Uniloc 2017 v. Hulu: Federal Circuit Says PTAB’s Review of Substitute Claims Is Not Limited to Anticipation and Obviousness

Per the express language of 35 U.S.C. § 311, a petitioner in an IPR may request cancellation of a claim “only on a ground that could be raised under section 102 or 103.” In other words, an issued claim can only be canceled via IPR on the basis of anticipation or obviousness grounds. But once an IPR is instituted, can the PTAB also make eligibility determinations pursuant to section 101 and/or written description or enablement determinations pursuant to section 112? The answer is, in certain circumstances, “yes” according to the Federal Circuit in Uniloc 2017 v. Hulu, No. 2019-1686 (Fed. Cir. July 22, 2020).

In Uniloc 2017, the petitioners challenged the patent owner’s claims as anticipated and obvious. The patent owner defended the claims and also filed a contingent motion to amend requesting that, in the event certain claims were found unpatentable, the PTAB issue substitute claims pursuant to section 316(d). The petitioners opposed the motion to amend, arguing that the proposed substitute claims were directed to patent ineligible subject matter.

In the Final Written Decision, the PTAB not only found the challenged claims to be unpatentable, but also found that the proposed substitute claims were directed to patent ineligible subject matter and denied the motion to amend. The patent owner then requested a rehearing, which the PTAB denied. On appeal to the Federal Circuit, the patent owner challenged the PTAB’s authority to consider patent eligibility of the proposed substitute claims.

The Federal Circuit held that the PTAB may consider subject matter eligibility for substitute claims in IPR, concluding that the PTAB is not limited to anticipation and obviousness by section 311 when reviewing such claims. Starting with the text of the statute, the Federal Circuit found that Congress had been clear and unambiguous on this point. In the eyes of the court, section 318’s requirement that the PTAB “issue a final written decision with respect to the patentability” of substitute claims makes clear that the PTAB’s review of substitute claims in IPR is not limited to anticipation and obviousness.

Further, the Federal Circuit reasoned that precluding the PTAB from considering the patent eligibility of proposed substitute claims would be inconsistent with the structure and legislative history of the IPR statute. For example, the court noted that, because proposed substitute claims in IPR have not undergone a prior patentability review by the USPTO, constraining the PTAB to anticipation and obviousness would allow a patent owner to side-step all other conditions for patentability on those claims.


Patent owners and petitioners should be mindful of this ruling when dealing with motions to amend in IPR. While the original claims may only be reviewed for anticipation and obviousness, substitute claims may undergo review for patent eligibility. Both parties should be prepared to set forth substantive arguments on patentability of substitute claims that consider all grounds for patentability.

Practitioners should also note the Federal Circuit’s other holding in this case: even if the challenged claims are invalidated in a separate case, which might moot the PTAB’s consideration of those claims in the IPR, the PTAB can still consider whether the proposed substitute claims are patentable.