Cubist Pharma v. Hospira (Fed. Cir. 2015)
An interesting aspect of this Hatch-Waxman decision involves the question of whether the PTO properly issued a certificate of correction.
Justification for a Certificate of Correction: The Patent Act authorizes the issuance of a certificate of correction when “a mistake in a patent, incurred through the fault of the USPTO, is clearly disclosed by the records of the Office” 35 U.S.C. § 254 or “a mistake of a clerical or typographical nature, or of minor character, which was not the fault of the USPTO, appears in a patent and a showing has been made that such mistake occurred in good faith.” 35 U.S.C. § 255.
In this case, the original patent filing included a structural diagram of the claimed daptomycin compound that was inaccurate because it misidentified a stereoisomer of asparagine. It was only after the patent issued that researchers discovered that the compound contained the D-isomer rather than the L-isomer. To be clear, when the patent issued, scientists thought that the compound actually had the L-isomer but then later learned that it had the D-isomer.
Seeing that mistake, the applicant petitioned the PTO for a certificate of correction to correct the error in the specification and the PTO agreed. Now, Hospira argues that the correction unduly broadens the scope of the claims and thus should be stricken.
Impact of Striking a Certificate of Correction: I’ll pause here to note that the Patent Act does not directly identify any remedy associated with improper issuance of a certificate of correction. Generally, the only result is that an improperly issued certificate will be stricken – and only after clear and convincing evidence showing the improper issuance. Following this line of cases, the defendant Hospira is asking for here is simply that the patent be returned to its original pre-amended state.
On appeal, however, the Federal Circuit sided with the USPTO and district court – holding that the amendment was proper.
[T]he [district] court characterized the PTO’s action as simply correcting an error in the diagram … without changing the scope of the patent. The court agreed with Cubist that the specification made clear that the patent claimed the daptomycin compound all along; the pre-correction version merely misidentified the stereoisomer of the asparagine amino acid found in that compound. . . .
Contrary to Hospira’s argument, the original structural diagram … did not establish that the patent was directed to a compound other than daptomycin. As this court has noted, a chemical structure is “simply a means of describing a compound; it is not the invention itself.” UNM v. Knight (Fed. Cir. 2003).
In light of the heavy burden on a party seeking to invalidate a certificate of correction, we uphold the district court’s conclusion that the certificate of correction did not alter the scope of the patent, but merely corrected an error as to the chemical structure of daptomycin.
As noted above, the statute provides for correction of “a mistake of a clerical or typographical nature, or of minor character.” Here, the correction was deemed to fit within the “minor character” prong of the test. The decision itself is quite fact specific, but it does highlight the general fact that the “error” being corrected need not be simply a typo.