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Federal Circuit Affirms Pfizer Wins Enanta Patent; Light & Wonder Voids PTAB

Published
Score
12

Why it matters

The Federal Circuit affirmed summary judgment of anticipation in Enanta Pharmaceuticals v. Pfizer, invalidating Enanta's patent after the company failed to dispute anticipation absent an earlier priority date. In a separate development, the PTAB Director vacated institution decisions and denied petitions in Light & Wonder, effectively blocking the administrative trial entirely. Both rulings, issued in late June 2026, establish precedent affecting how courts and the Patent Trial and Appeal Board handle validity challenges.

The Enanta decision turns on Enanta's failure to contest the anticipation argument without establishing an operative priority date, allowing the Federal Circuit to affirm the district court's invalidity ruling. The Light & Wonder outcome remains less detailed—the PTAB Director's rationale for vacating prior institution decisions and denying the petitions outright has not been fully disclosed.

These rulings carry immediate weight for pharmaceutical and gaming patent holders. The Enanta decision reinforces strict requirements for priority date arguments in anticipation defenses, while the Light & Wonder ruling signals the PTAB Director's willingness to block trials at the institution stage. Practitioners should expect these precedents to reshape validity challenge strategies and clarify the scope of administrative authority in patent disputes.

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