In re Rosuvastatin Calcium Patent Litigation (Fed. Cir. 2012)

Late last year, in AstraZeneca v. Aurobindo (In re Rosuvastatin Calcium Patent Litigation), the Federal Circuit affirmed that a reissue patent covering the active ingredient of Crestor® was valid, enforceable, and infringed by all parties.  In so doing, the Court discussed what it meant to be the submitter of an ANDA for the purposes of infringement within the Hatch Waxman scheme of 35 U.S.C. § 271(e)(2).  In addition, the Court provided a lengthy explanation about what it means to have a patent deemed wholly or partially inoperative or invalid "through error without any deceptive intention," such that it is entitled to take advantage of the reissue statute of 35 U.S.C. § 251.  In this case, the majority reviewed the background, prosecution history and District Court's analysis and determined that the lower court correctly found that Patent Office correctly allowed the patent holders to seek reissue of the patent at issue.  However, Judge Mayer in dissent disagreed, because in his view the prosecutors' actions were intentional, and therefore could not be considered error.  Moreover, the dissent noted that the patent holder did not present any evidence that it acted without deceptive intent, which he noted is required to seek reissue.  As a result, he would have found the patent invalid for improper reissue.  The Federal Circuit also affirmed the District Court's determinations regarding obviousness and lack of intent necessary to find inequitable conduct.

CrestorThe drug at issue in this case was rosuvastatin, the calcium salt of which is sold as the active ingredient of Crestor®.  The compound was developed at Shionogi Seiyaku Kabushiki Kaisha ("Shionogi") in 1991, when its scientists were looking for a statin with reduced side effects as compared to the known statins at that time.  The sale and use of this drug was approved by the FDA on August 12, 2003.  The drug was so successful that several generic producers filed abbreviated new drug applications related to it.  The resulting infringement suits against Aurobindo Pharma Ltd, Mylan Pharmaceuticals, Inc., Apotex Corp. (USA), Cobalt Pharmaceuticals Inc. and Cobalt Laboratories Inc., Sun Pharmaceuticals Industries, Ltd., Teva Pharmaceuticals USA, Inc., Par Pharmaceuticals, Inc., and Sandoz, Inc. were consolidated in the U.S. District Court for the District of Delaware.  The lower court ruled that U.S. Patent No. RE37,314 ("the '314 patent") was not invalid as obvious over the prior art, not unenforceable due to a failure to file material references before the patent issued, properly reissued despite awareness of these material references at the time, and infringed by all parties.  All defendants conceded infringement except a Canadian generic manufacturer's U.S. subsidiary that alleged it only signed the ANDA application but also intended to market the drug in the U.S.  The defendants' appealed, and the Federal Circuit affirmed on all grounds, with a dissent from Judge Mayer, who would have invalidated the patent due to improper reissue.


Only one defendant, Apotex U.S., challenged infringement because it alleged that it was not the "submitter" of the ANDA in question.  The patent statute provides that submitting an ANDA is an act of infringement pursuant to 35 U.S.C. 271(e)(2)(A):

(2) It shall be an act of infringement to submit—
    (A) an application under section 505(j) of the Federal Food, Drug, and Cosmetic Act or described in section 505(b)(2) of such Act for a drug claimed in a patent or the use of which is claimed in a patent . . . if the purpose of such submission is to obtain approval under such Act to engage in the commercial manufacture, use, or sale of a drug, veterinary biological product, or biological product claimed in a patent or the use of which is claimed in a patent before the expiration of such patent.

Apotex U.S. presented several arguments in the District Court as to why it was not the "submitter" for the purposes of this statute.  Principally, Apotex U.S. asserted that it only signed and filed the ANDA as the agent for Apotex Canada, and therefore the interests of Apotex Canada would be unfairly affected because it was not subject to personal jurisdiction in Delaware.  The District Court deemed this "due process violation" argument unpersuasive because the Apotex Canada's rights were being represented by its agent and subsidiary, Apotex U.S.  Moreover, Apotex U.S. not only signed and filed the ANDA, but it participated in the ANDA's preparation and represented that it would be selling the product in this country.  The District Court determined that the definition of a "submitter" for the purposes of this statute includes a "subsidiary of a foreign ANDA applicant, which signs an ANDA as the agent . . . and which intends to benefit directly if the ANDA is approved."  The Federal Circuit did not find any error with this holding.

