The RENAL LIFECYCLE Trial: A RCT to Assess the Effect of Dapagliflozin on Renal and Cardiovascular Outcomes in Patients With Severe CKD

Objective:

To establish the reno- and cardioprotective efficacy and safety of dapagliflozin in patients with severe CKD

Study design:

Multicenter, randomized, controlled, double blinded, pragmatic, interventional trial

Study population:

• Patients with advanced CKD, i.e. an eGFR ≤25 mL/min*1.73m2

• Patients on dialysis (at least 3 months after start of dialysis)

• Patients with a kidney transplant and an eGFR ≤45 mL/min/1.73m2 (at least 6 months after transplantation)

Intervention:

Dapagliflozin 10 mg/day or matching placebo

Primary outcome measure:

Combined endpoint of all-cause mortality, kidney failure, and hospitalization for heart failure in the overall study population

Study duration:

18 month recruitment phase, 30 month follow-up after enrollment of the last patient: Total study duration intended to last 48 months. It should be noted that the trial is event driven and will be terminated when 468 primary composite outcomes have occurred. The exact trial duration may therefore be shorter or longer than the intended 48 months.

Study visits:

Screening, baseline, week 2, month 3, month 6 and every 6 months thereafter. Information needed for the trial will be obtained as much as possible from visits taking place as part of routine clinical care.

Sample size:

Renal Lifecycle is designed as an endpoint driven trial and will finish when 468 primary study outcomes have occurred. The investigators have estimated a sample size of 1750-2000 patients.

Novel aspects:

A unique patient population with severe chronic kidney disease at very high risk of adverse outcomes for whom very few proven effective therapies exist. The initiation and efficacy of SGLT2 inhibitors, including dapagliflozin, has not been studied before in this population. However, SGLT2 inhibitors have the potential to be very effective and well tolerated which would imply a major advance in the pharmacotherapy of these patients.

When patients reach a renal endpoint, e.g. start or chronic dialysis or receiving a kidney transplantation, study medication will not be stopped as customary in many other trials in nephrology, but continued in the new phase of their "renal lifecycle", hence the name of the trial.

Sub studies:

Cardiac MRI sub-study The cardiac MRI sub-study will evaluate the effect of dapagliflozin on cardiac remodelling, as compared to placebo, measured with indexed left ventricular mass (LVMi), an intermediate cardiovascular outcome, in 250 participants across all three groups of the Renal Lifecycle Trial (i.e. advanced CKD, dialysis, kidney transplant recipients). This will provide robust evidence on the mechanisms under-pinning the cardioprotective effects of SGLT2 inhibitors in this high-risk patient population.

Primary outcome: Difference in LVMi after 12 months dapagliflozin compared to placebo.

Secondary outcomes: Differences between intervention groups in the following parameters at 12 months post-randomization: non-indexed LVM; indexed left atrial volume; non-indexed left atrial volume; indexed left and right ventricular end diastolic volume; indexed left and right ventricular end systolic volume; left and right ejection fraction.

Echocardiography sub-study (STOP-HF-in-PD) The echocardiography sub-study (STOP-HF-in-PD) will evaluate the effect of dapagliflozin on cardiac function, as compared to placebo, measured by left ventricular global longitudinal strain (LV-GLS), in 100 participants with kidney failure treated with peritoneal dialysis (PD). This will provide additional evidence on the mechanisms underlying the cardiac effects of SGLT2i in patients with kidney failure. Furthermore, the LV-GLS-data will be related to measured CKD- and PD-associated mediators of heart failure (measured in serum, urine and peritoneal effluent). This will aid to determine their relevance in patients with kidney failure, as well as to define if and to what extent SGLT2i affect these mediators in patients with kidney failure.

Primary outcome: Difference in LV-GLS after 6 months dapagliflozin compared to placebo.

Secondary and exploratory objectives: Differences between dapagliflozin compared to placebo after 6 and 12 months post-randomization for: LV-GLS; E/e'-ratio; left atrial volume index; left atrial strain; tricuspid velocity; left ventricular ejection fraction; LVMi; Physical functioning (6 minute walking test and KCCQ-12); 24h urine volume; residual kidney function; average daily ultrafiltration volume; peritoneal glucose exposure; peritoneal membrane characteristics.

Combined Cardiac Imaging Sub-studies A subset of participants enrolled in the echocardiography sub-study will also participate in the cardiac MRI sub-study, allowing for a combined evaluation of both imaging modalities. The aim is to evaluate the use of echocardiography and cardiac MRI as a tool to identify patients at highest risk for heart failure and those who may benefit from SGLT2i-induced cardio-protection.

Secondary outcomes: Association between change in LV-GLS and change in LVMi from baseline to 12-months across intervention groups; association between change in LV-GLS at 6 months and change in LVMi at 12 months across intervention groups.

Cognitive sub-study Patients with chronic kidney disease (CKD) are at a much higher risk for developing cognitive impairment compared with the general population and both lower glomerular filtration rate and the presence of albuminuria are associated with its development. SGLT-2 inhibitor use is associated with better preservation of cognitive function in patients with CKD including those on hemodialysis and after kidney transplantation compared to placebo.Patients will be requested to perform the symbol digit modalities test at the same time as the questionnaires, i.e. at baseline (visit 2), visit 5 and visit 6, once every year after visit 6 and at EoT/EET.The primary outcome of the cognition sub study is the change over time in the number of correct answers in the symbol digit modalities test within 90 seconds.

Kidney metabolism substudy The primary aim of this substudy is to evaluate the effect of dapagliflozin 10 mg compared to a placebo on energy metabolism assessed by changes in the renal mitochondrial oxidative phosphorylation capacity in kidney transplant recipients participating in the RENAL LIFECYCLE Trial at the 3-month Follow-up Visit. Further aims of this substudy are to evaluate the differences in metabolic substrate preferences by measuring ketone body or acylcarnitine substrate-driven mitochondrial respiration following the randomization to dapagliflozin or placebo.

Differences in mitochondrial architecture including mitochondrial quantity and morphology will be assessed using electron microscopy.