Strongest reduction seen in risk of new macroalbuminuria
One in three adults with diabetes has CKD, according to a press release issued by the ADA. Therefore, there is a need for therapies to reduce the development and progression of CKD in patients with type 2 diabetes.
The prespecified analysis of SUPRESS-4 investigated potential renoprotective effects of tirzepatide.
The trial enrolled 1,995 patients with type 2 diabetes who were at increased risk of cardiovascular disease. The patients had a mean age of 63.6 years and a mean hemoglobin A1c of 8.5%.
Most patients had normal kidney function. The mean eGFR based on the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation was 81.3 mL/min per 1.73 m2.
Few patients (17%) had moderately or severely reduced kidney function (eGFR <60 mL/min per 1.73 m2). Around a quarter of the patients (28%) had microalbuminuria (UACR 30-300 mg/g) and 8% had macroalbuminuria (UACR >300 mg/g).
The patients were randomized to receive a weekly injection of 5, 10, or 15 mg tirzepatide or a daily individualized injection of insulin glargine starting at 10 IU/day at bedtime, titrated to a fasting blood glucose <100 mg/dL, in addition to existing oral glucose-lowering agents. The primary outcomes in the subanalysis were:
- Endpoint 1: a composite of ≥40% decline in eGFR from baseline, renal death, progression to ESKD, and new-onset macroalbuminuria.
- Endpoint 2: the same as endpoint 1 excluding new-onset macroalbuminuria.
During a median follow up of 85 weeks and up to 104 weeks, patients who received tirzepatide versus insulin glargine were significantly less likely to reach endpoint 1 but not endpoint 2.
In addition, tirzepatide “very strongly” reduced the risk of new-onset macroalbuminuria, compared to insulin glargine, by approximately 60% in the complete study cohort (hazard ratio, 0.41; P < .05), Dr. Limonte noted.
Tirzepatide also reduced the risk of a >40% decline in eGFR, but this effect was not statistically significant, possibly because this outcome was underpowered. There were also too few kidney deaths and progressions to ESKD to meaningfully assess the effects of tirzepatide on these outcomes.
Therefore, Dr. Limonte noted, “it is likely that tirzepatide’s significant benefit on composite endpoint 1 was largely driven by this agent’s impact on reducing macroalbuminuria onset [explaining why a significant benefit was not seen with composite endpoint 2, which excluded new-onset macroalbuminuria].”
The study was funded by Eli Lilly. Dr. Heerspink disclosed that he is a consultant for AstraZeneca, Bayer AG, Boehringer Ingelheim, Chinook Therapeutics, CSL Behring, Gilead Sciences, Goldfinch Bio, Janssen Research & Development, Mitsubishi Tanabe Pharma, Mundipharma, and Traveere Pharmaceuticals, and has received research support from AstraZeneca, Boehringer Ingelheim, and Novo Nordisk.
Dr. Limonte disclosed that she receives funds from the American Kidney Fund’s Clinical Scientist in Nephrology Award.
A version of this article first appeared on Medscape.com.