Purdue Pharma L.P. et al. v. Epic Pharma, LLC et al.

Purdue Pharma L.P. et al. v. Epic Pharma, LLC (Docket No. 2014-1294)

Purdue Pharma L.P. et al. v. Mylan Pharmaceuticals, Inc. et al. (Docket No. 2014-1296)
Purdue Pharma L.P. et al. v. Amneal Pharmaceuticals, LLC (Docket No. 2014-1306, -1307)
Grunenthal GmbH, Purdue Pharma L.P. et al. v. Teva Pharmaceuticals USA, Inc. (Docket No. 2014-1311, -1312, -1313, -1314)
February 1, 2016

Brief Summary: DC finding that Purdue’s low-ABUK patents are invalid as obvious affirmed. DC finding that Grunenthal’s ‘383 patent as anticipated also affirmed. DC dismisal of remaining actions as collaterally estopped affirmed.

Summary: Purdue appealed DC decision (appeals consolidated) that is “low-ABUK” patents (US 7,674,799 and 7,683,072) and US 8,114,383 patents invalid for obviousness. The low-ABUK patents relate to oxycodone salt with low levels of the impurity 14-hydroxycodeineone (“14-hydroxy”), a type of alpha/beta unsaturated ketone (“ABUK”). The prior art synthesis resulted in “high levels” of 14-hydroxy (1500 ppm). In 2004, the FDA mandated that oxycodone products must have less than 10 ppm. Rhodes Technology, a subsidiary of Purdue, modified step three in the prior art process and noticed the “8 alpha” diastereomer of the impurity 8,14-7,8-dihydrocodeineone (“8,14-dihydroxy”) that was being transformed into 14-hydroxy in that step. Lawsuits asserting infringement of some or all of these patenst were filed against Teva, Epic, Mylan and Amneal.

The low-ABUK patents are continuations of the “Chapman Application” (11/391,897) with claims directed to the modified process. The PTO previously rejected the claims as obvious in an interference with US 7,153,966 (“Casner”), and the FC affirmed that decision (FC 2009). The claims of the low-ABUK patents are to products and “explicitly recite 8 as the source of at least a portion of the minimal amounts of 14-hyrdoxy remaining in the oxycodone API.” The DC found the low-ABUK patents to be invalid as obvious, in part because “the discovery of 8a was not necessary to the claimed invention: a skilled artisan would recognize that hydrogenation could be used to remove the remaining 14-hydroxy, regardless of the source of the 14-hydroxy” which the secondary considerations could not overcome. Relying on Eibel Process (US 1923, regarding a machine that remedied the problem of wrinkled paper during high-speed printing by increasing the pitch of a wire in the machine (nonobvious “where an inventor discovers a non-obvious source of a problem and then applies a remedy”)), Purdue argued “the discovery of the source of 14-hydroxy was not obvious, so the solution of hydrogenating the oxycodone salt must also be nonobvious.” The FC panel disagreed, however, because “here, Purdue did not claim the remedy of the problem of remaining 14-hydroxy in the oxycodone API-performing a second hydrogenation step” but “[i]nstead…claimed the end product” and “identification of the source…had not effect on the structure or nature of the low-ABUK oxycodone product.” In addition, “[o]ne need not know that the 14-hydroxy was derived from 8 alpha as opposed to 8 beta to answer [the] question” (“wherein at least a portion of the 14-hydroxy[] is derived from 8 alpha”) of “whether it would be obvious…to sue hydrogenation to remove the excess 14-hydroxy”. The “derived from 8 alpha” limitation was determined by the DC, and the FC agreed, to be a process limitation correctly disregarded since “[i]n determining validity of a product-by-process claim, the focus is on the product and not the process of making it” (Greeliant, FC 2012), and “an old product is not patentable even if it is made by a new process”). Purdue’s secondary consideration arguments failed because “Rhodes was not successful in marketing it low-ABUK oxycodone API to any significant customer other than Purdue, which is its corporate affiliate”, “there was no pressing need for companies to create a low-ABUK product before the FDA’s mandate”, and recognition by others that Rhodes discovered 8 alpha “does not equal praise for the invention-the low-ABUK oxycodone API.”

The ‘383 patent relates to “extremely hard” tablets (breaking strength of 500 N force) that “form[] a gel upon dissolution in water (in order to prevent injecting).” The hardness comes from high molecular weight polyethylene oxide (“PEO”), originally developed by Grunenthal with Johnson & Johnson for its osmotically-controlled oral release delivery system (OROS). Purdue obtained a license to this technology and used in its Reformulated OxyContin® product. The DC found the ‘383 claims anticipated by WO 97/49384 (“McGinty”). Grunenthal argued that “because the only specifically mentioned drugs [in McGinty] are non-opioids, McGinty does not describe formulations that contain opioids such as oxycodone” but the FC agreed with the DC that the use of the terms “such as” and “and the like’…demonstrate that the application discloses a broader group of analgesics than just those listed” (this situation “invokes the canon of construction ejusdem generis-which provides that general terms are construed as referring to things of the same kind as those specifically mentioned”). In fn5, the opinion notes the DC did not err in rejecting Grunenthal’s argument that the reference does not disclose the “abuse potential” limitation since “the record clearly demonstrates that opioids have abuse potential”. Grunenthal also argued McGinty does not inherently disclose the breaking strength of at least 500N but the FC concluded the DC correctly credited expert testimony that, for example, “recreated the McGinty Application’s process fairly, accurately, and with no material variation”. Footnote 6 explains that “Grunenthal incorrectly characterizes the McGinty disclosures” by relying “on one isolated sentence to support its argument”. Grunenthal also argued that the DC “erred by using distinct sections of McGinty and reassembling them into an embodiment to find that all of the limtations were present” in the anticipation finding (Application of Arkley, CCPA 1972), which the FC panel found not to be “without merit” but ultimately agreed with the DC.

The FC panel also affirmed the DC dismissal of the remaining actions against Epic, Mylan, and Amneal as barred by collateral estoppel.

This entry was posted in Anticipation (35 USC 102), Collateral estoppel, Generics / ANDA, Obviousness. Bookmark the permalink.

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