Comparing CKD populations with T1D and T2D: a perspective based on the FINE-ONE and FIDELITY populations

Abstract Chronic kidney disease (CKD) is a common comorbidity of both type 1 diabetes (T1D) and type 2 diabetes (T2D) and is associated with increased mortality, end-stage kidney disease, and cardiovascular disease risk. Despite standard-of-care treatment with renin–angiotensin system inhibitors added to blood pressure and glycaemic control, people with CKD and T1D have a residual risk of CKD progression. Advances in therapeutic management have been limited over the past three decades, especially compared with CKD in T2D, for which new treatment options have emerged in the last 5 years. In this review article, we discuss similarities and differences between T1D and T2D populations with CKD, including epidemiology, pathophysiology, and clinical findings. Additionally, we explore the use of albuminuria as a potential bridging biomarker to extrapolate clinical evidence from one population to the other. This concept could offer a promising strategy to narrow the gap in treatment availability between these populations and address the unmet therapeutic need in people with CKD and T1D. The FINE-ONE trial is investigating the non-steroidal mineralocorticoid receptor antagonist finerenone in a population with CKD and T1D using change in urine albumin-to-creatinine ratio from baseline (ratio to baseline) over 6 months as its primary endpoint and bridging biomarker. Similarities between the populations from FINE-ONE and FIDELITY (a pooled dataset of individuals with CKD and T2D included in two large phase 3 clinical trials of finerenone) may inform the translation of clinical evidence on finerenone from people with CKD and T2D to those with CKD and T1D.