Singulair is Merck’s best-selling drug, with sales of nearly $1.1 billion in the third quarter of 2009. However, Merck’ patent covering Singulair has also been hotly contested in court, at the FDA, and, most recently, at the USPTO. The Singulair patent, U.S. Patent No. 5,565,473, issued in 1996, covers the basic compound as well as a method of treating asthma. The ‘473 patent has been the subject of ongoing litigation between Merck and generic manufacturer Teva Pharmaceuticals. Merck filed three suits against Teva in April of 2007, May of 2007, and January of 2009, all in the U.S. District Court for the District of New Jersey, claiming that Teva infringed the ‘473 patent by filing an ANDA for generic Singulair. Because the suits all asserted infringement of the ‘473 patent, the later two suits were stayed pending a final decision on the merits in the first suit. On August 19, 2009, Judge Garrett E. Brown of the U.S. District Court for the District of New Jersey ruled that Teva’s generic drug would infringe Merck’s ‘473 patent, and ordered the FDA to stay market approval of the generic version of Singulair pending expiration of the ‘473 patent in 2012. Unfortunately for Merck, the success in the District Court represents only one front of battle for defending the validity of the ‘473 patent. On April 27, 2009, four months prior to Judge Brown’s ruling, an ex parte reexamination request was filed for the ‘473 patent by Article One Partners LLC, a global research community which rewards Advisors for finding prior art to invalidate patents. The ex parte examination request was submitted with eight prior art documents in which Article One set forth over 276 pages of obviousness arguments. The request was granted by the USPTO on May 28, 2009. Despite the painstaking efforts by Article One in their Request for Ex Parte Reexamination, on September 3, 2009, the USPTO issued a single obvious-type double patenting rejection over lapsed U.S. Patent No. 5,428,033 in view of U.S. Patent No. 5,104,882. Despite vehement arguments that the claims of the ‘473 patent are patentably distinct over the claims of the ‘033 patent, Merck filed a terminal disclaimer on November 2, 2009 to obviate the obvious-type double patenting rejection. The terminal disclaimer would seemingly result in the ‘473 patent expiring on June 27, 2012, which is the expiration date of the ‘033 patent as defined under 35 U.S.C. 154 and 173. There being no further issues unresolved in the reexamination of the ‘473 patent, it appears that a Notice of Intent to issue a Reexamination Certificate (NIRC) will be issued by the USPTO to Merck. At $1.1 billion per quarter, at first glance the filing of the terminal disclaimer over the ‘033 patent would appear to be good news for Teva. However, the newly filed terminal disclaimer will not affect the expiration date of the ‘473 patent. The terminal disclaimer filed in the reexamination proceedings disclaimed the patent term beyond June 27, 2012, but the statutory patent term of ‘473 will have already expired well prior to this date in view of a terminal disclaimer filed over U.S. Patent No. 5,266,568 during the original prosecution of the ‘473 patent resulting in an already shortened patent term to November 30, 2010. It is worth noting that the terminal disclaimer will also have no affect on the ultimate expiration of the ‘473 patent on February 3, 2012, which takes into account a 430-day extension granted under § 156 for delays in FDA regulatory review. In March 2007 the Court of Appeals for the Federal Circuit held that if a patent is subject to a terminal disclaimer, the term extensions for regulatory review granted by section § 156 of the Patent Law are added on after the terminal disclaimer date. Merck & Co. v. Hi-Tech Pharmacal Co., 82 USPQ2d 1203, 1208 (Fed. Cir. 2007).