IP Law Daily Validity of patent relating to opioid drug OPANA®ER and injunction against generic manufacturers affirmed
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Thursday, May 17, 2018

Validity of patent relating to opioid drug OPANA®ER and injunction against generic manufacturers affirmed

By Joseph Arshawsky, J.D.

The federal district court in New York City did not err when it found a patent for controlled release formulation of the painkiller opioid oxymorphone nonobvious and definite and issued a permanent injunction against generic manufacture of the brand drug OPANA®ER, the United States Court of Appeals for the Federal Circuit has ruled in a non-precedential decision. On obviousness, the prior art discouraged controlled release of opioids with low bioavailability. The specification provides adequate support for the dissolution or release rate limitations recited in the relevant claims. The claims that recite the multiple peaks limitations are not invalid for indefiniteness. Finally, the package inserts supported infringement (Endo Pharmaceuticals Inc. v. Teva Pharmaceuticals USA, Inc., May 16, 2018, Hughes, T.).

Endo Pharmaceuticals Inc. ("Endo"), holder of the approved new drug application for OPANA®ER, sued generic manufacturers who filed abbreviated new drug applications for generic versions of OPANA®ER, alleging infringement of U.S. Patent Nos. 8,309,122 B2 and 8,329,216 B2. These patents relate to a controlled release formulation of the painkiller opioid oxymorphone suitable for twelve-hour dosing and claimed to cover OPANA®ER. The district court found all asserted claims of the ’122 and ’216 patents not invalid, and all but two of the asserted claims infringed. Specifically, the court found that the asserted claims of the two patents are not invalid for obviousness; that the asserted claims with the dissolution limitations are not invalid for lack of written description; and that the asserted claims reciting the multiple peaks limitations are not invalid for indefiniteness. The district court also found infringement of all but two of the asserted claims, and then issued a permanent injunction. The Federal Circuit affirmed.

Obviousness. The generic manufacturers failed to carry their burden to show that the asserted claims would have been obvious because the prior art references "strongly discourage a controlled release formulation of opioids with low bioavailability, such as oxymorphone, and, more critically, do not suggest the dissolution and pharmacokinetic limitations recited in the asserted claims of the ’122 and ’216 patents." Tellingly, the generic manufacturers’ own expert maintained the view that active ingredients with poor bioavailability would not be good candidates for controlled release dose forms. "The district court did not clearly err in finding that the references taught away from the claimed invention." The Federal Circuit also rejected the argument that the district court erred in finding that no prior reference of record teaches the dissolution limitations. Nor do any of the prior art references disclose the claimed food effect limitations. "The district court therefore did not err by concluding that the asserted claims of the ’122 and ’216 patents are not invalid as obvious."

Adequate specification. The generic manufacturers next argued that the district court erred by concluding that the asserted claims that recite the dissolution limitations are not invalid for lack of written description in the specification. The Federal Circuit found that the specification provides adequate support for the dissolution or release rate limitations recited in the relevant claims. The specification clearly explains that an analgesically effective dosage could contain as low as about 5 mg to as high as about 80 mg of oxymorphone hydrochloride. "Accordingly, Endo is entitled to claim not just the narrower range based on a 20 mg dosage, but a broader range based on 5 mg to 80 mg dosage—and that is exactly what it did in the claims reciting the dissolution limitations." Nothing in Federal Circuit case law requires patent owners to test release rates for each dosage level before claiming such rates in the patents. The district court therefore did not err.

Indefiniteness. The generic manufacturers next argued that the asserted claims that recite multiple peak limitations are invalid for indefiniteness. The Federal Circuit disagreed and found that the specification sufficiently describes the meaning and scope of the multiple peaks limitations. Indeed, the court found the peaks to be readily ascertainable as plotted in Figure 5 of the ’216 patent, "based on a plain inspection." The generic manufacturers "merely fish for far more precision than ‘reasonable certainty’ requires under our precedent."

Infringement. The district court properly credited the testimony of Endo’s expert who relied on information on package inserts of the proposed generics in finding infringement, and accordingly the Federal Circuit affirmed.

Because Endo demonstrated irreparable harm, the court affirmed the issuance of a permanent injunction.

The case is Nos. 2015-2021, 2015-2022, 2015-2023, 2015-2024, 2015-2025, 2015-2026, 2015-2028, 2015-2031, 2015-2033, 2015-2034, 2015-2035, 2015-2041, 2015-2042, 2015-2046, 2015-2047, 2015-2049, 2015-2059, 2015-2060, 2016-1025, 2016-1060, 2016-1117, 2016-1118.

Attorneys: Martin Jay Black (Dechert LLP) for Endo Pharmaceuticals Inc. Charles E. Lipsey (Finnegan, Henderson, Farabow, Garrett & Dunner, LLP) for Grunenthal GmbH. Elizabeth Holland (Goodwin Procter LLP) for Teva Pharmaceuticals USA, Inc. John C. O’Quinn (Kirkland & Ellis LLP) for Actavis Inc. and Actavis South Atlantic LLC.

Companies: Endo Pharmaceuticals Inc.; Grunenthal GmbH; Teva Pharmaceuticals USA, Inc.; Actavis Inc.; Actavis South Atlantic LLC

MainStory: TopStory Patent FedCirNews

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