Tag: invalidity
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Enanta v. Pfizer: Federal Circuit Rejects Provisional Priority Based on an Alleged Typographical Error
The Federal Circuit’s decision in Enanta Pharmaceuticals, Inc. v. Pfizer Inc., Case No. 2025-1427 (Fed. Cir. June 23, 2026), holds that a later patent cannot claim the filing date of a provisional application when the provisional expressly discloses a different chemical range, even if the applicant contends that the difference resulted from a typographical error.…
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Ironburg v. Valve: Federal Circuit Clarifies How Parties Must Prove IPR Estoppel Under §315(e)
The Federal Circuit’s decision in Ironburg Inventions Ltd. v. Valve Corp., Case No. 2024-2088 (Fed. Cir. June 18, 2026), limits when a patent owner may use inter partes review estoppel to prevent an accused infringer from asserting prior-art invalidity grounds in district court. The court held that a reference is not necessarily discoverable merely because…
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Brita v. ITC: Functional Genus Claims Fail Written Description and Enablement
The Federal Circuit’s October 15, 2025 decision in Brita LP v. International Trade Commission delivers a clear warning to patentees who rely on broad, functionally defined genus claims without commensurate disclosure. Affirming the ITC, the court held that claims covering any gravity-fed water filter media achieving a particular performance metric failed both the written description…