Biogen registers Phase 2 felzartamab trial in IgA nephropathy

Biogen's clinicaltrials.gov activity spans three separate registrations and updates posted between October 2 and October 22, 2026.

• Biogen has registered a Phase 2 open-label study of felzartamab in IgA nephropathy (NCT07889362, sponsor study ID 299GN201-IgAN), first posted October 22, 2026. The primary objective is to evaluate the effects of felzartamab on immunoglobulin A deposition in the kidney by immunofluorescence.¹ The study is listed as not yet recruiting, with enrollment estimated at 25 participants¹ and an estimated start date of November 16, 2026.
• Biogen's ALS trial of BIIB147, known as HORIZON (NCT07855211), was first posted October 2, 2026 and last updated October 19, 2026. The study is a randomized, double-blind, placebo-controlled multiple ascending dose study with an open-label extension evaluating safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy of BIIB147 administered intrathecally to adult participants with ALS.² The study remains listed as recruiting, with enrollment estimated at 69 participants across Phase 1 and Phase 2.²
• Biogen's observational study of Friedreich's Ataxia in the Gulf Cooperation Council region (NCT07887828, sponsor study ID SA-FRA-12346) was first posted October 21, 2026. The primary objective is to describe the natural history and participant experience of disease for participants with Friedreich's Ataxia in a real-world setting, with secondary objectives to estimate FRDA frequency in GCC countries and further characterize the participant population.³ The study is listed as not yet recruiting, with enrollment estimated at 40 participants³.