The purpose of this protocol is to examine the effects of the sodium-glucose cotransporter 2 (SGLT2) inhibitor canagliflozin on intrarenal transcripts of energy metabolism in adults with type 2 diabetes and early diabetic kidney disease (DKD) via an open-label non-randomized mechanistic trial. This trial will enroll 40 participants who will receive 100 mg of canagliflozin daily for six (6) months in addition to standard of care. The primary objective of this study is to determine whether canagliflozin affects intrarenal transcripts of energy metabolism in adults with type 2 diabetes and early DKD. The primary outcomes measure will be change in transcripts as assessed by single-cell RNA sequencing of kidney biopsy specimens obtained at study entry and after 6 months of study drug. Secondary outcomes include assessing the effects of canagliflozin on structural progression of DKD assessed by morphometric examination of kidney tissue specimens from the paired research biopsies. Additional secondary outcomes include measures of glomerular filtration rate (GFR) and renal plasma flow (RPF) as well as multiparametric kidney MRI. Magnetic resonance imaging of the kidneys will be performed prior to each biopsy to correlate the molecular and structural damage seen at kidney biopsy with the level of perfusion, oxygen availability and fibrosis detected by imaging. Imaging of the kidneys will be done as near to the time of each kidney biopsy as possible. Participants will be followed annually after completion of the mechanistic clinical trial until death or development of end-stage kidney disease.~Of note, participants will be offered the option of staying on the SGLT2 inhibitor free of charge until Jan 2028 to obtain the long-term impact of SGLT2 on GFR and proteinuria. This expansion will be optional and include annual remote visits and extraction of serum creatinine and urine albumin-to-creatinine ratio from their electronic health records.
Canagliflozin is an oral drug which is currently approved for use in patients with type 2 diabetes by the US Food and Drug Administration (FDA). Canagliflozin acts by increasing salt and sugar loss in the urine, and has shown to protect heart, kidney, and blood vessel function in patients with type 2 diabetes. However, it is unknown how canagliflozin protects the kidneys from disease. Therefore, this study plans to learn more about how canagliflozin works to protect against diabetic kidney disease in adults with type 2 diabetes. This study will use state-of-the-art kidney imaging, kidney biopsies and detailed testing of kidney function to determine the mechanisms of protection afforded by canagliflozin.