Patent Owners, Get Your Story Straight at the PTAB

Posted by Stuart Duncan Smith on May 17, 2017

Patent owners have long known that making consistent arguments during IPRs and in district court litigation is critical to preserve credibility. The Federal Circuit recently took that a step further by holding that patent owners can be prevented from making arguments in district court that contradict their arguments in an IPR. More so than ever, patent owners must watch what they say during an IPR.

The rule that patent owners are held to what they said to the Patent Office is not new. Courts have long prevented patent owners from asserting a claim covers a certain subject matter after clearly stating during prosecution that the claim would not cover that subject matter. The doctrine is known as prosecution history disclaimer and can apply, for example, when the applicant distinguishes prior art but later asserts the claim covers the same scope.

The doctrine generally makes sense. Applicants should not be able to tell the Patent Office that the claims are narrow to get the patent issued but then tell the district court that the claims are broad to justify a broad infringement theory. When the patent owner’s statement to the Patent Office is clear, members of the public should be able to rely on that.

Despite that history, what was unknown until now was whether statements from patent owners facing an IPR have the same effect. Much like applicants seeking allowance of their claims, patent owners trying to avoid a finding of unpatentability in an IPR often have to distinguish prior art. Some patent owners do so by saying that the claims do not cover some subject matter that the prior art discloses.

In Aylus Networks, Inc. v. Apple Inc., No. 2016-1599 (May 11, 2017), the Federal Circuit held that a patent owner’s clear statements during an IPR will have the same effect as an applicant’s statement made during initial examination. What’s more, the court held that a patent owner’s statements made before the IPR is even instituted (e.g., in a patent owner preliminary response) will also have the same effect. All the more reason for patent owners to get their story straight before responding to an IPR petition.


  • Patent owners involved in district court litigation and IPRs have to think carefully about how their arguments in an IPR will affect their infringement theories. The fact that IPRs occur after issuance does not prevent the traditional rule of prosecution history disclaimer from applying.
  • For petitioners, this decision further counsels to file IPRs quickly. If properly timed, a patent owner may have to face the uncomfortable situation of imperiling its infringement theories to save its patents.

Topics: Patent Owners

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