Comparison of Efficacy of Long‐term Oral Treatment with Telmisartan and Benazepril in Cats with Chronic Kidney Disease

BACKGROUND The efficacy and benefits of telmisartan in cats with chronic kidney disease (CKD) have not previously been reported. HYPOTHESIS Long-term treatment of cats with CKD using telmisartan decreases urine protein-to-creatinine ratio (UP/C) similar to benazepril. ANIMALS Two-hundred and twenty-four client-owned adult cats with CKD. METHODS Prospective, multicenter, controlled, randomized, parallel group, blinded clinical trial with noninferiority design. Cats were allocated in a 1:1 ratio to either telmisartan (1 mg/kg; n = 112) or benazepril (0.5-1.0 mg/kg; n = 112) PO q24 h. The primary endpoint was prospectively defined as the change in proteinuria (benazepril:telmisartan) based on a log transformed weighted average of UP/C change from baseline (AUC 0→t/t) as a percentage compared using a confidence interval (CI) approach. Changes of UP/C from baseline were assessed on all study days and corrected for multiple comparisons. RESULTS Telmisartan proved noninferior to benazepril in controlling proteinuria (CI, -0.035 to 0.268). At Day 180, UP/C compared to baseline in the telmisartan group was significantly lower (-0.05 ± 0.31; P = .016), whereas in the benazepril group the change (-0.02 ± 0.48) was not statistically significant (P = .136). Similar results were obtained at all assessment points with significant decrease in UP/C occurring with telmisartan but not benazepril. CONCLUSION AND CLINICAL IMPORTANCE Both telmisartan and benazepril were well tolerated and safe. Telmisartan proved to be noninferior to benazepril and significantly decreased proteinuria relative to baseline at all assessment points whereas benazepril did not.