A provisional patent application is not just a placeholder.
The Federal Circuit’s recent decision in Enanta Pharmaceuticals v. Pfizer is a good example of why the details in a provisional matter.
Enanta’s provisional disclosed a C₂–C₁₂ alkyl range. The later nonprovisional expanded that range to C₁–C₁₂.
That one-carbon difference ended up being critical.
The court found that the provisional did not provide adequate written-description support for the C₁ subject matter. As a result, Enanta lost the benefit of its provisional filing date, and Pfizer’s intervening disclosure of nirmatrelvir became prior art that anticipated the claims.
The takeaway is straightforward: your provisional needs to support and enable the claims you may want to pursue in the nonprovisional.
When I prepare a provisional application, I do not look at it as simply getting something on file. I think about how the invention may be claimed later, including reasonable variations, alternatives, ranges, endpoints, and broader versions of the invention.
The question is not just, “Does this describe the invention today?”
The question is also, “Will this support the claims we may need tomorrow?”
At Darryl Scott Law, the goal is to build a strong foundation from the beginning. Because in patent law, what looks like a small detail today can determine whether your priority date—and your patent rights—survive later.
Read the Federal Circuit’s June 23, 2026 decision:
Enanta Pharmaceuticals, Inc. v. Pfizer Inc.
https://www.cafc.uscourts.gov/opinions-orders/25-1427.OPINION.6-23-2026_2712960.pdf
