The U.S. Patent and Trademark Office (PTO) ordered the reexamination of Merck’s biggest selling product, Singulair. The challenged patent, U.S. Patent No. 5,565,473 (“Unsaturated Hydroxyalkylquinoline Acids as Leukotriene Antagonists,” issued October 15, 1996), covers montelukast sodium, the active ingredient in the $4.5 billion-a-year allergy and asthma drug.
The request for reexam, No. 90/009,432, was made by an online community called Article One Partners LLC that recruits scientists worldwide to look for evidence patents have been improperly issued. Article One Partners, a for-profit group formed by a group of patent attorneys and financial advisors, offered a $50,000 bounty for anyone who could come up with invalidating prior art.
The winning Advisors were a U.S. graduate student and an Advisor from Columbia, South America. The U.S. graduate student was first to submit winning prior art (the Young journal article) and earned $35,000. The South American Advisor was the second to submit winning prior art (the Young patent), earning $15,000.
The USPTO’s reexamination is in parallel to a pending court case where a ruling is expected from a trial in which Merck is asserting the patent against Teva Pharmaceuticals, who is challenging the patent. The ‘473 patent was originally set to expire in 2010 but was eligible for patent term extension under 35 U.S.C. § 156 of 430 days. The patent would expire on February 3,2012, if it survives.
Generic drug makers probably shouldn’t start stocking shelves with their own version of the drug just yet. For starters, the USPTO is taking about 24 months to decide ex parte reexaminations. In addition, claims 1, 7, 18-22 (as asserted by Merck against Teva) could survive the reexam as valid and enforceable in one form or another. Even if it does not issue in its current state, it could issue with modified claims that provide substantial coverage necessary to protect the product.
The determination of winners by Article One was by analysis, including review and analysis of an independent law firm and a separate independent expert, leading Article One to reach the opinion that the prior art raises a substantial new question of validity for the ‘473 patent.
For “a substantial new question of patentability” to be present in order to provoke a reexamination, it is only necessary a challenger show that:
- The prior art patents and/or printed publications raise a substantial question of patentability regarding at least one claim, i.e., the teaching of the prior art) patents and printed publications is such that a reasonable examiner would consider the teaching to be important in deciding whether or not the claim is patentable; it is not necessary that the prior art establish a prima facie case of unpatentability; and
- The same question of patentability as to the claim has not been decided by the Office in a previous examination or pending reexamination of the patent or in a final holding of invalidity by the Federal Courts in a decision on the merits involving the claim.
In regards to the Young References (US 5,104,882), the patent generically discloses diarylstrylquinoline diacids and pharmaceutical composition thereof. These compounds are leukotriene antagonists and inhibitors of leukotriene biosynthesis and are useful for treating asthma.
The Examiner determined that there is a substantial likelihood that a reasonable examiner would consider this teaching important in deciding whether or not claims 1, 7, 18-22 are patentable. The reference was cited, but was not applied during the prosecution of the patent. It is now being viewed in new light in combination with other references including “The Development of New Anti- Leukotriene Drugs: L-648,051 and L-649,923, Specific Leukotriene D4 Antagonists,” by Robert Young.
So, what does Article One get out of all this? From their web site:
How does AOP make money?
AOP has 2 streams of revenue: 1. Our prior art collections can be sold directly to parties interested in the subject patent(s). 2. The research also allows us to execute market trades based on the expert analysis and opinions drawn from our Advisors’ research.
