Summary
The United States Court of Appeals for the Federal Circuit affirmed summary judgment that all claims of Enanta Pharmaceuticals’ U.S. Patent No. 11,358,953 were invalid as anticipated by Pfizer’s public disclosure of nirmatrelvir. The court held that the earlier provisional application’s disclosure of a C2-C12 alkyl group did not provide written-description support for the patent’s later disclosure of a C1-C12 alkyl group, so the patent was not entitled to the provisional application’s priority date.
Topics
Practice areas
Questions Presented
- Whether the provisional application provided adequate written-description support under 35 U.S.C. § 112 for the later patent's disclosure and claims covering an NHC(O)-C1-alkyl substituent.
- Whether the alleged discrepancy between C2-C12 alkyl in the provisional and C1-C12 alkyl in the later patent created a genuine dispute of material fact sufficient to preclude summary judgment.
- Whether Pfizer's public disclosure of nirmatrelvir anticipated the asserted claims if the '953 patent was not entitled to the provisional application's priority date.
Holdings
- The '048 provisional application did not provide adequate written-description support for the '953 patent's disclosure of NHC(O)-C1-alkyl because it expressly disclosed only NHC(O)-C2-C12-alkyl and did not disclose the one-carbon alkyl group.
- The expert testimony and other evidence offered by Enanta did not create a genuine dispute of material fact concerning whether the provisional disclosed or supported C1-alkyl.
- Because the '953 patent was not entitled to the provisional application's priority date, Pfizer's earlier public disclosure of nirmatrelvir anticipated the patent claims, and summary judgment of invalidity was proper.
Key quotations
“We conclude that the ’048 provisional does not convey to a skilled artisan that the inventors possessed —NHC(O)—C1-alkyl at the time of the ’048 provisional’s filing date.” (8)
“As we have explained, “[e]ntitlement to a filing date . . . extends only to that which is disclosed,” Lockwood, 107 F.3d at 1571–72, and —NHC(O)—C1-alkyl was simply not disclosed in the ’048 provisional.” (9)
“The ’048 provisional did not disclose —NHC(O)—C1-alkyl. It therefore provided no written description support for the ’953 patent, so the ’953 patent cannot be afforded the ’048 provisional’s priority date.” (10)
Factual background
Enanta's '953 patent claims compounds and methods for inhibiting coronavirus replication and claimed priority to a July 20, 2020 provisional application. The provisional disclosed an NHC(O)-C2-C12-alkyl substituent, while the later patent disclosed NHC(O)-C1-C12-alkyl; Enanta asserted that the C2 designation in the provisional was a typographical error. Pfizer publicly disclosed nirmatrelvir on April 6, 2021, before the filing date of the nonprovisional application, and the district court concluded that this disclosure anticipated the patent claims because the provisional did not support the asserted priority date.
Procedural history
Enanta sued Pfizer in June 2022 for infringement of the '953 patent. Pfizer counterclaimed for invalidity and moved for summary judgment on anticipation, arguing that the patent could not claim priority to Enanta's provisional application because the provisional did not provide written-description support for the C1-C12 alkyl limitation. The district court granted Pfizer's motion, and the Federal Circuit affirmed.