GFR and renal pathology in WT and AS mice treated with vehicle or sparsentan from 4 wk of age. (A) Comparison of GFR at 9 wk of age. ***P<0.001, ****P<0.0001, WT-V (n=6) or AS-SP (n=15) compared to AS-V mice (n=10). Preservation of GFR in AS-SP mice compared to AS-V mice was associated with amelioration at 10 wk of age of (B) GS and (C) TIF. **P<0.01 AS-SP (n=7) compared to AS-V (n=4). (D) Representative sections from three WT-V, AS-V, and AS-SP mice following staining with an anti-COLI antibody, indicating the attenuation of fibrosis in 10-wk-old AS-SP mice. Data in panel A are shown as their median; data in B and C are shown as their mean±SD. Analysis of panel A data used 1-way ANOVA followed by Tukey’s multiple comparison test. Analysis of panels B and C data was conducted using a 2-tailed Student’s t test. All analyses were performed using GraphPad Prism.