RULING ON LIPITOR MAY AFFECT INVESTOR REACTION TO NEXIUM CHALLENGE
An upcoming U.S. patent ruling on Lipitor could affect how investors react to
a bid to market a generic version of AstraZeneca's ulcer drug Nexium, according
to one analyst.
British drugmaker AstraZeneca said recently that Ranbaxy Laboratories is seeking
FDA approval to market 20- and 40-mg capsules of generic Nexium (esomeprazole
magnesium), which had 2004 sales of $3.8 billion.
"A decision is expected on Lipitor's '995 isomer patent, which could affect
sentiment toward the potential strength of the Nexium isomer patent," wrote
Merrill Lynch analyst Graham Parry in a recent research note.
A British court last week struck down the equivalent of Pfizer's '995 patent,
which covers the form of atorvastatin that is sold as Lipitor (atorvastatin
calcium), but upheld the equivalent of U.S. patent '893, a broad patent covering
the range of atorvastatin compounds that includes Lipitor.
AstraZeneca has 45 days to file a patent lawsuit against Ranbaxy, which would
automatically trigger a 30-month stay under the Hatch-Waxman Act. This would
mean Ranbaxy would not be able to launch its product until either the expiration
of the stay or a court ruling in favor of Ranbaxy.
Parry said he expects Ranbaxy to lose its bid, based on AstraZeneca's "robust"
isomer patent. He added that even if Ranbaxy wins the suit, the earliest it
could launch generic Nexium would be after the expiration of the 30-month stay,
in June 2008.