Cephalon Inc. v. Mylan Pharma. Inc.

After construing certain disputed claim terms, the court found the asserted claims infringed and not invalid.

Fall 2013

GENERICally Speaking

Case Name: Cephalon Inc. v. Mylan Pharma. Inc., Civ. No. 11–164–SLR (SLR), 2013 U.S. Dist. LEXIS 101848 (D. Del. July 22, 2013) (Robinson, J.)

Drug Product and Patent(s)-in-Suit: Fentora® (fentanyl buccal tablets); U.S. Patent Nos. 6,200,604 (“the ‘604 patent”), 6,974,590 (“the ‘590 patent”), 8,092,832 (“the ‘832 patent”), and 8,119,158 (“the ‘158 patent”)

Nature of the Case and Issue(s) Presented: The issues addressed here were the construction of two disputed claim terms, and whether the claims of the asserted patents were infringed and valid. The patents-in-suit claim oral effervescent pharmaceutical dosage forms of Fentora, which is used to treat breakthrough pain in cancer patients.

Prior to trial, Cephalon agreed not to assert infringement of the ‘832 and ‘833 patents, and Mylan agreed not to challenge their validity. Mylan also dropped its invalidity counterclaims relating to the ‘604 and ‘590 patents and did not contest infringement of the ‘832 patent. This narrowed the issues at trial to infringement of the ‘604 patent, infringement of the ‘590 patent, the validity of the ‘832 patent, and the infringement and validity of the ‘158 patent. A bench trial was held from March 11, 2013 to March 15, 2013 to resolve the remaining issues. The court found that the asserted claims of the ‘604, ‘590, and ‘158 patents were infringed, and that the ‘832 and ‘158 patents were not invalid.

Why Cephalon Prevailed: The court first construed two disputed claim terms: “providing a solid oral dosage form” and “pH adjusting substance is not a component of said effervescent material.” Cephalon argued that “providing a solid oral dosage form” should be given its plain and ordinary meaning. Mylan’s proposed construction was “supplying a solid oral dosage form to a patient,” which Mylan argued would exclude a patient from applying the dosage form to herself. The court agreed with Cephalon because nothing in the claims, specification, or the prosecution history evidenced an intent to exclude a patient from administering the dosage to herself. Moreover, because the claim term did not need to be construed, Mylan’s citation to extrinsic evidence was unavailing.

Cephalon also argued that “pH adjusting substance is not a component of said effervescent material” should be afforded its plain and ordinary meaning, or, in the alternative, the term should be construed to mean that “the pH adjusting substance is in addition to the components of said effervescent agent.” Mylan posited the following construction: “the pH adjusting substance is not one of the components used to generate effervescence.” Mylan’s construction precluded the pH adjusting substance from participating at all in any effervescent reaction. Again, the court agreed with Cephalon, finding that while the effervescent agent and pH adjusting substance had to be separate and distinct components, there was no further limitation that the pH-adjusting substance could not be involved in generating additional effervescence.

The court next addressed whether Mylan’s proposed generic product infringed the asserted claims of the ‘604 and ‘590 patents. Mylan argued that its ANDA products did not meet the claim limitation requiring “at least one [salival activated] effervescent agent in an amount sufficient to increase absorption.” Cephalon argued that the sodium bicarbonate and citric acid in Mylan’s ANDA product were effervescent agents under the court’s claim construction because they emitted carbon dioxide gas by means of an effervescent reaction. As such, the sodium bicarbonate and citric acid were effervescent agents separate from the pH-adjusting substance, sodium carbonate, in the ANDA drug. Mylan further argued that the claim limitation was not met because some portion of the sodium carbonate could effervesce. The court, instead, found that because there were separate effervescent agents (citric acid and sodium bicarbonate) and a pH adjusting agent (sodium carbonate) the claim limitation was met by the ANDA product.

The court next addressed the issue of infringement concerning the ‘158 patent. The limitation at issue involved “wherein said pH adjusting substance is not a component of said effervescent material.” Mylan’s argument hinged on its proposed construction that the pH adjusting agent have no effervescent property. Such a construction would have foreclosed the use of sodium carbonate as the pH adjusting agent because it also had some effervescent properties. But the court’s claim construction—which required that the pH adjusting agent and the effervescent agent be separate agents—rendered Mylan’s argument moot. Its construction did not foreclose the possibility that the pH adjusting agent could also effervesce, so long as there was a separate effervescent agent. Thus, the court found that Mylan’s ANDA product would infringe the ‘158 patent.

The court next addressed the issue of validity concerning the ‘832 and ‘158 patents. Mylan first argued that those patents were anticipated by U.S. Patent No. 6,200,604 (“the ’604 patent”), which disclosed using an effervescent agent comprising a food acid and a bicarbonate, such as citric acid and sodium bicarbonate. Cephalon countered that the ‘604 patent did not disclose limitations that were found in the asserted patents, such as the amounts of fentanyl and the combination of filler mannitol and the disintegrant SSG. The court agreed and held that the ’604 was not an anticipatory reference.

Next, Mylan argued that the ‘832 and ‘158 patents were obvious in view of the ‘604 patent in combination with an Actiq® (a commercial fentanyl product) brochure and the handbook. Cephalon responded that combining ranges of fentanyl with effervescence, mannitol and SSG, were the novel aspects of its patents. It did not dispute that the disclosures from the ‘604 patent, the brochure, and the handbook disclosed all of the claimed limitations. Rather, Cephalon argued that Mylan failed to carry its burden of showing that a person having ordinary skill in the art would have been motivated to abandon the use of lactose and crospovidone in favor of mannitol and SSG in oral transmucosal fentanyl tablets. Cephalon also pointed to various secondary considerations as objective evidence of non-obviousness. The court took issue with Mylan’s analysis, finding that its expert had engaged in impermissible hindsight in his obvious analysis. It also noted that the mere fact that a component was known in the art at the time of invention was not sufficient to establish a motivation to substitute it for a more commonly-used component. Mylan therefore failed to carry its burden that the use of SSG alone or in combination with mannitol was obvious in light of the cited prior art references. This finding was further bolstered by Cephalon’s evidence of secondary considerations of non-obviousness, including evidence showing unexpected results.

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