Clinical trial designs of emerging therapies for diabetic kidney disease (DKD).

Current evidence for medical therapies for diabetic kidney disease (DKD) is largely based on large-scale clinical trials. These trials, however, often exhibit heterogeneity in participant characteristics and baseline kidney function. These differences may lead to misinterpretation in clinical practice, such that treatment effects from different trials are directly compared and generalized to broader populations beyond the population in which each trial was conducted. This is particularly relevant if comparisons on efficacy and safety are made when the underlying study populations are distinctly different. Indeed, key clinical trials evaluating sodium-glucose transport protein-2 inhibitors (SGLT2i), non-steroidal mineralocorticoid receptor antagonist (nsMRA), and glucagon-like peptide-1 receptor agonist (GLP-1RA) differed in recruitment requirements (inclusion/exclusion criteria), resulting in differences in the severity of the underlying kidney disease as well as risk factor profiles. Moreover, these trials defined their primary and secondary outcomes differently. Collectively, these factors lead to distinct study populations with different baseline risks for DKD progression in the placebo arm in each clinical trial. Consequently, a direct head-to-head comparison of the treatment effect between treatments using relative risk measures from placebo-controlled clinical trials alone is not recommended. In addition, healthcare professionals should be equipped to understand the specific target population of clinical trials to avoid over-generalization when drawing conclusions from these trials.