Apotex #1Apotex U.S. made additional arguments as to why it was not the ANDA submitter, all of which the District Court found unpersuasive.  For example, Apotex U.S. argued that Apotex Canada made the Paragraph IV certification, and that it was this certification that was the infringing act under § 271(e)(2).  However, as can be seen from the express language of the statute, as reproduced above, there is no mention of patent certification, much less an indication that it is the patent certification that gives rise to infringement liability.  Apotex U.S. also argued that § 271(e)(2) mentions 21 U.S.C. § 355(j) (as section 505(j) of the Federal Food, Drug, and Cosmetic Act), and therefore incorporates all of F.D.C.A act's requirements to establish infringement liability.  In addition, Apotex U.S. asserted that § 271(e)(2) makes no mention of active involvement, or parent-subsidiary relationships, and therefore these factors are irrelevant to the submitter issue.  It is of interest to note that, in order to avoid infringement liability, Apotex U.S. both requested that § 271(e)(2) be read literally, and asserted that the Act must incorporate requirements not expressly stated in the statute.  Nevertheless, the Federal Circuit concluded that the District Court did not err in finding all of these arguments unpersuasive.

The Federal Circuit's opinion provides very little (if any) reasoning why the District Court did not err in holding Apotex U.S. a properly named defendant in this case.  Instead, Judge Plager provided a concurrence to clarify his understanding as to why Apotex U.S. should be treated as the ANDA submitter.  § 271(e) has at least two requirements, according to Judge Plager:  (1) submission of an application (2) to obtain approval to engage in the commercial manufacture, use, or sale of a drug claimed in a patent.  First, it was noted that the statute was clearly not meant to apply to an individual, such as an attorney, who prepares and submits an application for the real party in interest.  The important inquiry, however, is whether the statute is meant to apply to an agent that has a financial interest in the manufacture and distribution of the drug.  Judge Plager pointed out that it was logical that such an agent should fall within the scope of the statue.  Nevertheless, in this case, Apotex U.S. had more than just a financial interest; it was going to be engaging in the commercial manufacture.  Therefore, under the "financial interest" standard, and certainly under the "active involvement in commercial manufacture" standard, Judge Plager believed that the District Court did not err in finding Apotex U.S. liable for infringement.


All of the defendants argued that the '314 patent was improperly reissued because there was allegedly (1) no error and (2) deceptive intent.  The reissue statue states that a patent holder can seek reissue of a patent when the patent is deemed inoperative or invalid "through error without any deceptive intention."  35 U.S.C. § 251.  This analysis is very fact intensive, and in fact, the majority used this fact in its reasoning to affirm the lower court's determination (because there were insufficient facts to overturn the decision).  Therefore, at least a brief review of the facts is necessary.

As explained by the Court's opinion, when Shionogi scientists obtained favorable results with certain modified pyrimidine compounds, including rosuvastatin, an employee in the patent department, Ms. Kitamura, obtained prior art search reports related to these products.  Included in these searches was a Sandoz European application, which included a compound that differed from rosuvastatin by one side chain constituent, and a Bayer Japanese application that described a class of statins to which rosuvastatin belonged, although without specifically identifying rosuvastatin.  Based on these results, Ms. Kitamura prepared and filed a Japanese patent application, to which the U.S. patent at issue claimed priority.  Ms. Kitamura left Shionogi about six weeks after the U.S. application was filed.  Mr. Shibata assumed responsibility for this application family and subsequently received an EPO search report that identified the Sandoz application as relevant art.  Mr. Shibata asked the scientists to compare the Shionogi compounds with those identified in the Sandoz and Bayer applications.  However, no IDS was filed before U.S. Patent No. 5,260,440 ("the '440 patent") issued (the 314 patent was a reissue of the '440 patent).  Also of note, the '440 patent did not contain a specific claim directed solely to rosuvastatin.  Only after AstraZeneca and Shionogi began license negotiations were these oversights discovered, and Shionogi shortly thereafter filed a reissue application.  Because the examiner rejected the generic claims in view of the Bayer reference, the claims were limited to rosuvastatin and its salts.  The reissue granted as the '314 patent.

