Prior art

The U.S. Patent and Trademark Office (USPTO) database confirms that US Patent 11358953, titled "Functionalized peptides as antiviral agents," was issued on June 14, 2022, to Enanta Pharmaceuticals Inc..

Identifying the "most relevant" prior art for US Patent 11358953 is complicated by the recent Federal Circuit (CAFC) decision. The CAFC ruled all claims of US11358953 invalid because the patent could not claim the priority date of its provisional application (U.S. Provisional Application No. 63/054,048, filed on July 20, 2020) due to inadequate written description for a C1-alkyl group. This made Pfizer's public disclosure of nirmatrelvir in April 2021 anticipatory prior art.

Therefore, the most relevant prior art, as determined by the CAFC, is:

1. Pfizer's Public Disclosure of Nirmatrelvir

• Full Citation: Not a formal patent or publication citation in the traditional sense, but rather a public disclosure event.
• Publication/Filing Date: April 2021.
• Brief Description: This refers to the public disclosure of nirmatrelvir by Pfizer. Nirmatrelvir, a key component of Pfizer's COVID-19 antiviral Paxlovid, contains a one-carbon alkyl group.
• Which Claim(s) it Potentially Anticipates under 35 U.S.C. § 102: All claims of US11358953. The CAFC found that because the '953 patent could not claim the benefit of its earlier provisional application, Pfizer's April 2021 disclosure of nirmatrelvir anticipated all asserted claims, leading to their invalidation under 35 U.S.C. § 102.

While other patent and non-patent citations exist within the US11358953 document, the CAFC's ruling specifically highlighted Pfizer's public disclosure of nirmatrelvir as the anticipatory prior art that rendered all claims invalid due to the priority date issue. The prior art references listed on the face of the patent itself would typically be considered during prosecution by the patent examiner; however, the CAFC's decision on the priority date supersedes those, making Pfizer's disclosure the pivotal prior art in the current legal status of the patent.