CHICAGO — Nearly three-fourths of patients with uncontrolled hypertension on monotherapy achieved national blood pressure targets on a fixed-dose combination of amlodipine and valsartan that will soon be available, Dr. Joseph L. Izzo Jr. reported at the annual meeting of the American Society of Hypertension.
Two different formulations of Novartis' single-tablet combination drug, which was approved in June and will be marketed as Exforge, were evaluated in a double-blind, multicenter study that randomized 443 patients to amlodipine 5 mg/valsartan 160 mg and 451 patients to amlodipine 10 mg/valsartan 160 mg. After 8 weeks, hydrochlorothiazide (HCTZ) could be added on, first at 12.5 mg, and then at 25 mg.
The majority of patients, including 145 (16%) of whom had type 2 diabetes, had been previously treated with a β-blocker, angiotensin receptor antagonist, ACE inhibitor, calcium channel blocker, or diuretic.
At admission, their mean age was 58 years, more than 90% were white, and their mean BP was 150/90 mm Hg, said Dr. Izzo, who has received research support and is a consultant for Novartis, which sponsored the study.
The study's primary end point was the proportion of patients after 8 and 16 weeks who had reached a BP of 140/90 mm Hg or 130/80 mm Hg for those with diabetes—the currently recommended dual BP targets in the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7).
In an intent-to-treat analysis at week 16, 322 of 440 patients (73%) on the 5- mg/160-mg dose and 338 of 449 patients (75%) on the 10-mg/160-mg dose achieved the dual JNC7 targets, the investigators reported.
Among those with diabetes, 25 of the 61 patients (41%) on the low-dose combination and 27 of the 59 patients (46%) on the high-dose combination reached a BP of less than 130 mm Hg.
Switching patients to the combination therapy resulted in an average additional 20-mm Hg drop in systolic BP, compared with reductions seen with their previous medications. said Dr. Izzo, professor of medicine, State University of New York at Buffalo, said at a press briefing.
BP control rates were similar when stratified by prior medication, age, or ethnicity. There was little increased response after 8 weeks that could be attributed to the addition of HCTZ therapy.
Adverse events were similar between groups, although the incidence of edema was higher with the 10-mg/160-mg dose than with the lower dose (25% vs. 8%).
Exforge was approved by the Food and Drug Administration last month. It is indicated for the treatment of hypertension in patients whose blood pressure has not been adequately controlled with a calcium channel blocker or angiotensin II receptor blocker alone. The pills will be available in four strengths: 5 mg amlodipine/60 mg valsartan, 10 mg/160 mg, 5 mg/320 mg, and 10 mg/320 mg. Exforge has been launched by Novartis in select European countries. The products will be available in the United States no earlier than Sept. 25 of this year, the FDA specified in a December 2006 letter to Novartis, because amlodipine (Norvasc, Pfizer) remains under patent protection until then.