Federal Circuit Clarifies that Enablement of Prior Art is a Separate (and Distinct) Inquiry from Enablement of Claims in a Patent

July 1, 2025

Reading Time : 3 min

By: Rachel J. Elsby, Chloe Fan (Law Clerk)

In an appeal from an inter partes review, the Federal Circuit recently clarified that the enablement inquiry applied to prior art references in the context of an anticipation defense differs from the enablement inquiry applied when evaluating the claims of a patent.

In this case, Petitioner-Appellee Synthego Corporation (Synthego) filed two IPR petitions challenging claims of U.S. Patent No. 10,337,001 B2 (“the ’001 patent”) and U.S. Patent No. 10,900,034 (“the ’034 patent”), both of which relate to CRISPR-Cas systems for gene editing and share a common priority date of December 3, 2014. In the IPRs, the Patent Trial and Appeal Board (“PTAB”) issued two final written decisions, finding all of the challenged claims unpatentable as anticipated and obvious. Patentee-Appellant Agilent Technologies, Inc. (Agilent) appealed.

At the PTAB, Agilent argued that it would have been extremely challenging for a person of ordinary skill in the art to synthesize the claimed chemically modified RNA molecules in the claims. Agilent also stated that the nascent state of the art demonstrated that undue experimentation would be required. The Board rejected this argument, finding that by the December 2014 priority date, substantial research had been published in the area, and therefore, a POSA would not have been working from a blank slate. Rather, the art provided standard techniques to make the RNA molecules exemplified in the anticipatory reference. And the types of modifications used in the prior art had been known for decades to stabilize RNA.

On appeal, Agilent raised multiple arguments including that the PTAB’s anticipation determination was not supported by substantial evidence because the anticipatory reference was not enabled.

The Federal Circuit rejected Agilent’s non-enablement argument, affirming the PTAB’s anticipation determination. In reaching its decision, the court distinguished its prior decision in Impact Labs., Inc. v. Aventis Pharms., a case where the court held that a prior art reference was not enabling because it disclosed an extensive range of compounds and broad dosage guidelines without sufficient direction or guidance to prescribe a treatment regimen. By contrast, here the prior art disclosed specific sequences having the recited chemical modifications at the recited locations which had been known and used for decades to stabilize RNA against degradation.

The Federal Circuit also distinguished the Supreme Court’s decision in Amgen Inc. v. Sanofi, 598 U.S. 594 (2023), explaining that the issue in Amgen concerned whether the asserted claims were sufficiently enabling to be valid under 35 U.S.C. § 112, whereas the present case involved whether a prior art reference was enabling for purposes of anticipation. And these are two separate inquiries—Section 112 requires that the specification enable a POSA to use the invention, whereas Section 102 makes no such requirement for an anticipatory disclosure. Additionally, Section 112 requires that a specification enable the full scope of the claims, whereas Section 102 only requires that a prior art reference enable a single embodiment.

Although there was evidence here that a POSA would have needed to engage in some level of experimentation, the PTAB’s finding that a POSA would have understood how the elements of the claim functioned together, particularly because the types of chemical modifications needed here had been successfully used in other systems to reduce RNA degradation, i.e., the same purpose they were used for here. Based on this record, the Federal Circuit held that substantial evidence supported the PTAB’s finding that the prior art was enabled.

Practice Tip: This case highlights that enablement challenges brought against prior art face a different, and potentially more challenging, inquiry because the inquiry is less focused on the breadth of the claims and more focused on whether a POSA could have made an embodiment of the invention. As to that question, it will be important to look not only at the relevant disclosures in the prior art reference itself, but also the knowledge of a POSA.

Agilent Techs., Inc. v. Synthego Corp., No. 2023-2186, 2025 WL 1645693 (Fed. Cir. June 11, 2025)

Share This Insight

Previous Entries

IP Newsflash

July 1, 2025

In an appeal from an inter partes review, the Federal Circuit recently clarified that the enablement inquiry applied to prior art references in the context of an anticipation defense differs from the enablement inquiry applied when evaluating the claims of a patent.

...

Read More

IP Newsflash

June 26, 2025

The Northern District of Ohio denied a motion to compel the plaintiff to produce test results referenced in its initial disclosures and complaint. The court found that because the “test results are not facts but rather are opinions,” the information was protected as work product. Furthermore, because that testing would not be used as evidence in the litigation, the defendant was not prejudiced.

...

Read More

IP Newsflash

June 6, 2025

In a precedential opinion, the Federal Circuit definitively held that the Patent Trial and Appeal Board has jurisdiction over IPRs that concern expired patents.

...

Read More

IP Newsflash

June 6, 2025

In a patent infringement litigation in the U.S. District Court for the Eastern District of Texas, Judge Rodney Gilstrap denied a joint motion to stay the litigation pending resolution of inter partes review when it was uncertain that all defendants would be bound by the statutory estoppel provision of 35 U.S.C. § 315(e).

...

Read More

IP Newsflash

May 30, 2025

A district court recently dismissed a patent infringement complaint for improper venue under 28 U.S.C. § 1400(b), finding that the storage and distribution of products from an Amazon warehouse was not sufficient to establish that warehouse as a regular and established place of business in the district.

...

Read More

IP Newsflash

May 27, 2025

The Federal Circuit affirmed a District of Delaware finding of non-infringement in an ANDA litigation due to the patentee’s clear and unmistakable disavowal of claim scope during prosecution. Specifically, the court held that statements made during prosecution of a parent application before the asserted claims were allowed amounted to a prosecution disclaimer that extended to subsequent patents in the family. In reaching this conclusion, the court rejected an attempt by the patentee to resurrect the claim scope through a unilateral, self-serving statement made in later applications in the family.

...

Read More

IP Newsflash

May 13, 2025

The Federal Circuit recently affirmed a district court’s holding that patent term extension (PTE) for a reissued patent was properly based on the issue date of the original patent and not that of the reissued patent. The Federal Circuit concluded that, where both the original and reissued patents claimed a drug product under regulatory review, using the issue date of the original patent to calculate PTE comports with both the purpose of the Hatch-Waxman Act and the related statutory context.

...

Read More

IP Newsflash

May 12, 2025

The Patent Trial and Appeal Board recently declined to institute a petition for IPR that was filed on the same day that the petitioner filed another petition challenging the same claims of the same patent. The board was not persuaded by petitioner’s arguments that a second petition was needed due to alleged claim construction issues or the number, length or scope differences of the challenged claims.

...

Read More

© 2025 Akin Gump Strauss Hauer & Feld LLP. All rights reserved. Attorney advertising. This document is distributed for informational use only; it does not constitute legal advice and should not be used as such. Prior results do not guarantee a similar outcome. Akin is the practicing name of Akin Gump LLP, a New York limited liability partnership authorized and regulated by the Solicitors Regulation Authority under number 267321. A list of the partners is available for inspection at Eighth Floor, Ten Bishops Square, London E1 6EG. For more information about Akin Gump LLP, Akin Gump Strauss Hauer & Feld LLP and other associated entities under which the Akin Gump network operates worldwide, please see our Legal Notices page.