Background
Parus Holdings, Inc. owns two patents directed to an interactive voice system that allows users to access web-based information through a voice interface — what might today be called an early voice assistant or voice web browser. Google, Samsung, and LG petitioned for inter partes review (IPR) of both patents, contending that the claimed inventions were anticipated or rendered obvious by prior art.
In response, Parus sought to establish that its inventors had conceived of and reduced the invention to practice before the prior art’s effective date — a defense known as antedating or swearing behind prior art. To support this defense, Parus submitted approximately 40 exhibits totaling over 1,300 pages, including claim charts and declarations describing the inventors’ conception, diligence, and reduction to practice as early as 1999. However, Parus’s briefs before PTAB only minimally cited small portions of this material and largely failed to explain its significance with specificity. Instead, Parus’s briefing effectively invited the Board to review the mass of exhibits and draw its own conclusions — an approach that amounts to incorporating arguments by reference.
PTAB found that Parus had violated 37 C.F.R. § 42.6(a)(3), which prohibits parties in PTAB proceedings from incorporating by reference arguments from other documents. The Board declined to consider Parus’s voluminous undiscussed exhibits and ruled against Parus on the antedating defense. Parus appealed, arguing that the Board’s refusal to consider its evidence violated the Administrative Procedure Act (APA).
The Court’s Holding
The Federal Circuit affirmed. The court rejected Parus’s argument that the APA required PTAB to wade through its 1,300 pages of exhibits and independently identify the arguments and evidence that Parus had neglected to articulate in its briefs. The court explained that the APA requires agencies to consider evidence and arguments that are properly presented to them — but it does not require agencies to consider evidence introduced in violation of their own procedural rules. Because Parus’s approach violated § 42.6(a)(3)’s prohibition on incorporating arguments by reference, PTAB had discretion to disregard the improperly presented material, and exercising that discretion did not constitute an APA violation.
The court emphasized the purpose behind the prohibition on incorporation by reference: PTAB proceedings have strict word and page limits designed to ensure that parties present their arguments efficiently and that the Board can adjudicate disputes without sifting through hundreds of pages of undiscussed exhibits. Allowing parties to effectively bypass these limits by dumping extensive exhibits and relying on the Board to find the relevant arguments would undermine the efficiency and predictability that the IPR system is designed to provide.
Key Takeaways
- PTAB’s prohibition on incorporating arguments by reference (37 C.F.R. § 42.6(a)(3)) means that parties must articulate their arguments in their briefs with specificity — voluminous exhibits left without adequate explanation in the brief will be disregarded.
- The APA does not require PTAB to consider evidence or arguments introduced in violation of the Board’s procedural rules; the APA operates on properly presented arguments, not on improperly filed material.
- When building an antedating defense in IPR, patent owners must connect specific exhibits to specific arguments in their briefing — the Board will not independently search through hundreds of pages of evidence to find support for arguments the patent owner failed to articulate.
- PTAB’s page and word limits are enforceable constraints; parties cannot circumvent them by filing extensive exhibits and directing the Board to review them without explanation.
Why It Matters
This decision is a cautionary tale for patent owners defending their patents in IPR proceedings. The instinct to submit comprehensive documentary evidence — every internal email, every lab notebook, every version of a prototype — to support a priority or antedating defense can backfire badly if that evidence is not accompanied by clear, brief-integrated explanations of what each piece shows and why it matters. PTAB proceedings are not like district court discovery, where voluminous document productions can be sifted through at trial; they are focused administrative proceedings with strict rules designed to keep the record manageable.
For patent practitioners handling IPR responses, the practical lesson is clear: every exhibit should be cited specifically in the brief, and every citation should be accompanied by an explanation of the exhibit’s significance to the argument being made. This is especially true for antedating defenses, which often involve large volumes of historical documentation. If the word or page limits make it impossible to fully explain all of the evidence, parties must make hard choices about which evidence is most critical and focus their briefs accordingly — or risk having the entire evidentiary record disregarded as improperly incorporated by reference.