney disease, where minimizing adverse effects is crucial.
Expert Commentary
"The complete results of the IGNAZ Study reaffirm our interim findings, showing a reduction in proteinuria, stabilization of kidney function, and sustained treatment effect more than 18 months after the last dose of felzartamab," said Jonathan Barratt, MD, PhD, FRCP, Mayer Professor of Renal Medicine at the University of Leicester. "This is promising news for patients and supports the potential of felzartamab to be a meaningful treatment option for people living with IgA nephropathy, a leading cause of chronic kidney disease."
Future Directions
Biogen is planning for Phase 3 development of felzartamab based on these promising Phase 2 results. The company believes that felzartamab, as a potential first-in-class therapeutic candidate, could address the significant unmet medical need in IgAN.
Uptal Patel, M.D., Head of Development, HI-Bio at Biogen, stated, "We are encouraged by the overall results of the IGNAZ study, especially given the significant unmet medical need for additional treatments to address high-risk IgA nephropathy."
