This study aimed to investigate whether zetomipzomib, added to standard of care treatment in patients with active LN, was able to reduce disease activity over a treatment period of 52 weeks. The background standard of care therapy was mycophenolate mofetil (MMF) and initial optional treatment with IV methylprednisolone, followed by a tapering course of oral corticosteroids.
Patients were required to have a diagnosis of LN according to established diagnostic criteria and clinical and biopsy features suggestive of active nephritis.
Patients were randomized in a 2:1 ratio to receive either zetomipzomib (30 mg or 60 mg) or placebo administered as a subcutaneous injection once weekly for 52 weeks, followed by a 4-week safety follow-up period. Efficacy was to be assessed by measuring the level of proteinuria (as measured by urine protein to creatinine ratio \[UPCR\]) and estimated glomerular filtration rate (eGFR) as compared to current standard of care treatment. Safety was also assessed throughout the study to ensure an acceptable safety profile.