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Merck Asks US To Reconsider Singulair Patent Rejection

By Peter Loftus, Of DOW JONES NEWSWIRES

Merck & Co. (MRK) has asked the U.S. Patent and Trademark Office to reconsider its tentative rejection of Merck's patent for the blockbuster asthma drug Singulair.

In early September, after re-examining the Singulair patent, the PTO issued a "nonfinal action" rejecting key claims in the patent, which is due to expire in 2012. The PTO said the claims were "unpatentable" partly because they were anticipated by another patent. The PTO views so-called double-patenting as an unjustified extension of patent exclusivity beyond the term of a patent.

The PTO had launched its re-examination in May at the request of Article One Partners LLC, an online patent-research service that said it uncovered new information raising questions about the validity of the Singulair patent, which was issued in the 1990s.

Still, the PTO's tentative rejection of the patent might not result in generic competition anytime soon for Singulair, which is Merck's best-selling product, with $3.4 billion in sales for the first nine months of 2009. There is precedent for the PTO reversing itself in final decisions, after patent holders provide more information.

Earlier this year, for instance, the PTO granted the reissue of a key patent for Pfizer Inc.'s (PFE) Lipitor cholesterol drug, after initially rejecting Pfizer's request for a reissuance.

What's more, a federal judge in New Jersey upheld the validity of the Singulair patent in August, rejecting a challenge by generics manufacturer Teva Pharmaceutical Industries Ltd. (TEVA), which has since appealed the ruling.

Last week, Merck filed its response disputing the PTO's initial rejection, essentially asking that the claims be upheld.

"This is standard action in these matters," Merck spokesman Ron Rogers said Monday. He added that such re-exams usually take about 24 months to complete.

Merck shares rose 80 cents, or 2.45%, to $33.39 in Monday afternoon trading.

-Peter Loftus; Dow Jones Newswires; 215-656-8289; peter.loftus@dowjones.com

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  11-09-091548ET
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