Merck (MRK) has sold Cosopt (dorzolamide hydrochloride/timolol maleate), an opthalmic drug indicated for the treatment of ocular hypertension and open-angle glaucoma, since 1998. In October 2005, Hi-Tech Pharmacal filed the first ANDA for a generic version of Cosopt with paragraph IV certifications to the Orange Book-listed patents: U.S. Patent Nos. 4,797,413; 6,248,735; and 6,316,443.
In January 2006, Merck sued Hi-Tech (HITK), asserting infringement of the '413 patent but not the '735 or '443 patents. On April 18, 2006, Merck filed a statutory disclaimer of the '735 and '443 patents with the USPTO, effectively dedicating its rights under the patents to the public. Shortly thereafter, on April 25, Merck wrote to the FDA and requested that the agency delist those two patents from the Orange Book. The FDA, however, did not delist the patents - indeed the patents remain listed today.
In October 2006, Apotex sent Merck a letter notifying it that Apotex had filed an ANDA for a generic version of Cosopt with paragraph IV certifications to all three Orange Book-listed patents. In response, Merck sued Apotex in December 2006, again asserting infringement of the '413 patent but not the '735 or '443 patents. Apotex agreed to be bound by the court decision on the '413 patent in the Hi-Tech case, but pursued declaratory judgment counterclaims of invalidity of the disclaimed patents. On March 29, 2007, the Federal Circuit affirmed the patent term of the '413 patent, leaving only Apotex's counterclaims on the disclaimed '735 and '443 patents in the case.
Shortly after the Federal Circuit decision on the '413 patent, Merck moved under Fed. R. Civ. P. 12(b)(1) to dismiss Apotex's counterclaims of invalidity of the '735 and '443 patents for lack of subject matter jurisdiction. In an opinion (pdf file) released earlier this month, the district court granted Merck's motion to dismiss, concluding: "because Merck has formally disclaimed the '735 and '443 patents, and can no longer enforce any claims as to these patents, there is no justiciable case or controversy to support jurisdiction in an action for a declaratory judgment here." Apotex has appealed the decision to the Federal Circuit.
Merck brief in support of motion to dismiss (pdf file) Apotex brief in opposition to motion (pdf file) (pdf file) Merck reply brief (pdf file)