Opinion ID: 208134
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Heading: introduction

Text: This case is a patent law appeal from a district court order granting summary judgment of invalidity based on anticipation and obviousness. Ortho-McNeil Pharmaceutical (“Ortho”) brought suit against Teva Pharmaceuticals Industries (“Teva”) and Caraco Pharmaceutical Laboratories (“Caraco”) alleging infringement of U.S. Reissued Patent 39,221 (“RE’221”), directed to a combination tramadol and acetaminophen composition for use in prescription pain relief. We vacate-in-part, affimin-part, and remand. Acetaminophen is a popular non-opioid pain reliever, more commonly known by the brand name Tylenol®. Acetaminophen has a poorly understood mechanism of action, and interacts with other drugs in ways that could not be predicted in 1990. Nonetheless, it was a popular pain reliever and Ortho had a history of experimenting with combining acetaminophen and other drugs. Tramadol is an atypical weak opioid with an unclear mechanism of action. Tramadol and methods of making and using it were first described in U.S. Patent No. 3,652,589 to Flick. Flick mentions that tramadol can be combined with other analgesics, and often exhibits synergistic effects. The specification of Flick also includes 23 working examples. The first 22 examples describe different tramadol formulations. Example 23 discloses a combination of tramadol, p-acetamino-phenol, pentobarbital sodium, and ethoxy benzamide. In 1990, Tramadol was known to have several serious side effects, and for that reason was commonly administered through gradual dose titration. 2008-1549, -1550 2 Ortho first claimed a combination tramadol and acetaminophen tablet in 1990, in U.S. Patent No. 5,336,691 (“’691 patent”). The patent described one benefit of the claimed composition as a synergistic effect between tramadol and acetaminophen. Ortho received FDA approval for such a combination tablet and marketed its product as Ultracet®. Ultracet® immediately became the fastest growing prescription pain reliever and enjoyed considerable commercial success. Several generic drug companies filed abbreviated new drug applications (“ANDAs”) to market generic versions of Ultracet®. Ortho brought multiple different lawsuits against these companies asserting the ’691 patent against the ANDAs. In pretrial motions, several of the drug companies alleged that the ’691 patent was invalid for anticipation and obviousness based on Flick and other references. During the course of litigation, Ortho discovered that the p-acetamino-phenol mentioned in the Flick patent was actually an archaic name for acetaminophen. The ratio of tramadol to p-acetamino-phenol in the four-compound combination of Flick’s example 23 is 1:10, which falls within the scope of some of the claims of the ’691 patent. In light of the cited references and the fact that p-acetamino-phenol is acetaminophen, Ortho sought reexamination and reissue of the ’691 patent. Ortho submitted to the examiner the relevant prior art, a summary judgment motion submitted by Kali Laboratories, and a letter submitted by Barr Pharmaceuticals arguing anticipation and obviousness of the ’691 patent. Other prior art cited to the examiner during reissue proceedings and to the district court includes a series of German publications based on the WHO Cancer Pain Guidelines (hereinafter “the German references”). Collectively, these articles teach a 2008-1549, -1550 3 method of managing cancer pain using a ladder approach aimed at customizing a coadministration of pain relievers and dosing regimens to meet the needs of each patient. The strengths of the medications and the dosages increase as the prescriber moves up the ladder. The middle rung of the ladder includes a non-opioid analgesic coadministered with a weak opioid. None of the German references mentions synergy. In reissue proceedings for the ’691 patent, Ortho canceled all but one of the asserted claims and redrafted them to narrow the scope of the invention and attempt to avoid the cited prior art references. Ortho also argued to the examiner that one of ordinary skill in the art at the time of filing would not understand the prior art to disclose the claimed invention as amended. The examiner ultimately allowed several redrafted claims and the one previously allowed claim to reissue as RE’221. While the reissue proceedings were pending, Teva and Caraco filed summary judgment motions for invalidity and non-infringement of claim 6 of the ’691 patent. Claim 6 was the one original claim allowed in RE’221, amended to independent form. Ortho then amended its complaints to assert the new reissue claims as well as RE’221 claim 6 against Teva and Caraco (among others) in the ongoing ANDA litigation between the parties. Ortho’s cases against Teva and Caraco were then consolidated. Teva and Caraco filed summary judgment motions for invalidity and noninfringement, asserting that RE’221 was anticipated and rendered obvious by Flick and the German references. Ortho disputed Teva’s and Caraco’s interpretations of the prior art disclosures and submitted uncontroverted expert testimony explaining that one of skill in the art at the time of the original filing would not understand Flick, or the German references to disclose or render obvious the claimed invention. 2008-1549, -1550 4 On August 12, 2008, the district court granted summary judgment invalidating RE’221 claims 43-48, 51, 54, 67, 69, 72, and 74 as obvious over the prior art, and invalidating claim 6 as anticipated and obvious over the prior art. 1 Ortho-McNeil timely filed its notice of appeal on August 25, 2008. This court has jurisdiction pursuant to 28 U.S.C. § 1295(a)(1).