Petitioner’s Failure to Argue that Prior Art was Analogous to Challenged Patent Results in Reversal of IPR Decision

By Chris Holman

Sanofi-Aventis Deutschland GMBH v. Mylan Pharms Inc., 2023 WL 3311549, — F.4th — (Fed. Cir. May 9, 2023).

The “analogous arts” test is used in patent law to determine whether a particular reference is relevant for the purposes of an obviousness analysis. Under this two prong test, a reference is relevant if it is from the same field of endeavor as the invention at issue, or if it is reasonably pertinent to the problem the invention is trying to solve.  In re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004)

In its 2007 KSR v. Teleflex decision, the Supreme Court ruled that the obviousness analysis should be more flexible and not confined to rigid rules or tests. Rather, KSR emphasized an “expansive and flexible approach” to obviousness.  While KSR did not directly address the analogous arts test, it could be interpreted as calling for a more flexible approach allowing courts and the PTO more leeway to consider prior art from a broader range of sources as being “analogous” or “reasonably pertinent,” which in principle should make it easier for challengers to invalidate patents.

In inter partes review (IPR) proceedings, the Patent Trial and Appeal Board (PTAB) has invalidated patents claims for obviousness based on cited prior art that the PTAB found to be analogous, and until now the Federal Circuit has consistently affirmed those decisions on appeal.  Unwired Planet, LLC v. Google Inc., 841 F.3d 995 (Fed. Cir. 2016); Smartdoor Holdings, Inc. v. Edmit Indus., Inc., 707 F. App’x 705 (Fed. Cir. 2017); Toyota Motor Corp. v. Reactive Surfaces Ltd., LLP, 816 F. App’x 480 (Fed. Cir. 2020); CyWee Grp. Ltd. v. Google LLC, 847 F. App’x 910 (Fed. Cir. 2021); and Kamstrup A/S v. Axioma Metering UAB, 43 F.4th 1374 (Fed. Cir. 2022)).

On occasion, the PTAB has found cited prior art to be non-analogous, and thus irrelevant for purposes of the obviousness inquiry.  The Federal has twice affirmed those decisions on appeal.   Polygroup Ltd. MCO v. Willis Elec. Co., Ltd, 759 F. App’x 934 (Fed. Cir. 2019) and Broadcom Corp. v. Int’l Trade Comm’n, 28 F.4th 240 (Fed. Cir. 2022)).  In one reported decision, Donner Tech., LLC v. Pro Stage Gear, LLC, 979 F.3d 1353 (Fed. Cir. 2020), the Federal Circuit vacated and remanded after concluding that the Board had applied the wrong standard when it determined that a cited prior art reference was not analogous art.

On May 9, in Sanofi-Aventis Deutschland GmbH v. Mylan Pharms. Inc., the Federal Circuit held for the first time (to the best of my knowledge) that the PTAB erred in finding cited prior art to be analogous in an IPR.  Significantly, the Federal Circuit’s decision did not address the merits of the analogous art question, but instead was based entirely on the fact that the patent challenger (Mylan) had failed to allege that the cited prior art was analogous to the challenged patent (U.S. Patent No. RE47,614, which relates to pen injectors used for the delivery of drugs such as insulin).

The court observed that:

A petitioner is not required to anticipate and raise analogous art arguments in its petition; instead a petitioner can use its reply to “respond to arguments raised in the corresponding opposition, patent owner preliminary response, patent owner response, or decision on institution.” See 37 C.F.R. § 42.23. However, Mylan did not use its reply to explain how de Gennes is analogous to the ‘614 patent.

The court reversed the PTAB’s finding of nonobviousness because it had relied upon a finding that the de Gennes reference was analogous prior art, but Mylan had never made the required analogous art argument. Mylan argued on appeal that it had, in its IPR petition, effectively argued that the de Gennes reference was analogous to another other cited prior art reference, i.e., Burren, and that Burren and the challenged Sanofi patent address the “same problem.”  However, the court found Mylan’s arguments as to Burren insufficient to carry its burden because they did not directly address the challenged patent.

The court explained that:

In evaluating whether a reference is analogous, we have consistently held that a patent challenger must compare the reference to the challenged patent. This conclusion is reinforced by the purpose of the analogous art test, which is to examine whether a reference can be considered as prior art to the challenged patent in the first place. [The] purpose of the “prior art” must be evaluated with reference to the inventor’s purported invention disclosed within the challenged patent.


11 thoughts on “Petitioner’s Failure to Argue that Prior Art was Analogous to Challenged Patent Results in Reversal of IPR Decision

  1. 5

    I was concerned about a burden-shifting issue here re non-analogous art arguments to remove Petitioner cited art, but the Fed. Cir. decision notes that [already before the IPR trial]:
    “In its patent owner [response, Sanofi argued that de Gennes is not analogous art to the ’614 patent. J.A. 2309. Sanofi argued that de Gennes relates to cars and not drug delivery devices or medical devices, such that a person of ordinary skill in the art “would not have considered a clutch bearing to be within the same field of endeavor.” J.A. 2310. Sanofi further argued that de Gennes is not “reasonably pertinent” to the ’614 patent’s problem, J.A. 2312, which it asserted is “secur[ing] a cartridge against movement within a housing.” J.A. 2313; accord J.A. 2415 (Sanofi’s expert).”

  2. 3

    I don’t think the last quoted paragraph is entirely accurate. Even if a reference fails the analogous art test, it still “can be considered as prior art to the challenged patent in the first place.” It would just be non-analogous art for 103 purposes.

    1. 3.1

      And the 3 cases cited in the underlying opinion (but omitted from the quote) also don’t support that point either.

  3. 2

    Whenever a reference cited by the Examiner appears non-analogous to me, I argue that the reference is non-analogous. It mostly happens when an Examiner is stretching the limits of hindsight to make that 103 rejection and can’t find a reference in their own art.

    1. 2.1

      At the risk of the Design Guru’s admonition, let’s tip toe into “analogous” for design patents…

    2. 2.2

      How often is that successful?

      I tend to argue it too, but only as a secondary reason.

      1. 2.2.1

        For some reason, it’s successful more often with Primary Examiners then Junior Examiners, because the gut instinct is that the Primary Examiner is just going to blow off the argument. Overall, it’s generally successful when I also include a declaration from one of the inventors. There have been times when the Examiner tried to rebut that the declaration was just the inventor’s opinion but then I call the SPE and point out that the declaration is evidence that the Examiner has to rebut with more than just a conclusion, and more often than not, the Office Action is “supplemented” by a new Office Action that does not use the reference. It’s case-by-case.

  4. 1


    Not all prior art (as may be suitable for any 102) is suitable for 103.

    103 is not a mere “more than one reference” set of individual “items of 102.”

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