Generic Norvasc May Launch Sooner Than Expected Following Appellate Court Ruling
This article was originally published in The Pink Sheet Daily
Executive Summary
Pfizer’s hypertension treatment was predicted to go generic in September.
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Generics of Pfizer's blockbuster hypertension drug Norvasc (amlodipine) could hit the market months ahead of the drug's key patent and exclusivity expiration in September after a federal appeals court ruled the patent invalid March 22. By invalidating Patent No. 4,879,303, covering amlodipine besylate, the U.S. Court of Appeals for the Federal Circuit could open the door for the launch of generic versions soon. Mylan is the only generic drug maker to have received final ANDA approval for amlodipine and has claimed it has 180-day exclusivity (1 (Also see "Mylan Granted 180-Day Exclusivity On Norvasc" - Pink Sheet, 4 Oct, 2005.)). FDA's "Orange Book" lists the '303 patent as valid until March 25, 2007, though it has pediatric exclusivity extending to Sept. 25. The appeals court ruling involved a patent suit filed by Pfizer against Canadian drug maker Apotex, which has received tentative ANDA approval for the drug. However, Apotex said March 22 that because a limiting patent on Norvasc will expire in a few days, "no company will have exclusivity over the product," and that it intends to launch amlodipine "in the very near future." In a separate case filed by Pfizer against Mylan, the U.S. District Court for the Western District of Pennsylvania ruled in February that the '303 patent was valid. The court issued an injunction barring Mylan from launching a generic until September. Mylan has appealed that court decision. Several Wall Street analysts indicated the appellate decision could lead to an imminent launch of amlodipine generics. The "ruling against Norvasc makes it likely that generics launch as soon as next week," Prudential analyst Tim Anderson predicted in a March 22 note. For Pfizer, the earlier generic entry could cost the company approximately $1 billion in sales in 2007, he indicated. Merrill Lynch analyst Gregg Gilbert noted that if Mylan launches its version soon, the drug could generate $288 million in sales during an assumed 180-day exclusivity period. Pfizer said it might seek a reconsideration of the decision. Norvasc is the firm's second-best selling drug with 2006 sales of $4.87 billion. Another company that could also stand to benefit is Novartis, which has been holding off on launching its hypertension treatment Exforge , a combination of Norvasc and the Swiss firm's Diovan (valsartan) until the amlodipine patent and exclusivity expires (2 (Also see "Novartis To Launch Exforge In September 2007" - Pink Sheet, 22 Dec, 2006.)). Of Exforge, Prudential's Anderson added, "The presumed September '07 launch could now be brought forward to March/April '07, which is a slight positive for Novartis." Apotex Chief Executive Officer Barry Sherman also indicated that the ruling could impact the firm's high-profile lawsuit with Bristol-Myers Squibb over generics of Plavix (clopidogrel) (3 (Also see "Sanofi/Bristol Plavix Patent Suit To Begin Against Apotex" - Pink Sheet, 19 Jan, 2007.)). "Today's decision also has implications for the outcome of the clopidogrel case as some of the same legal principles are at stake in that trial," he said. - Jonathan M. Block ([email protected]) |