Fresenius-Kabi USA LLC v. Cubist Pharmaceuticals, Inc.

IPR2013-00223 (U.S. Pat. No. 6,852,689 B2)
Petition for IPR granted
May 14, 2016

Brief Summary: Petition for IPR regarding Cubicin’s ‘689 encompassing methods for administering daptomycin on obviousness grounds granted. Argument that Petition “relies on prior art previously presented to the PTO during prosecution” rejected.

Summary: Cubist’s ‘689 patent is directed to “[a] method for administering daptomycin, comprising the step of administering to a human patient in need thereof a therapeutically effective amount of daptomycin in a dose of at least 3 mg/kg of daptomycin at a dosage interval that minimizes skeletal muscle toxicity, wherein the daptomycin dose is repeatedly administered at a dosage interval of once every 48 hours to once weekly.” Fresenius petitioned for IPR on the basis that the ‘689 patent is invalid as obvious in view of Elli Lilly / Cubist’s U.S. Pat. No. 5,912,226 in view of “Rotschafer”, or in view of Rotschafer and “Woodworth”. The Board sided with Cubist on defining the person of ordinary skill in the art as one “familiar with methods for administering antibiotics, the relevant class of drugs for daptomycin”. Under the broadest reasonable construction (BRC) (In re Cuozzo, FC 2015), the Board concluded “at a dosage interval that minimizes skeletal muscle toxicity” (the only term construed) does not “require[] anything beyond administering daptomycin at the express dosage intervals recited in the claim” (“‘minimiz[ing] skeletal muscle toxicity’ would be understood as nothing more than the intended result or consequence of administering daptomycin at the specifically recited dosage interval”, “consistent with the Specification…Abstract…does not indicate that the minimization of skeletal muscle toxicity is due to any variable other than extending the dosage interval to once every 24 hours of more”). Cubist argued it should be construed as “at a dosage interval that reduces skeletal muscle toxicity in comparison to dosing more than once every 24 hours” and “is limiting because it…describes ‘an essential part of the invention’ and was relied upon during prosecution to distinguish the claimed invention from the prior art.” The Board was not persuaded, explaining that “none of the case law cited by Patent Owner…addresses the issue of essentiality or [PHE] where the claim term was defined further by additional language in the claim, particularly under” BRI. The Board also concluded the ‘226 patent discloses that daptomycin “can be administered ‘as a single daily dose or in multiple doses per day”, “may require administration over extended periods of time, such as for several days or two to four weeks”, and “[t]he amount…will depend on such factors as…the tolerance of the patient to the antibiotic”.

Rotschafer was found to teach 24-hour dosing of 6 mg/kg daptomycin and that “dosage adjustment appears necessary in patients with impaired renal function”. Woodworth was found to teach separation of daptomycin doses of 2, 3, 4 and 6 mg/kg by “at least 72 hours” were “well tolerated”. The Board concluded the prior art teaches at least 3 mg/kg (Iron Grip, FC 2004; In re Peterson, FC 2003 (overlap of ranges)). The higher claimed dosage of between 25 and 75 mg/kg were acknowledged to be outside the range of the ‘226 patent but the Board concluded it would have been obvious to increase the dosage amount “for more severe infections”. It also found the 48 hours or higher to have been disclosed by the prior art and that this “inherently meets the requirements of a dosage interval that minimizes skeletal muscle toxicity” (“Patent Owner has not identified any contrary evidence”). Cubist argued Fresenius had violated 37 CFR 42.104(b) by improperly relying on additional references that were not included in “Ground 2” but the Board was not persuaded (“Under the circumstances of this case, we do not find it improper to cited other prior art references as support for Petitioner’s assertions regarding the state of the art at the time of the claimed invention.”) Cubist also unsuccessfully argued the Petition should be denied “because it relies on prior art previously presented to the PTO during prosecution” (“[R]ejecting a petition under 35 USC 325(d) is discretionary. Here, we decline to exercise our discretion…particularly in light of the foregoing determination that Petition has established a reasonable likelihohod of prevailing on its patentability challenges.”) The Board also declined to grant the petition on the basis of the ‘226 patent and Rotschafer without Woodworth.

This entry was posted in Inter Parties Review (IPR), IPR, Obviousness. Bookmark the permalink.

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