Background: Renin-angiotensin system (RAS) blockade with ACE inhibitor and/or angiotensin receptor blocker therapy can lead to increased potassium levels, hence the need to assess dual blockade involving a direct renin inhibitor. Here we report the results of a pre-planned 6-month interim analysis of a long-term, open-label study examining the safety, tolerability and efficacy of the aliskiren/valsartan 300/320-mg combination in patients with hypertension.
Methods: A total of 601 patients with hypertension (msDBP > or = 90 and < 110 mmHg) received a combination of aliskiren/valsartan 150/160 mg for 2 weeks followed by forced titration to aliskiren/valsartan 300/320 mg once daily for a targeted duration of 52 weeks. Optional hydrochlorothiazide (HCTZ) addition was allowed from week 8 for inadequate BP control (> or = 140/90 mmHg). The primary objective was to assess the safety of combination therapy; potassium elevations were a predefined safety outcome. BP was measured at regular intervals during the study.
Results: At the 6-month cut-off date, 512 patients (85.2%) were still ongoing with study treatment, and 192 patients had received at least one dose of HCTZ add-on during this period. Combination therapy was generally well-tolerated; the most commonly reported adverse events were headache (7.5%), dizziness (7.3%) and nasopharyngitis (7.2%). Ten patients (2.5%) receiving aliskiren/valsartan and two patients (1.0%) receiving aliskiren/valsartan/HCTZ had serum potassium elevations > 5.5 mmol/L. Only one patient (0.2%) exhibited potassium levels > or = 6.0 mmol/L during this period and the patient was treated with aliskiren/valsartan. Mean msSBP/DBP reductions of 22.3/14.4 mmHg were observed at 6-month endpoint (LOCF analysis) and 73.4% of patients achieved BP control (< 140/90 mmHg; LOCF).
Conclusions: Although lack of an active comparator group is a limitation of the study, our findings show that long-term treatment with the aliskiren/valsartan 300/320-mg combination provided clinically significant BP lowering, was well-tolerated and was associated with a very low rate of potassium elevations in patients with hypertension.