AIMS/HYPOTHESIS: In the Study Of diabetic Nephropathy with AtRasentan (SONAR), the endothelin receptor antagonist (ERA) atrasentan slowed progression of chronic kidney disease (CKD) in individuals with type 2 diabetes. Pre-clinical research suggests sex-based differences in the endothelin system might influence the efficacy and safety of atrasentan. We therefore assessed the effects of atrasentan in men and women participating in SONAR. METHODS: SONAR was a double-blind, placebo-controlled trial that compared atrasentan 0.75 mg/day with placebo in individuals with type 2 diabetes and CKD (eGFR 25-75 ml/min per 1.73 m RESULTS: Among 3668 randomised participants, 946 (25.8%) were female. Atrasentan significantly reduced the risk of the composite kidney outcome in female participants (HR 0.46 [95% CI 0.28, 0.76]) but not in male participants (HR 0.83 [95% CI 0.65, 1.05]
p value for interaction 0.032). Atrasentan compared with placebo reduced eGFR decline to a greater extent in female than in male participants (treatment effect difference between male vs female participants -0.99 ml/min per 1.73 m CONCLUSIONS/INTERPRETATION: Atrasentan showed greater kidney protection in female than in male participants but also induced more heart failure events in the female participants. These data suggest that sex-specific dosing regimens may be considered to optimise ERA treatment. TRIAL REGISTRATION: ClinicalTrials.gov NCT01858532.