Docket No. 2011-1561 -1562
LOURIE, DYK, WALLACH
August 24, 2012
Brief Summary: Obviousness-type double patenting analysis relates to “what [was] previously claimed…not what [was] previously disclosed” although disclosure may prohibit subsequently patenting a previously disclosed use. And it may be difficult to prove a “complicated compound” providing “many opportunities for modification” obvious.
Summary: Teva appealed DC holding that Lilly’s (as exclusive licensee from Princeton) U.S. Pat. No. 5,344,932 relating to the chemotherapeutic agent pemetrexed (an anti-folate) is not invalid for double-patenting over U.S. Pat. Nos. 5.028,608 (claiming the “‘608 Compound”) and 5,248,775 (claiming an intermediate) (also exclusively licensed from Princeton to Lilly). The ‘932 patent claims pemetrexed as part of a Markush group (claims 1, 2 and 7) and specifically (claim 3). The ‘608 Compound differs from pemetrexed by containing a five-membered thiophene ring instead of a six-membered benzene ring in its aryl region, a substitution that Teva argued would have been consistent with “conventional wisdom” in the field as known antifolates contained a phenyl. Teva also argued that “an ordinarily skilled chemist presented with the ’775 Intermediate immediately would have recognized pemetrexed as an obvious potential end product.” The DC rejected these arguments, “finding persuasive other evidence indicating that one of skill in the art would have pursued changes outside of the aryl region to improve  inhibition and would have avoided introducing a phenyl group into the ’608 Compound based on previous reports of toxicity with analogous antifolate structures” and “because, among many possible choices, a person of ordinary skill would not have made the structural changes necessary to derive pemetrexed” (regarding the ‘775 patent). The FC panel agreed, noting that “an analysis of obviousness-type double patenting ‘requires identifying some reason that would have led a chemist to modify the earlier compound to make the later compound with a reasonable expectation of success'” (Otsuka, FC 2012) and “a complicated compound such as the ’608 Compound provides many opportunities for modification, but the district court did not find that substituting a phenyl group into the aryl position was the one, among all the possibilities, that would have been successfully pursued.” The ‘775 arguments were also rejected because “the obviousness-type double patenting doctrine…rests on preventing a patentee from claiming an obvious variant of what it has previously claimed, not what it has previously disclosed” (citing In re Avery, CCPA 1975; Gen. Foods, FC 1992; contrasting In re Byck (CCPA 1931), Sun (FC 2010), Geneva Pharm. (FC 2003), and Pfizer, FC 2008 (“…in each of those cases, the claims held to be patentably indistinct had in common the same compound or composition—that is, each subsequently patented ‘use’ constituted a, or the, disclosed use for the previously claimed substance.”) The panel also noted that “pemetrexed and the ’775 Intermediate exhibit substantial structural differences”, “neither embodies or subsumes the other” and “pemetrexed can be made via any of several synthetic techniques, many of which do not involve the ’775 Intermediate.” The DC refusal to hear Lilly’s evidence of secondary considerations was concluded to be harmless. Thus, the DC judgment was affirmed.