Positive interim results from the phase III trial of sibeprenlimab for the treatment of immunoglobulin A nephropathy in adults,- Otsuka

Otsuka Pharmaceutical Development & Commercialization, Inc. and Otsuka Pharmaceutical, Co. Ltd. (Otsuka), announce positive topline interim data from the ongoing Phase III clinical trial of sibeprenlimab for the treatment of immunoglobulin A nephropathy (IgA nephropathy) in adults.

Sibeprenlimab is an investigational, anti-APRIL monoclonal antibody (A PRoliferation-Inducing Ligand) that blocks a key initiating step in the immune pathogenic cascade of IgA nephropathy by limiting Gd-IgA1 production and immune complex formation. IgA nephropathy is a progressive, autoimmune, chronic kidney disease that can lead to end-stage kidney disease (ESKD) over the lifetime of most patients. Otsuka was previously granted Breakthrough Therapy designation for sibeprenlimab following favorable results of the Phase II ENVISION clinical trial.

The pre-specified interim analysis review, conducted by an independent data monitoring committee, found that the Phase III VISIONARY study (NCT05248646) met its primary endpoint by demonstrating that sibeprenlimab produced a statistically significant and clinically meaningful reduction in 24-hour uPCR (urine protein-to-creatine ratio) compared to placebo after nine months of treatment.  The study, a multicenter, randomized, double-blind, placebo-controlled trial consisting of approximately 530 adult patients (largest of its kind) with IgA nephropathy who were receiving standard-of-care therapy (defined as maximally tolerated ACE inhibitor or ARB +/- SGLT2 inhibitor), was designed to evaluate the efficacy and safety of sibeprenlimab 400 mg administered subcutaneously every four weeks, compared to placebo. The primary efficacy endpoint was to evaluate the change in 24-hour uPCR at 9 months compared with baseline.

“The positive interim data from this trial suggest that by targeting APRIL, we could provide a new therapeutic strategy for people living with this progressive kidney disease,” said John Kraus, M.D., Ph.D., executive vice president and chief medical officer, Otsuka Pharmaceutical Development & Commercialization, Inc. “We look forward to the completion of this study and reviewing the full results at a future timepoint. We are deeply appreciative to the patients with IgA nephropathy who participated in this trial, their caregivers, and investigators, all of whom continue to contribute greatly to this research.”

Brian Pereira, M.D., CEO of Visterra, Inc., an Otsuka U.S. affiliate, which designed and engineered sibeprenlimab, said, “We are encouraged by sibeprenlimab’s continuing progress and its potential to provide a needed and possibly disease-modifying treatment option to IgA nephropathy patients.”

The ongoing Phase III study continues in a blinded manner to evaluate the change in kidney function over 24 months as measured by estimated glomerular filtration rate (eGFR) and is expected to be completed in early 2026.  Further prespecified and exploratory analyses of the data will be conducted to determine the full potential of sibeprenlimab for the treatment of IgA nephropathy. Otsuka plans to review interim analysis results with the FDA to enable a potential regulatory submission for accelerated approval.