Efficacy and safety of 10-mg azilsartan compared with 8-mg candesartan cilexetil in Japanese patients with hypertension: a randomized crossover non-inferiority trial

We investigated whether 10 mg per day of azilsartan, one-half of the normal dosage, would be non-inferior to 8 mg per day of candesartan cilexetil for controlling blood pressure in Japanese patients with hypertension. In this open-label, randomized, crossover trial, 309 hypertensive Japanese adults treated with 8-mg candesartan cilexetil were randomized into two arms and received either 10-mg azilsartan or 8-mg candesartan cilexetil in a crossover manner. The primary efficacy outcome was systolic blood pressure, and the margin of non-inferiority was set to be 2.5 mm Hg. The participants were 67 +/- 11 years old, and 180 (58%) were male. The baseline systolic and diastolic blood pressure levels were 127.1 +/- 13.2 and 69.7 +/- 11.2 mm Hg, respectively. During the study period, the difference in systolic blood pressure between the treatments with 10-mg azilsartan and 8-mg candesartan cilexetil was -1.7 mm Hg, with the two-sided 95% confidence interval (CI) ranged from -3.2 to -0.2 mm Hg. The upper boundary of the 95% CI was below the margin of 2.5 mm Hg, confirming the non-inferiority of 10-mg azilsartan to 8-mg candesartan cilexetil. The difference also reached significance (P = 0.037). The corresponding difference in diastolic blood pressure was -1.4 (95% CI: -2.4 to -0.4) mm Hg (P = 0.006). Treatment with 10-mg azilsartan was similar to 8-mg candesartan cilexetil in its association with rare adverse events. In conclusion, 10-mg azilsartan was non-inferior to 8-mg candesartan cilexetil for controlling systolic blood pressure in Japanese hypertensive patients already being treated with 8-mg candesartan cilexetil.