PTAB Year in Review – Developments at the PTAB and Federal Circuit in § 102(e) Jurisprudence

Establishing that a reference qualifies as prior art is a crucial threshold inquiry in inter partes review (IPR) practice. In addition to the common tasks of establishing an earlier date and public accessibility, a developing body of case law has recently challenged what it means for U.S. published patent applications and issued patents to be filed “by another” under pre-AIA 35 U.S.C. § 102(e), and whether § 102(e)(1) art can even be used in IPRs in the first place.

In Hopewell Pharma Ventures, Inc. v. Merck Serono S.A.,¹ the Patent Trial and Appeal Board (PTAB) addressed § 102(e)’s “by another” requirement and articulated a framework for patent owners seeking to disqualify art as representing the work of a “common inventive entity.” Meanwhile, the Federal Circuit recently answered a more fundamental question as to whether § 102(e)(1) art may be used in IPRs in the first place. In Lynk Labs, Inc. v. Samsung Electronics Co.² the court answered in the affirmative, holding that such art can in fact be considered by the PTAB in assessing patentability challenges.

Examining the “by Another” Requirement

Hopewell addressed the patentability of two of Merck’s multiple-sclerosis treatment patents based on a patent application publication that Hopewell argued qualified as prior art under pre-AIA §§ 102(a) and (e). Merck tried to show that the relevant disclosure from the prior-art reference represented work from the inventors of the challenged patent such that the reference was not truly “by another.”

The Board articulated a burden-shifting framework for making that assessment. First, the petitioner must make an initial showing that there is no facial overlap in the named inventors or assignees of the prior-art reference and the challenged patent. The PTAB found that Hopewell satisfied that burden since the listed inventors of the challenged patent were different from those listed on the prior-art reference.

Second, the burden of production shifts to the patent owner to come forward with evidence showing that all named inventors—and only the named inventors—of the challenged patent provided an inventive contribution to the relevant disclosure in the prior-art reference. The PTAB held that Merck failed to make such a showing. Merck argued that, through a collaboration agreement, the challenged-patent inventors were responsible for the dosing regimen disclosed in the prior-art reference, which was the basis for Hopewell’s obviousness challenge. The PTAB disagreed, finding that Merck failed to produce evidence showing that all of the inventors of the challenged patent in fact made an inventive contribution to the relevant disclosure. In so holding, the PTAB rejected Merck’s argument that there need not be complete overlap in inventorship for the reference to be disqualified. The Board also determined that, even if all inventors had made an inventive contribution to the dosing regimen disclosed in the prior-art reference, Merck failed to show that the inventors contributed to other portions of the reference on which Hopewell relied.

Hopewell thus highlights the stringency of the “by another” requirement and the importance that patent owners proffer evidence as to the inventive contribution of all inventors to the entirety of the prior-art disclosure relied upon by a petitioner.

Applicability of § 102(e) Art in PTAB Challenges

In Lynk Labs, the Federal Circuit addressed whether a published patent application that has been subsequently abandoned, and which qualifies as art under § 102(e)(1), may be used in an IPR.

Enacted in 1999, § 102(e)(1) creates so-called “secret springing” prior art—i.e., patent applications that, although published after the challenged patent, were filed before the patent.³ Such applications are “secret” until they are published, at which time they “spring” into existence as prior art, back-dated to the time of their filing.⁴ For nearly thirty years, it has been well understood that such patent applications could serve as invalidating prior art. For the past decade, moreover, nobody questioned whether such art could be used in IPRs.

Until now. Lynk argued that, under § 311(b), IPRs may only be based on “prior art consisting of patents or printed publications.”⁵ And the Federal Circuit has long held that, to qualify as a “printed publication,” a reference must be “sufficiently accessible to the public interested in the art before” the challenged patent’s critical date.⁶ Indeed, “public accessibility” before the critical date is the “touchstone” of the “printed publication” inquiry.⁷ According to Lynk, it is unclear whether § 102(e)(1) patent applications so qualify because, even though such applications indisputably qualify as prior art, they are not publicly accessible before the challenged patent’s critical date. Other provisions of pre-AIA § 102 (sub-sections (a) and (b)) expressly refer to “printed publications,” thus reinforcing the notion that patent applications falling under sub-section (e)(1) do not qualify as printed publications. Accordingly, Lynk argued, such art cannot be used in IPRs.

The court rejected those arguments. Published patent applications, the court noted, indisputably qualify as “printed publications” in the literal sense of that phrase—they are “printed” and “published.” They are not published until after the challenged patent’s critical date, to be sure, but that is irrelevant because the meaning of “printed publication” is “temporally agnostic”—any temporal requirement as to when a reference must be published “is drawn from other language” in § 102.⁸ Here, published patent applications are prior art as of their filing date by virtue of § 102(e)(1), which the court noted creates “a special rule for published patent applications.”⁹ Consequently, such applications fall within the scope of § 311(b). In so holding, the court rejected Lynk’s distinction between § 102(e)(1)’s use of the phrase “applications for patent” and sub-sections (a)’s and (b)’s use of the phrase “printed publications,” noting that the former is simply a specific instance of the latter.

The court also rejected Lynk’s legislative history arguments based on longstanding precedent emphasizing the importance of public accessibility for determining whether a reference qualifies as a printed publication. Those “older cases,” the court noted, focused on non-patent application publications (e.g., books, articles, and the like) which, before 1999, were the only forms of printed publications that qualified as prior art.¹⁰ In the context of those references, the requirement that a reference be publicly accessible before the challenged patent’s critical date makes sense. But in the context of published patent applications, the court held, that requirement is inapposite. In short, “Congress chose to afford published patent applications a prior-art effect different from the effect given to” other types of printed publications.¹¹

Finally, the court noted that under Lynk’s theory, an IPR petitioner would have to carve § 102(e)(1) invalidity grounds out of a petition and pursue such grounds in district court, which would undermine some of the efficiencies that it appears Congress may have intended to achieve with IPRs. While Congress may have intended for some invalidity challenges to be adjudicated in district court—e.g., public-use-based defenses, which typically involve difficult evidentiary issues—§ 102(e)(1) art does not fall within the scope of such challenges.

The court thus upheld the Patent Office’s practice of treating so-called secret springing art as assertable in IPRs. This decision thus brings certainty to a longstanding but hotly contested practice.

[1] IPR2023-00480, Paper 62 (PTAB Sept. 18, 2024); IPR2023-00481, Paper 63 (PTAB Sept. 18, 2024). Sterne Kessler represented the petitioner, Hopewell.
[2] Appeal No. 23-2346 (Fed. Cir. Jan. 14, 2025).
[3] Post-AIA § 102(a)(2) has a similar provision, but this Article focuses on pre-AIA § 102(e)(1).
[4] If the patent applications are published before the challenged patent’s critical date, then they qualify as prior art under pre-AIA §§ 102(a) or (b).
[5] 35 U.S.C. § 311(b).
[6] Voter Verified, Inc. v. Premier Elections Sols., Inc., 698 F.3d 1374, 1380 (Fed. Cir. 2012) (cleaned up).
[7] Samsung Elecs. Co. v. Infobridge Pte., 929 F.3d 1363, 1369 (Fed. Cir. 2019).
[8] Appeal No. No. 23-2346, slip op. at 16-17.
[9] Id. at 8.
[10] Id. at 14.
[11] Id. at 18-19.