Prima Facie Lack of Novelty: When Prior Art Ranges Give Rise to Rebuttable Anticipation

This article was featured in the AIPLA Quartely Journal – Volume 53, Issue 2, Page 277, Spring 2025.

The Court of Appeals for the Federal Circuit has well-established standards for determining whether a claimed numerical range is prima facie obvious under 35 U.S.C. § 103, over a prior art reference disclosing a similar range. In instances of prima facie obviousness, the patent applicant or patentee (hereafter “claim owner”) can rebut such challenge by producing evidence of objective indicia of non-obviousness. By contrast, if the prior art reference discloses a point or a smaller range within the claimed range, the prior art conclusively anticipates the claimed range under 35 U.S.C. § 102, and the claim owner cannot rebut such anticipation. It is fair to say that the law on prima facie obviousness and conclusive anticipation of claimed numerical ranges is stable.

This stability is not so with the doctrine of rebuttable anticipation, which provides a framework for analyzing situations when a prior art range overlaps with part, or abuts the endpoint, of a claimed range. This doctrine is relatively young. The decisions of the court on rebuttable anticipation have not always been consistent or clear. It is only relatively recently that the court seems to have settled on the requirements for prima facie anticipation and its rebuttal.

Curiously, the literature is sparse in its discussion of recent developments in the analysis of novelty or obviousness of overlapping ranges. Some commentators have limited themselves to discussing individual cases. Others have compared different national or regional approaches to the patentability of ranges. The USPTO, in its Manual of Patent Examining Procedure discusses how to analyze overlapping ranges for anticipation, but does not provide a broader overview of the field. No publication has analyzed in detail the doctrine of prima facie anticipation of overlapping ranges and its relevance to the overall case law dealing with the subject. This Article aims to fill the gaps.

This Article will provide a contextual and historical survey and analysis of decisions in the area of claimed and prior art numerical ranges. Our analysis will hopefully offer clarity and guidance to the patent law community. We will first provide an overview of the Federal Circuit’s well-established standards for determining whether a claimed range is prima facie obvious over or whether it is conclusively anticipated by the prior art. These are relatively settled areas of the law. We then analyze situations when the Federal Circuit has applied a prima facie anticipation analysis and has explained how to rebut it.

Finally, this Article includes a flowchart that will help practitioners navigate the many issues that arise when confronting disclosures of ranges in the prior art. The flowchart provides guidance on how to analyze prior art ranges, including those that (1) conclusively anticipate, (2) raise only prima facie obviousness, or (3), in a situation of partly overlapping ranges, raise both prima facie obviousness and prima facie anticipation.

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