Here's something you don't see every day: an ANDA filer suing a brand-name drug manufacturer for patent infringement.
In late 2007/early 2008, AstraZeneca ("AZ") filed suit against nine different ANDA filers, including Teva, seeking approval to market generic versions of Crestor (rosuvastatin). The cases were consolidated in multidistrict litigation in the District of Delaware (No. 08-md-01949), and proceeding through discovery when, in October 2008, Teva sued AZ, alleging that Crestor infringes Teva's U.S. Patent No. RE39,502. Claim 1 of the '502 patent reads: "A stabilized pharmaceutical composition for the treatment of dyslipidemia, comprising [rosuvastatin] and a stabilizing effective amount of at least one amido-group containing polymeric compound . . . ."
AZ filed a motion for summary judgment of patent invalidity due to prior invention pursuant to 35 USC 102(g)(2), which states that a person shall be entitled to a patent unless "before such person's invention thereof, the invention was made in this country by another inventor who had not abandoned, suppressed, or concealed it." AZ argued that it made a batch of Crestor tablets meeting each limitation of the asserted '502 patent claims prior to December 1, 1999, the earliest date by which Teva claimed to have conceived of and reduced to practice the claimed formulation.
Teva did not dispute that AZ made a batch of Crestor tablets before December 1, 1999. Rather, Teva argued that even if AZ created the exact infringing commercial formulation in mid-1999, AZ still could not prove conception or reduction to practice of the invention claimed by Teva's '502 patent by that date because there was no evidence that AZ appreciated that crospovidone, the amido-group containing polymeric compound included in Crestor, contributes to the stability of the formulation. According to Teva, because AZ never appreciated that crospovidone contributes to the stability of its Crestor product formulations, it cannot have "created an embodiment that literally met all of the limitations of Teva's claims."
Last month, the district court granted AZ's motion for summary judgment. The district court explained in its opinion (pdf) that to establish priority of invention, there must be evidence not only that the inventor "actually first made the invention" but also that he "understood his creation to have the features that comprise the inventive subject matter." But, according to the court,
the inventor need not establish that he recognized the invention in the same terms as those recited in the claims as the invention is not the language of the claims but the subject matter thereby defined. Rather, the inventor must establish that he recognized and appreciated a compound corresponding to the compound defined by the claims.
The court continued:
Applying this principle--that the discovery of a previously unappreciated property of a prior art composition, or of a scientific explanation for the prior art's functioning, does not render the old composition patentably new to the discoverer--the Federal Circuit has held invalid for anticipation numerous patents claiming what amount to newly discovered properties of prior art compositions, where the missing characteristic was necessarily present, or inherent, in the prior art, even though there was no recognition of the missing characteristic in the prior art.
According to the court, it was undisputed that AZ recognized that its Crestor formulations were stable and sufficiently finalized to proceed commercially.