In re Rosuvastatin Calcium Patent Litigation

By Jason Rantanen

In re Rosuvastatin Calcium Patent Litigation (Fed. Cir. 2012) Download 10-1460
Panel: Newman (author), Plager (concurring), Mayer (dissenting)

This appeal arises in the context of the patent war over rosuvastatin, a multi-billion dollar pharmaceutical product sold by Astrazeneca under the name CRESTOR.  At issue on appeal was the central component of Astrazeneca's protection for rosuvastatin: the composition patent (RE 37,314).  The short version is that Astrazeneca has won for the time being: the Federal Circuit ruled in favor of Astrazeneca on all issues.  However, the composition patent is set to expire in 2016, and Astrazeneca previously failed in its bid to enforce its later-expiring method-of-use patents against the generic manufacturers.

Reissue: The '314 patent is a reissue of Patent No. 5,260,440, whose specification describes rosuvastatin as the preferred embodiment.  During the prosecution of the '440 patent, the prosecuting attorney became aware of two potentially relevant prior art references through an internal search report.  The prosecuting attorney did not disclose the references to the PTO, however (no IDS was filed at all), and when the '440 patent issued the patent contained a broad genus claim that overlapped with one of the references.

Several years after the patent issued, it was discovered during licensing negotiations that no IDS had been filed during prosecution of the '440 application and that the examiner had not cited the two references.  The patent holder initiated reissue proceedings, which ultimately resulted in the patent being limited to the specific compound rosuvastatin and its salts. 

In addition to raising an inequitable conduct argument (which the court rejected on lack of intent grounds), the defendants argued that reissue was improper because there was no error and because there was deceptive intent.  While the AIA removed the statutory requirement that the error providing the basis of the reissue occur "without any deceptive intention," this opinion is significant for its broad interpretation of what constitutes "error" in the context of a reissue, an issue that will have ongoing importance:

Precedent establishes that for reissue purposes “error is established where there is no evidence that the appellant intentionally omitted or abandoned the claimed subject matter.” Ball Corp. v. United States, 729 F.2d 1429, 1435–36 (Fed. Cir. 1984). Here, the district court found as fact that Shionogi erred by failing to file an IDS citing the Sandoz and Bayer references, and by omitting a specific claim to the preferred species. However, the court found no evidence of a deliberate choice to omit or abandon the rosuvastatin species, which was described in the specification as the most effective product. 

Slip Op. at 21.  The court further noted that past precedent supports the practice of narrowing claims through reissue. 

On deceptive intent (which will still be relevant for any reissue proceedings initiated prior to September 16, 2012), the majority held that deceptive intent for reissue purposes applies the same standard as deceptive intent in the inequitable conduct context.

Judge Mayer, writing in dissent, disagreed that reissue was proper.  "A patentee cannot establish correctible "error" under section 251 simply by demonstrating that his original patent contains a defect…Instead, reissue is warranted only where a patentee "supplies…facts indicating how…ignorance," accident, or mistake caused an error in his claims." Dissent at 6-7.  He also expressed concern about the consequences of the majority's broad reading of "error":

The claims of a validly-issued patent serve an important notice function, alerting the public of the metes and bounds of an inventor’s discovery. [] This public notice function will be subverted if the “error” requirement is read out of the reissue statute and patentees are given free reign to rewrite their claims whenever they find it expedient to do so. []

Dissent at 13 (citations omitted).

ANDA Filing by a US Subsidiary "On Behalf Of": One of the generic manufacturers, Apotex, raised a creative theory of noninfringement.  Apotex Corp. is a United States affiliate of the Canadian Company Apotex Inc.  The Abbreviated New Drug Application that triggered the infringement suit was signed and filed by the US affiliate on behalf of the Canadian company.  Given this arrangement, Apotex raised a number of arguments supporting the theory that the US affiliate did not "submit" the ANDA within the meaning of the infringement statute, 35 U.S.C. §271(e)(2)(A), and thus it could not infringe the patent.  (The Canadian company was not a party to the suit).

Judge Newman, writing for the majority, affirmed the district court's rejection of this theory without substantial analysis.  Slip Op. at 31.  Judge Plager's concurrence, however, provides a detailed analysis of why Apotex's arguments fail to preclude liability for infringement.  One key bit: 

More directly, however, in this case Apotex U.S. clearly intends to engage in, and presumably submitted the ANDA for the purpose of, selling the approved drug in the United States. The statute speaks not only in terms of engaging in commercial manufacture, but, disjunctively, in terms of engaging in the drug’s “use or sale.” As an acknowledged sales agent for the primary applicant, Apotex U.S. can be treated as simply having “submit[ted]” an application for an ANDA for the purpose of “engag[ing] in the commercial . . . sale of [the] drug . . . claimed in a patent.”  

Concurrence at 6.

Nonobviousness and No Inequitable Conduct: The Federal Circuit also affirmed the district court's ruling that the '314 patent was nonobvious and that it was not unenforceable due to inequitable conduct.  On obviousness, the defendants used a "lead compound" theory, arguing that a prior art patent publication suggested that a particular compound ("Compound 1b") would be a good "lead compound" for further research and that there was a motivation to modify that compound to arrive at the claimed invention.  The Federal Circuit affirmed the district court's conclusion that the defendants failed to demonstrate that there was a motivation for selecting Compound 1b as a lead compound or making the relevant modification.  It further agreed that the idea that it might be "obvious to try" making and testing this compound was negated by evidence of skepticism in the field. 

On inequitable conduct, the Federal Circuit affirmed the district court's finding of lack of deceptive intent.  It declined to disturb the court's finding that the withheld references were material.

9 thoughts on “In re Rosuvastatin Calcium Patent Litigation

  1. 8

    The public is protected by intervening rights. The only purpose of denying the reissue under the circumstances would be to punish the patent owner. But without a finding of inequitable conduct, there would be no reason to do so.

  2. 7

    Paul, I agree. The public is protected by intervening rights. The only purpose of denying the reissue under the circumstances would be to punish the patent owner. But without a finding of inequitable conduct, there would be no reason to do so.

  3. 6

    Agreed. Simple failure to disclose a reference is not enough to prove inequitable conduct. Had Newman strayed from this line whatsoever, the case would’ve been fraught with peril for Therasense.

  4. 4

    The dissents views on narrowing reissues is of concern. One wonders if that judge is aware of the fact that reexaminations are publicly open files, that both the recapture doctrine and intervening rights statutes apply, and the impact of the CAFC J. Newman decision of Bloom Engineering Co. v. North American Mfg. Co., CAFC 11/21/97. It was on a reexamination, but applies to a narrowing reissue. The opinion discussion is copied below.

    “Sections 307 and 252 shield those who deem an adversely held patent to be invalid; if the patentee later cures the infirmity by reissue or reexamination, the making of substantive changes in the claims is treated as an irrebuttable presumption that the original claims were materially flawed.* [!] Thus the statute relieves those who may have infringed the original claims from liability during the period before the claims are validated.”

    Thus a reissue that results in narrower claims substantially reduces the period for potential damages recovery, even after notice or marking, unless at least one original claim is both infringed and substantially un-amended.

  5. 1

    A Waxman-Hatch case with Judge Newman finding for the ethical pharmaceutical company. How … unsurprising. Having been in this space since 1984 when the Act was passed, I have not seen her side with the generic manufacturing company on any argument in any case.

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