Sunovion Pharma., Inc. v. Teva Pharms. USA, Inc.

Case Name: Sunovion Pharma., Inc. v. Teva Pharms. USA, Inc., No. 2013–1335, 2013 U.S. App. LEXIS 19656 (Fed. Cir. Sept. 26, 2013) (Circuit Judges Lourie, Schall, and Reyna presiding; Opinion by Lourie) (Appeal from D.N.J., Wigenton, J.)

Drug Product and Patent(s)-in-Suit: Lunesta® (eszopiclone); U.S. Patent No. 6,444,673 (“the ’673 patent”)

Nature of the Case and Issue(s) Presented: Sunovion appealed the district court’s opinion granting summary judgment of non-infringement. The ‘673 patent is directed to a pharmaceutical composition of the single-enantiomer drug eszopiclone. Eszopiclone is the (S)-enantiomer of the chemical compound disclosed in the claims, which in its racemic form is known as zopiclone. The FDA requires that each tablet of Lunesta contain not more than (“NMT”) 0.3% of eszopiclone’s corresponding levorotatory enantiomer, (R)-zopiclone. The district court premised its decision in part on the interpretation of the term “essentially free” limitation in the asserted claims and Dr. Reddy’s assurances that it would follow its internal manufacturing guidelines. The district court construed the term “essentially free” to mean “less than 0.25% of the levorotatory isomer.” On appeal, Sunovion argued that the claim limitation should be “largely but not wholly free of the levorotatory isomer, which encompasses greater than approximately 90% dextrorotatory isomer by weight of the total weight of zopiclone.” The Federal Circuit rejected Sunovion’s construction. The term “essentially free” appears only in the claims and does not appear anywhere in the written description. But during prosecution, to overcome an obviousness rejection, the applicant pointed to Example 1, and submitted a co-inventor declaration stating the “pure form” of the dextrorotatory isomer of zopiclone “as described in Example 1” contained “lower than 0.25% of the levorotatory isomer.” Based on those statements and others during prosecution, the Federal Circuit affirmed the district court’s construction. Despite affirming that construction, the Federal Circuit reversed the district court’s finding of non-infringement.

Why Sunovion Prevailed: Dr. Reddy’s amended ANDA seeks FDA approval for generic eszopiclone products with 0.0–0.6% levorotatory isomer. The Federal Circuit stated that this fact alone mandates a finding of infringement since the requested range falls within the term “essentially free.” Dr. Reddy’s argued that it does not infringe because its internal manufacturing guidelines requires its generic eszopiclone products contain at least 0.3% levorotatory isomer. Dr. Reddy’s further provided the district court with a certification that it would only market tablets containing 0.3–0.6% of levorotatory isomer. Lastly, Dr. Reddy’s argued that Sunovion is free to sue Dr. Reddy’s after it launches should Sunovion’s test results reveal a lesser percentage. The Federal Circuit was not persuaded by any of Dr. Reddy’s arguments.

Under the Hatch-Waxman framework, the act of filing an ANDA is the technical act of infringement for jurisdictional purposes. But the ultimate infringement question is determined by traditional patent law principles and focuses on the product that the ANDA applicant is asking the FDA to approve. Dr. Reddy’s actions do not overcome the fact that it asked the FDA to approve and hopes to receive from the FDA, approval to market a product within the scope of the patent-in-suit. The court explicitly stated that “[a]llowing Reddy to avoid infringement based on its unconventional and unenforceable ‘guarantee’ when it is asking for and may receive FDA approval to market a product within the scope of the innovator’s patent, would be incompatible with the basic principles of patent law.”

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