The rationale, design and baseline data of FLOW, a kidney outcomes trial with once-weekly semaglutide in people with type 2 diabetes and chronic kidney disease

Background Chronic kidney disease (CKD) is a common complication of type 2 diabetes (T2D). Glucagon-like peptide-1 receptor agonists (GLP-1RAs) improve glycaemic control and lower body weight in people with T2D, and some reduce the risk of cardiovascular (CV) events in those with high CV risk. GLP-1RAs might also have kidney-protective effects. We report the design and baseline data for FLOW (NCT03819153), a trial investigating the effects of semaglutide, a once-weekly (OW) GLP-1RA, on kidney outcomes in participants with CKD and T2D. Methods FLOW is a randomised, double-blind, parallel-group, multinational, phase 3b trial. Participants with T2D, estimated glomerular filtration rate (eGFR) >= 50-<= 75 ml/min/1.73 m(2) and urine albumin:creatinine ratio (UACR) >300-100-<5000 mg/g were randomised 1:1 to OW semaglutide 1.0 mg or matched placebo, with renin-angiotensin-aldosterone system blockade (unless not tolerated/contraindicated). The composite primary endpoint is time to first kidney failure (persistent eGFR <15 ml/min/1.73 m(2) or initiation of chronic kidney replacement therapy), persistent >= 50% reduction in eGFR or death from kidney or CV causes. Results Enrolled participants (N = 3534) had a baseline mean age of 66.6 years [standard deviation (SD) 9.0], haemoglobin A(1c) of 7.8% (SD 1.3), diabetes duration of 17.4 years (SD 9.3), eGFR of 47.0 ml/min/1.73 m(2) (SD 15.2) and median UACR of 568 mg/g (range 2-11 852). According to Kidney Disease: Improving Global Outcomes guidelines categorisation, 68.2% were at very high risk for CKD progression. Conclusion FLOW will evaluate the effect of semaglutide on kidney outcomes in participants with CKD and T2D, and is expected to be completed in late 2024.