Efficacy and Tolerability of Combination Therapy Versus Monotherapy with Candesartan and/or Amlodipine for Dose Finding in Essential Hypertension: A Phase II Multicenter, Randomized, Double-blind Clinical Trial

Purpose Intensive blood pressure (BP) lowering is important for the treatment of hypertension; however, it has been a challenge to achieve target BP in many patients. The purpose of this study was to explore the optimal dosage of a fixed-dose combination of candesartan cilexetil (CAN) and amlodipine besylate (AML), by examining the tolerability and efficacy of CAN/AML combination therapy compared with those of monotherapy with either drug in patients with essential hypertension. Methods This Phase II multicenter, randomized, double-blind clinical trial enrolled patients aged 19 years or older with essential hypertension, defined as a mean sitting diastolic BP (msDBP) between 95 and 115 mm Hg, and a mean sitting systolic BP (msSBP) of <200 mm Hg after a 2-week placebo run-in period. A total of 635 patients were screened, of whom 439 were randomized to receive treatment; 425 patients were included in the full analysis set (combination therapy, 212; monotherapy, 213). Participants were randomly assigned to receive 1 of 8 treatments: CAN (8 or 16 mg), AML (5 or 10 mg), CAN/AML (8 mg/5 mg, 8 mg/10 mg, 16 mg/5 mg, or 16 mg/10 mg), once daily for 8 weeks. Findings After 8 weeks of treatment, changes in msDBP were significantly greater in the groups receiving CAN/AML combination therapies compared with monotherapies at matched doses, with the exception of CAN 8 mg/AML 10 mg versus AML 10 mg. The response to treatment and the achievement of target BP (both msSBP and msDBP) at week 8 were significantly greater overall in the groups that received combination therapy versus monotherapy. All medications were relatively well tolerated in each group. Implications Eight-week administration of CAN/AML (8 mg/5 mg, 16 mg/5 mg, and 16 mg/10 mg) resulted in a significantly greater BP reduction than that with CAN or AML monotherapy, and was determined to be well tolerated. ClinicalTrials.gov identifier: NCT02944734.