Eli Lilly & Co. v. Teva Parenteral Meds. Inc.

Case Name: Eli Lilly & Co. v. Teva Parenteral Meds. Inc., CaseNo. 2011-1561, 689 F3d 1368 (Fed. Cir. August 24, 2012) (Circuit Judges Lourie, Dyk and Wallach presiding; Opinion by Lourie.) (Appeal from D. Del., Sleet, C.J.) 

Drug Product and Patent(s)-in-Suit: Alimta® (pemetrexed); U.S. Pat. No. 5,344,932 (“the ’932 patent”)

Nature of the Case and Issue(s) Presented: The issue here concerns whether the asserted claims of the ’932 patent were invalid for obviousness-type double patenting.  Appellee Eli Lilly & Co. (“Lilly”) manufactures an antifolate chemotherapy drug commercially sold as Alimta.  The drug is used primarily to combat mesothelioma and non-small cell lung cancer.  The ’932 patent was assigned to the Trustees of Princeton University, and exclusively licensed to Lilly.

Teva Parenteral Medicines, Inc., Barr Laboratories, Inc., and APP Pharmaceuticals, LLC (collectively, “Teva”) filed an ANDA seeking approval to manufacture and sell generic Alimta prior to the expiration of the ’932 patent on July 24, 2016.  The ANDAs each included a Paragraph IV certification resulting in Lilly’s suit against Teva asserting claims 1, 2, 3, and 7 of the ’932 patent.  At trial, Teva conceded infringement, but argued that the claims were invalid for obviousness-type double patenting over two claims in earlier issued patents that had expired.  The court found Teva’s obviousness-type double patenting argument lacked support, and enjoined approval of Teva’s ANDA until after the expiration of Lilly’s exclusive patent rights on the drug.  Teva filed a timely appeal; the Federal Circuit affirmed the district court’s decision. 

Why Lilly Prevailed:  The sole issue on appeal was whether the asserted claims of the ’923 patent were invalid for obviousness-type double patenting.  Teva’s argument was based entirely on two patents in the same family as the ’923 patent.  Both patents had expired before Lilly had filed suit.  U.S. Patent No. 5,028,608 (“the ’608 patent”) claimed an antifolate that differed from the chemical structure of pemetrexed only in its aryl region.  The compound claimed in the ’608 patent contained a five-member thiophene ring in place of the six member benzene ring found in pemetrexed.  U.S. Patent No. 5,248,775 (“the ‘775 patent”) disclosed a family of chemical intermediates that could be used to make a variety of antifolates, including pemetrexed, that contained a pyrrole[2,3-d]pyrimidine bicyclic core.  Among other compounds, the ’775 patent claimed a compound that is used as an intermediate in one method of synthesizing pemetrexed.

First, Teva argued that pemetrexed is not patentably distinct from the compound claimed in the ’608 patent.  The Federal Circuit took issue with Teva’s argument that a proper obviousness-type double patenting analysis involved analyzing only the differences between the claims at issue, so that any features held in common between the claims would be excluded from consideration.  The court noted that this was an overly myopic view of the analysis, and stated that rather than considering the differences in isolation, the claims had to be considered as a whole.  The court also found that Teva failed at trial to provide evidence of the existence of a reason that would have led a chemist to modify the compound claimed in the ’608 patent to make pemetrexed with a reasonable expectation of success.  Instead, the Federal Circuit found that Lilly had provided convincing evidence that the ways in which a person of ordinary skill in the art would modify the ’608 compound would not have resulted in pemetrexed.  The court noted that such findings of fact were entitled to considerable deference on appeal, and could not find any clear error with respect to the record.

Teva’s second argument was that pemetrexed was not patentably distinct from a compound claimed in the ’775 patent.  Rather than relying on structural similarities between the ’775 compound and pemetrexed, Teva argued that the specification of the ’775 patent disclosed the potential of synthesizing pemetrexed using the ‘775 compound.  The Federal Circuit held that Teva had improperly applied the obviousness-type double patenting analysis, because such an analysis should be based on a comparison between a patentee’s earlier and later claims, with the earlier patent’s written description considered only to the extent necessary to construe its claims.  Though Teva cited to two cases that appeared to be an exception to this general rule, the court said those cases were distinguishable.  In both of the cases that Teva cited, the court addressed situations where an earlier patent claimed a compound, disclosed the utility of that compound in the specification, and a later patent claimed a method of using that compound for a particular use described in the specification of the earlier patent.  In each of those cases, the claims held to be patentably indistinct had in common the same compound or composition.

Finally, the court addressed the district court’s failure to consider objective indicia of nonobviousness.  At trial, Lilly provided evidence that pemetrexed exhibited unexpected clinical properties and achieved considerable commercial success.  But the district court disregarded that evidence on the basis that secondary considerations were not relevant to the analysis of invalidity for obviousness-type double patenting.  The Federal Circuit noted that such a blanket statement was not accurate, and was the result of a misinterpretation of a footnote in the Geneva case.  Instead, the Federal Circuit held, when offered, such evidence should be considered.  The Federal Circuit, however, noted that the error was harmless, due to the fact that the court had properly rejected Teva’s obviousness-type double patenting argument on other grounds.