Article
The One-Carbon Mistake That Cost A Patent Its Priority Date
In Enanta Pharmaceuticals, Inc. v. Pfizer Inc. No. 2025-1427 (Fed. Cir. June 23, 2026), one character did a lot of damage. The difference between C2 and C1 cost Enanta the priority date of its provisional application—and led the Federal Circuit to affirm that the challenged claims were anticipated.
Seyfarth Shaw LLP