Novartis' combo hypertension drug approved in US
combination of the world's two most popular hypertension drugs,
taking advantage of rival patent expiries and shoring up its
Exforge, a combination of Novartis' own flagship hypertension drug Diovan (valsartan) and Pfizer's Norvasc (amlodipine), has been granted final US regulatory approval five months after gaining approval across Europe. Exforge has already been made available in nine European countries with further launches planned, but Novartis was unable to pin down when the combination product would be available to patients in the US, merely repeating that it should be available "soon". The company is somewhat dictated to by the timing of patent expiries for Pfizer's Norvasc, and original estimates put the US launch of Exforge in September 2007, after the expiration of market exclusivity for the Pfizer drug. Diovan and Norvasc are the two most prescribed, branded hypertension medicines in their classes. Diovan inhibits angiotensin II, a hormone that causes blood vessels to tighten and narrow, whereas Norvasc is a calcium channel blocker. The combination of the two in Novartis' Exforge product has been shown to be more effective in lowering blood pressure that taking either valsartan or amlodipine alone. In both Europe and the US, Exforge has been approved for patients whose blood pressure is not adequately controlled by through angiotensin receptor blockers or calcium channel blockers. Novartis was not willing to comment on potential revenues generated through sales of its new combination product, but according to the company's annual report, it sees the drug as one of a handful of upcoming products that the firm expects to generate peak sales of over $1bn (€0.75bn). Diovan, as one of the company's key products and the most widely prescribed angiotensin receptor blocker, generated sales of $4.2bn over 2006. Norvasc earned Pfizer a slightly higher sum of $4.9bn, though Novartis has confidently asserted that "Diovan is expected to pass branded amlodipine this year and become the top-selling medication for high blood pressure worldwide". However, with the basic compound patent for the drug facing patent expiry in 2012, Novartis fears that these healthy figures could eventually be eroded over the coming years. "A number of leading products could potentially face generic competition in the coming five to ten years in various markets, particularly in the US and Europe," reads the firm's annual report. "These include the top-selling products of Novartis: the anti-hypertension drugs Diovan [valsartan] and Lotrel [amlodipine besylate and benazepril hydrochloride] as well as the oncology drugs Gleevec/Glivec [imatinib] and Zometa [zoledronic acid]." Making the most of Norvasc's timely patent expiry (currently giving Pfizer such grief) and building on the name and reputation of its already established hypertension drugs therefore makes perfect sense for the Swiss firm, and may offer it a degree of protection when its own patents begin to expire. Exforge is one of a number of products that Novartis is set to launch over the next year, several of which the company anticipate to break the $1bn barrier in terms of annual sales. Expectations for the product are high, with the company claiming that it has the potential to "become the most efficacious agent in the antihypertensive category".