Core Insights - Biogen has initiated dosing in a global, late-stage study of felzartamab for treating adult patients with primary membranous nephropathy (PMN), with top-line data expected in 2029 [1][4] - Felzartamab is an anti-CD38 antibody with a unique mechanism of action, and currently, there are no approved therapies for PMN, which typically relies on immunosuppressants or chemotherapy [1][6] - The PROMINENT study will evaluate the efficacy and safety of felzartamab compared to tacrolimus in moderate-to-high-risk PMN patients [3][5] Company Developments - Felzartamab was added to Biogen's pipeline through the acquisition of Human Immunology Biosciences last year, originally developed by MorphoSys AG [2] - The PROMINENT study will enroll approximately 180 PMN patients, with the primary endpoint being the percentage of patients achieving complete remissions at week 104 [5] - Biogen has also initiated dosing patients with felzartamab in two other phase III studies for late antibody-mediated rejection in kidney transplant recipients and IgA nephropathy [7] Clinical Study Details - The PROMINENT study will compare felzartamab to tacrolimus in 180 moderate-to-high-risk PMN patients, including newly diagnosed and relapsed cases [4][5] - Secondary endpoints will evaluate the effect of felzartamab on serum aPLA2R antibodies and patient-reported outcomes [5] - Previous phase II studies showed that felzartamab led to significant reductions in aPLA2R antibody levels and improvements in kidney markers [10] Market Context - PMN affects about 36,000 people in the United States and represents a serious unmet medical need, as current treatment options fail in about one-third of patients [6] - Year to date, Biogen's shares have declined by 17.9%, compared to the industry's decline of 3.6% [3]