First patient enrolled in pivotal phase III BEYOND study of zigakibart for patients with IgA nephrology.- Chinook Therapeutics

The BEYOND study (see www.clinicaltrials.gov, identifier NCT05852938) is a global, randomized, multicenter, double-blind, placebo-controlled phase III clinical trial comparing the safety and efficacy of zigakibart versus placebo in patients with IgAN at risk of progressive loss of kidney function. Approximately 272 patients with biopsy-proven IgAN and eGFR greater than 30 mL/min/1.73m2 will be randomized to receive 600 mg of zigakibart or a matched placebo subcutaneously every two weeks for 104 weeks. An additional exploratory cohort, not included in the primary analysis, will be comprised of approximately 20 subjects (10 subjects per arm) with biopsy-confirmed IgAN and eGFR of greater than 20 to less than 30 mL/min/1.73 m2.

The primary efficacy endpoint of the BEYOND study is to evaluate the effect of zigakibart versus placebo on proteinuria as measured by change in urine protein to creatinine ratio (UPCR) from baseline to 40 weeks. Secondary and exploratory objectives include evaluating change in eGFR from baseline to week 104; composite clinical outcome of 30% or 40% reduction in eGFR, eGFR less than 15 mL/min/1.73m2 or dialysis, kidney transplantation or all-cause mortality; safety and tolerability; impact of zigakibart on disease biomarkers and health-related quality of life, as well as analysis of zigakibart pharmacokinetics and immunogenicity.