Dr. Tae Won Yi, Ph.D.
Supervisor(s): Dr. David Cherney and Dr. Adeera Levin
Award: KRESCENT Post-Doctoral Fellowship
Institution: University Health Network
Year: 2026-2028
Project Title: The gfR Effects and DEcline in albuminuria with FINErenone in stage 4 CKD
Topic(s): Chronic Kidney Disease
Biography
Dr. Tae Won Yi is a nephrologist and postdoctoral fellow at the University of Toronto in the Cardiovascular, Renal, Endocrinology, and Metabolic Diseases Fellowship. He completed his internal medicine and nephrology training at the University of British Columbia in Vancouver, Canada, and earned a PhD at the University of New South Wales in Sydney, Australia. His Ph.D. focused on improving the uptake of evidence-based therapies in CKD and diabetes. His research interests include clinical trials and implementation science, with an emphasis on generating and translating evidence into routine clinical practice.
Lay Summary
Background: Chronic kidney disease (CKD) affects about 4 million Canadians, and more than 49,000 are living with kidney failure. Kidney failure happens when the kidneys can no longer clean the blood well enough to keep a person alive without dialysis or a kidney transplant. Kidney failure affects much more than just the kidneys, as people with kidney failure are at extremely high risk of heart disease and early death. They often feel unwell, have frequent hospital visits, and face major disruptions to daily life. This also places heavy pressure on families and the healthcare system. For these reasons, slowing down the progression of kidney disease is extremely important. Stage 4 CKD is the second-to-last stage before kidney failure. Many people at this stage also have protein leaking into their urine, which is a clear sign of kidney damage and a warning that the disease may continue to worsen. Studies have shown that reducing protein in the urine is linked to slower kidney function decline and fewer heart problems. People with stage 4 CKD are at a critical turning point where treatment could still meaningfully delay kidney failure. However, many important clinical trials have excluded them because they are more likely to develop high potassium levels in the blood. High potassium can be dangerous because it affects the heart’s rhythm. Over the past several years, a newer medication called finerenone has been shown to slow kidney damage and reduce heart problems in people with earlier stages of CKD. However, people with stage 4 CKD were not included in those studies because finerenone can increase potassium levels. As a result, we do not know whether this medication is safe or helpful for those who may need it most. People with stage 4 CKD face very high health risks and have very limited effective medications available. Recent advances now allow doctors to manage potassium levels more effectively. Newer potassium lowering medications are available and have been proven safe and effective. In addition, finerenone has been shown to have lower risk of causing high blood potassium levels than older medications in the same class. Together, these developments create an opportunity to study finerenone safely in people with advanced CKD and fill an important knowledge gap.
Purpose: The REDEFINE-CKD pilot study will test whether finerenone can safely reduce protein in the urine in people with stage 4 CKD. We will also test whether careful potassium monitoring can make this treatment safe for patients at higher risk of potassium problems and whether this approach is practical to use.
Method: We will enrol 154 adults at six academic health centres across Canada. Participants with stage 4 CKD and elevated protein in the urine who have safe potassium levels at the start of the study will be invited. Participants will be randomly assigned to receive either finerenone or a placebo (a look-alike pill with no active medication). All participants will follow a strict potassium monitoring plan. If potassium levels begin to rise, we will adjust treatment promptly and use medications to lower potassium if needed. This approach is designed to protect patient safety while allowing us to test the medication.
Anticipated Outcomes: We expect that finerenone will lower protein levels in the urine after six months compared with placebo. We also expect that, with careful monitoring, the medication can be used safely without causing dangerous potassium levels and this monitoring plan will be well received.
Patient Engagement: Four patient partners helped design this study. They supported the potassium monitoring strategy, including close blood testing and the use of potassium-lowering medications when needed. They agreed that reducing protein in the urine is a meaningful outcome because it signals slower kidney damage. They also shared that patients may be willing to accept some risk if there is a real chance to delay kidney failure and avoid dialysis.
Relevance: People with stage 4 CKD face limited treatment options and a high risk of kidney failure and heart disease. This study aims to change that. Delaying kidney failure could mean more time without dialysis, fewer hospital visits, improved quality of life, and lower healthcare costs.
Conclusion: People with stage 4 CKD are at high risk but have been underrepresented in research. The REDEFINE-CKD pilot study will test whether finerenone can safely reduce kidney damage in this vulnerable group using careful potassium monitoring. This study will lay the groundwork for larger trials to definitively determine the effects of finerenone in this population.