It isn't often that the two biggest of Big Pharma find themselves in a patent fight. Usually, it's a branded drugmaker fighting off a generics challenge from a copycat drugmaker. But this time it's Pfizer ($PFE) and Merck ($MRK), in a tussle over the rights to cholesterol-fighter Lipitor.
Pfizer sued Merck to block a new Lipitor-plus-Zetia combination pill. The new drug would be a sort of cousin to Merck's Vytorin, which fuses its own statin drug Zocor (simvastatin) with Zetia, its cholesterol treatment that works via a different mechanism. As the Wall Street Journal notes, Zetia brought in $2.3 billion in 2010 on its own, and Vytorin accounted for $2 billion in sales. If analyst estimates are correct, a Lipitor/Zetia version could bring in $500 million by 2015.
Pfizer-watchers know that Lipitor faces generic competition November 30. Ranbaxy Laboratories has a license from Pfizer to sell its version beginning on that date, thanks to a patent settlement between the two companies. Plus, Pfizer has agreed to supply an authorized generic to Watson Laboratories beginning on the same day. But Pfizer has some patents on Lipitor that don't expire for a few years, and it's citing one of these in its case against Merck, the WSJ reports.
Pfizer has used the same patent--which covers Lipitor's crystalline structure and expires in 2017--in other lawsuits, too. Merck says its combo pill won't infringe on that patent. Pfizer, of course, claims it does. The lawsuit triggers a 30-month regulatory delay, which brings us to one potential problem: efficacy questions about Vytorin, which have plagued the pill since a study found no significant difference in arterial narrowing with Vytorin than with Zocor used alone. A new outcomes study is due in 2013, and if that data goes against Vytorin, then a Lipitor/Zetia combo may not thrill the market if and when it does make its debut.
- read the WSJ piece