Mark Deming and Chad Landmon discuss the Federal Circuit's decision in Enanta Pharmaceuticals Inc. v. Pfizer Inc., which underscores the importance of carefully drafting provisional patent applications to preserve priority claims. They explain that the court found Enanta's provisional application did not adequately support the broader patent claims ultimately asserted, leaving those claims vulnerable to intervening prior art and resulting in invalidation. Deming and Landmon emphasize that the decision serves as an important reminder for life sciences companies and patent practitioners to ensure provisional applications fully support future claim scope in order to safeguard valuable intellectual property.