IN RE ROSUVASTATIN CALCIUM PATENT LITIGATION (Astrazeneca UK Limited, et al. v. Aurobindo Pharma Limited et al.)

Docket No. 2010-1460, etc.
December 14, 2012

Brief Summary: Successful rebuttal of obvious-to-try argument; inequitable conduct requires “clear and convincing evidence did not show that [applicant] made a deliberate decision to withhold [material] references from the PTO” (intent).

Summary: Aurobindo et al. appealed DC finding that Astrazeneca’s U.S. Pat. No. (Reissue) 37,314 relating to the statin drug Crestor (calcium salt of rosuvastatin) was not invalid for obviousness or unenforceable for inequitable conduct. Aurobindo et al. argued that “compound 1b” of EP 0367895 (Sandoz) would have been a good lead compound and that modifying the C2 position (-CH3 to –SO2CH3) would have been obvious (increase hydrophilicity, C2 known not to be critical to statin activity). The DC disagreed, finding the “obvious to try” arguments “negated by the general skepticism concerning pyrimidine-based statins, the fact that other pharmaceutical companies had abandoned this general structure, and the evidence that the prior art taught a preference not for hydrophilic substituents but for lipophilic substituents at the C2 position” (citing In re O’Farrell (FC 1988) (not obvious to try where “prior art gave only general guidance as to the particular form of the claimed invention or how to achieve it”) and Takeda (FC 2007) (“necessary to identify some reason that would have led a chemist to modify a known compound in a particular manner”)). Aurobindo et al. also argued that the patent was unenforceable for inequitable conduct because three prior art documents were not cited with deceptive intent (1) the initial Japanese (JP) prosecuting agent testimony that she possessed one of the references (listed on an EPO search report) and knew of her duty to disclose it to the USPTO; 2) an internal memo stating that “[d]evelopment information on S-4522 [rosuvastatin] must not be leaked to the outside because it is included in the text of the published unexamined Bayer patent application…”; and, 3) a subsequent JP prosecuting agent also knew of the references and did not disclose the same to the USPTO). The DC found those actions to be “suggestive of malfeasance…no more than a string of mishaps, mistakes, misapprehensions and misjudgments on the part of inexperienced and overworked individuals” but not intent to deceive (not “the single most reasonable inference to be drawn from these circumstances is deceptive intent” (Star Scientific (FC 2008) and Kingsdown (FC 1988)). The FC panel agreed (“clear and convincing evidence did not show that [the JP prosecuting agents] made a deliberate decision to withhold references from the PTO” (Therasense (FC 2011)). Improper resissue under 35 USC § 251 (1999 version; “without any deceptive intention” removed from 2011 amendment) was also argued (no error to correct, deceptive intent). However, the courts agreed there was no intention to omit specifically claiming the rosuvastatin species and no deceptive intent regarding the uncited references (Judge Mayer’s dissent disagreed (no “error” resulting from inadvertence, accident, or mistake)). In addition, Apotex US (one of the defendants) argued that it is not the infringing party as Apotex Canada filed the ANDA, but the neither the DC nor the FC panel was persuaded. Thus, the FC panel affirmed the DC decision.

This entry was posted in Generics / ANDA, Inequitable Conduct, Obviousness. Bookmark the permalink.

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