Fed. Cir. affirms PTAB IPR decision finding BTGs’s ZYTIGA® (abiratone) Orange Book ‘438 method of treatment patent invalid for obviousness

BTG Int. Ltd. and Janssen Biotech, Inc. et al. v. Amneal Pharmaceuticals LLC, et al.

Docket Nos. 2019-1147, -1148. -1323, -1324, -1325
May 14, 2019

Brief summary: PTAB IPR decision finding BTGs’s ZYTIGA® (abiratone) Orange Book ‘438 method of treatment patent invalid for obviousness affirmed.

Summary: This appeal relates to ANDAs filed regarding BTGs’s ZYTIGA® product (abiratone) filed by Amneal, Amerigen, Mylan, Teva, and Wockhardt. Amerigen, Mylan, and Wockhardt filed three IPRs (IPR2016-00286. -01332, and -01582), for which the USPTO issued final written decisions (FWDs) finding the Asserted Claims of BTG’s pre-AIA US 8,882,438 (the only patent listed on the FDA’s Orange Book for ZYTIGA) invalid for obviousness. The DC decision (Amneal, Teva) also found the ‘438 claims invalid for obviousness. This FC opinion affirmed the Wockhardt IPR and therefore dismissed the other appeals. Representative ‘438 claim 1 is directed to “[a] method for the treatment of a prostate cancer in a human being comprising administering to said human a therapeutically effective amound of abiratone acetate…and a therapeutically effective amount of prednisone.” The FC panel opinion explains that in Amerigen’s and Mylan’s IPR petitions “[t]he central issue before the PTAB was whether a person having ordinary skill in the art (‘PHOSITA’) would have known from the references that prednisone could be used a cancer ‘treatment’”, which the PTAB determined, under the then-governing broadest reasonable interpretation (‘BRI’) standard” to require “the eradication, removal, modification, management or control” of cancer accomplished “perhaps by an anti-cancer effect, or perhaps by some other mechanism.” And the PTAB, “under its construction,” concluded “the Asserted Claims would be obvious because of the use of ‘comprising’” (“[t]reatment by steroids can also refer to the other treatments that are ‘included’ in the construction”). Wockhart’s IPR Petition asserted obviousness over three prior art references, and the PTAB found obviousness over these references “for similar reasons” as in the Amerigen and Mylan FWDs. The FC panel first concluded that the PTAB’s construction of the “treatment” limitation was correct since, e.g., the ‘438 specification requires that “any definition of ‘treatment’ must encompass the full range of therapeutic agent’s effects disclosed” therein, “[p]rednisone is one such disclosed therapeutic agent”, and “[t]he specification states that a ‘therapeutic agent’ may be either ‘an anti-cancer agent or a steroid’” (“the use of ‘or’…suggests that a steroid is not necessarily the same thing as an anti-cancer agent…[i]f the patentee intended to limit ‘treating’ and ‘therapeutic agents’ to anti-cancer agents, the patentee neither would have identified steroids separately…nor described prednisone repeatedly in the specification as a steroid without mentioning any anti-cancer effect” (Housey, FC 2004)). The FC panel also explained that “[t]he prosecution history does not detract from, and if anything, supports the PTAB’s construction” as it “is consistent with the understanding that the claimed ‘treatment’ requires the use of abiraterone coincidingly with prednisone because the claims were not allowable otherwise” (Knowles, FC 2018)). Based on this claim construction, the FC panel found that substantial evidence supports the PTAB’s obviousness findings (e.g., “a reasonable expectation that prednisone could be used as a therapeutic agent in the treatment of prostate cancer”, “abiraterone and prednisone…were both together and individually considered promising prostate cancer treatments at the time”, “[t]he Asserted Claims…do not require a survival advantage” (Pfizer, FC 2007 (“[T]he expectation of success need only be reasonable, not absolute.”), “lack of enthusiasm by a few is not equivalent to skepticism or failure of others such that the combination would not have been obvious”, no convincing evidence regarding secondary considerations). The PTAB’s obviousness determination in the Wockhardt IPR was therefore affirmed and the other appeals dismissed as moot.

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

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