Biogen Begins Global Phase 3 Study Of Felzartamab In Primary Membranous Nephropathy

Biogen Inc. has initiated patient dosing in PROMINENT, its global Phase 3 clinical trial evaluating felzartamab for the treatment of primary membranous nephropathy (PMN). The open-label study aims to enroll 180 adult patients with moderate-to-high-risk PMN to compare felzartamab with tacrolimus, a current standard therapy. The trial will run for 104 weeks and is expected to deliver primary results by 2029.

“We are encouraged by the opportunity to advance a Phase 3 study for primary membranous nephropathy, a condition that carries a significant risk of kidney failure. This is the third Phase 3 trial of felzartamab launched by Biogen this year, underscoring our ongoing commitment to developing potential novel treatment options for patients living with kidney disease,” said Travis Murdoch, Head of the Biogen West Coast Hub. 

Felzartamab is an investigational anti-CD38 monoclonal antibody designed to target CD38+ plasma cells, which produce disease-driving autoantibodies in immune-mediated conditions such as PMN. With no FDA-approved therapies for PMN, current treatments involve non-specific immunosuppressants and chemotherapies. Biogen’s trial will focus on both aPLA2R-positive and -negative patients, with complete remission of proteinuria at week 104 as the primary endpoint.

“Primary membranous nephropathy remains an unaddressed area of nephrology, for which there are no approved treatments. Felzartamab’s mechanism of action designed to deplete the cells that produce the pathogenic antibodies is exciting news for patients that are waiting for potential meaningful new treatment options. I’m grateful that Biogen is advancing research in this rare kidney disease and am eager to see the continued progress in the study’s enrollment,” said Mohamed El-Shahawy, M.D., MPH, MHA, Director of the Academic Research Institute in Los Angeles, Clinical Professor of Medicine at Keck-University of Southern California School of Medicine, and a principal investigator for the PROMINENT Phase 3 trial. 

The decision to advance felzartamab into Phase 3 was based on promising Phase 2 results from M-PLACE and NewPLACE studies, where felzartamab showed early and sustained reductions in disease-specific antibodies (aPLA2R) and improvements in proteinuria and serum albumin levels. The safety profile remained manageable, with mostly mild to moderate infusion-related reactions. PROMINENT is one of three Phase 3 studies Biogen is now running with felzartamab; the other two are targeting IgA nephropathy and late antibody-mediated rejection in kidney transplant recipients.