ENCANTA PHARMACEUTICALS, INC. v. PFIZER INC.
Before Lourie, Bryson, and Chen. Appeal from the United States District Court for the District of Massachusetts.
Summary: A patentee could not argue that its provisional application provided written description support for its issued claims by arguing that the provisional contained an obvious typographical error.
Enanta Pharmaceuticals sued Pfizer, alleging patent infringement. Enanta’s provisional disclosed a compound with an alkyl group containing between two and twelve carbon atoms. Pfizer later publicly disclosed a compound with a one-carbon alkyl group. Subsequently, Enanta filed a non-provisional application, which led to the asserted patent, whose claims encompassed one-carbon alkyl groups. Pfizer moved for summary judgment of invalidity, asserting that the patent could not claim priority from the provisional and was thus anticipated. Enanta argued that its provisional contained an obvious typographical error by reciting a “C2-C12-alkyl” rather than a “C1-C12-alkyl,” and it asked the district court to correct the error. The district court declined Enanta’s request and found that the patent was invalid as anticipated. Enanta appealed.
The Federal Circuit affirmed the district court’s grant of summary judgment, holding that the patent could not claim priority from the provisional. The court first held that its precedent did not authorize the district court to correct an error in the provisional application. That precedent only permits (i) the USPTO to correct certain errors in reissue proceedings, and (ii) district courts to correct errors in issued patents when “the correction is not subject to reasonable debate.” The Federal Circuit noted that the dispute was not before the USPTO, that the alleged typographical error was in a provisional application rather than an issued patent, and that “a change from C2 to C1 has not been shown here to be a correction of an obvious error.” Thus, the district court did not have the authority to correct the provisional application. However, as the district court ultimately declined to correct the provisional application, it properly considered whether the uncorrected provisional application provided written description support for the issued patent’s claims.
The Federal Circuit affirmed the district court’s written description decision. Enanta’s expert had argued that the provisional must have conflated C2 and C1 in the relevant portion of the specification because it made the same mistake elsewhere in the provisional. The Federal Circuit disagreed. It held that “C1-alkyl was simply not disclosed in the ’048 provisional” and that “an expert opinion on a typographical error contained elsewhere in the ’048 provisional does not render the former fact disputed.” The court therefore affirmed the district court’s ruling that there was no genuine dispute that the provisional’s disclosure of compounds with a two-carbon alkyl group did not provide written description support for compounds with a one-carbon alkyl group. Because Enanta’s patent could not claim priority to its provisional, it was anticipated by Pfizer’s public disclosure of a compound with a one-carbon alkyl group.
Editor: Sean Murray
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