With regard to whether there was error in the original patent, the Defendants asserted that deliberate prosecution decisions can never be corrected through reissue.  As such, because Shionogi deliberately presented only generic claims and allegedly deliberately presented claims that overlap with the Sandoz reference, the reissue was improper.  The case of In re Serenkin, 479 F.3d 1359 (Fed. Cir. 2007), was cited for this proposition.  However, this case involved an attorney that sought to add eight sheets of drawings to a pending PCT application, and in so doing, agreed to give up its priority date and settle for a filing date of the date on which the drawings were added.  After the patent holder attempted to "correct" the priority date through reissue back to that originally claimed, the Serenkin court pointed out that it was impermissible to undo the consequence of a conscious decision to give up a priority claim.  Important in that determination was that the attorney took action with the knowledge of what the consequences would be.  The Court's decision in the present case pointed out that, in some sense, all prosecution decisions are deliberate.  However, the purpose of the reissue statute was to fix such errors, provided there was no evidence that the claimed subjected matter was intentionally omitted or abandoned.  In other words, the important consideration for whether there was "error" is whether the correction sought encompasses "inadvertence, accidents, [or] mistakes."

The issue of deceptive intent can be intertwined with the issue of whether there was an error in the first place, but the Defendants also asserted that the Shionogi patent department intentionally withheld the prior art reference in order to obtain claims that overlapped the Sandoz reference.  They argued that the "deceptive intent" standard in the reissue statute requires less rigorous proof than that for establishing inequitable conduct.  However, the Federal Circuit could find no sound basis for such a distinction.  Ultimately, the Court relied on the lower court assessment of the live testimony of the "purported culprits," which found no evidence of deceptive intent that would have made the reissue improper.  Because it could find no error with this ruling, the majority affirmed.

A few of the issues raised by dissent are worth mentioning.  First, Judge Mayer took issue with the fact that "[n]ot a single inventor or patent prosecutor testified that he or she unknowingly or inadvertently introduced the overlap between Sandoz and claim 1."  However, the dissent doesn't comment on what the burden of proof or the burden of persuasion was in this case.  The Patent Office had already reissued the patent in question, and so it should have been entitled to the presumption of validity, which requires clear and convincing evidence to overcome.  The dissent appears to suggest, instead, that the burden was on the reissue patent holder to defend the reissued patent.  Unfortunately, most of the cases cited by the dissent were appeals from parties seeking reissues from the Patent Office.  In such cases, the procedural posture was different, because in such cases, it was the patent holder's burden to establish that it was entitled to a reissue.  When the proper burdens are considered, along with the fact that the District Court was able to weigh the live testimony of the witnesses, it would appear that the majority was correct in affirming the decision.

In addition, the dissent acknowledges that reissue is only proper if the error results from inadvertence, accident, or mistake.  However, Judge Mayer states on a couple of occasions that Shionogi "made an error in judgment," presumably suggesting that judgment errors could never be inadvertent, accidental, or mistaken.  To the contrary, all reissue errors can ultimately be considered errors in judgment, much like the majority noted with the Serenkin case that all prosecution decisions are ultimately deliberate.  If "lack of error in judgment" were the standard, it is unlikely that anyone would be entitled to seek a reissue patent.

Finally, the dissent notes that "[e]quity dictates that a patentee exercises due diligence in seeking to rectify a defect in his patent."  However, the dissent starts this "due diligence" clock from the date that Shionogi became aware of the Sandoz reference.  Instead, as the majority points out, Shionogi did act diligently, filing the reissue application almost immediately after the error was discovered.  If it were any differently, then the rest of the analysis regarding error and deceptive intent would have been unnecessary.  In fact, part of the error that entitled the patent holder to seek reissue was not appreciating that the claims as filed and issued would cover Sandoz.  The same error cannot be used to be justify reissue on one hand, and deny it for lack of diligence on the other.

In re Rosuvastatin Calcium Patent Litigation (Fed. Cir. 2012)
Panel: Circuit Judges Newman, Mayer, and Plager
Opinion of the court by Circuit Judge Newman; concurring opinion by Circuit Judge Plager; dissenting opinion by Circuit Judge Mayer



DISCLAIMER: Because of the generality of this update, the information provided herein may not be applicable in all situations and should not be acted upon without specific legal advice based on particular situations.

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