Swiss drugmaker Novartis, one of the only companies still developing new drugs for high blood pressure, unveiled new clinical data on two products yesterday that suggest its faith in the category may pay off.

Phase III results with Rasilez (aliskiren) – Novartis and Speedel’s first-in-class renin inhibitor, showed that it was effective in controlling blood pressure over a 24-hour period, both alone and in combination with the diuretic hydrochlorothiazide, and was no different to placebo in terms of tolerability.

The data back up earlier results demonstrating Rasilez’ blood pressure-lowering activity, and crucially could give the product an edge in the massive but mature market for antihypertensives.

This market is well-served with a broad range of compound classes, many of which have already lost patent protection. But patients with hypertension often have to swap between classes because of side effects or difficulties in meeting treatment goals. This means Rasilez’ tolerability and durable effects on blood pressure, particularly its ability to control the increases in blood pressure that can occur in the early hours of the morning, could allow it to capture market share quickly, according to analysts.

About 40% of those diagnosed with the disease do not achieve adequate control of their high blood pressure. Meanwhile, another potential advantage could be its potential to offer improved end-organ protection due to its inhibition of plasma renin activity, an emerging risk factor for cardiovascular disease.

The Rasilez data, which were presented at the American Society of Hypertension annual meeting in New York, showed that the agent reduced both ambulatory systolic and diastolic blood pressure measurements over 24 hours. And at the highest dose tested (300mg) the trough-to-peak ratio for lowering diastolic blood pressure was 0.98, indicating that reductions were consistent and nearly identical over the entire period.

Novartis already markets a member of one of the newer clases of antihypertensive agents - an angiotensin II receptor antagonist called Diovan (valsartan) - that had sales of $3.7 billion last year and is the leading AIIRA in the USA. Rasilez has been tipped to add at least $1 billion to the firm’s antihypertensive sales, and Denise Anderson, an analyst at Zurich-based Kepler Equities, expects sales from Novartis' portfolio of antihypertensives to rise to $7.7 billion by 2009 from $4.8 billion in 2005.

From 2009, the first of the angiotensin II receptor antagonists are due to lose patent protection, which could lead to pricing pressure on the franchise. Diovan itself has patent protection out to 2012.

Meanwhile, Novartis has given the first view of pivotal data on its new combination product Exforge, comprised of valsartan with Pfizer’s amlodipine, which has already lost patent protection in a number of countries with the USA due to follow suit next year.

In the Phase III study, patients with moderate-to-severe high blood pressure experienced drops of 35 to 43mmHg, with 80% of patients treated with Exforge for six weeks reached the recommended goal of mean sitting diastolic blood pressure of less than 90mmHg.

This profile is expected to make Exforge a useful product for patients with uncontrolled hypertension, a niche which could bring in more than $500 million a year in sales at its peak.

Rasilez has been filed for approval in the USA, and a European filing should occur later this year, according to Novartis. Exforge has been submitted in both territories.