According to 35 U.S.C. §315(a), an inter partes review may not be instituted if, before the date on which the petition for such a review is filed, the petitioner or real party in interest filed a civil action challenging the validity of a claim of the patent. In a recent decision, the Patent Trial and Appeal Board dealt with the issue of whether a petition would be barred under Section 315(a) when the petitioner previously had raised an affirmative invalidity defense as part of a motion to intervene as a defendant in a federal patent infringement suit. The Board decided that the petition was not barred by Section 315(a) and instituted a trial on the merits. (IPR2015-01872, Paper 10, March 14, 2016.)

Ericsson Inc. (the Petitioner) filed a petition to institute an inter partes review of claims 1-25 of U.S. Patent No. 7,385,994 of Intellectual Ventures II LLC (the Patent Owner). In a preliminary response, the Patent Owner argued that the Petition was time barred under Section 315(a) because prior to the IPR Petition Ericsson had filed a motion to intervene as a defendant in a patent infringement litigation, initiated by the Patent Owner against AT&T and Cingular Wireless, along with an Answer in Intervention, in which the Petitioner had raised an affirmative defense of invalidity of the ‘994 patent. The Patent Owner characterized the intervention initiated by the Petitioner as “initiating a new dispute,” when none existed beforehand.

The Board disagreed with the Patent Owner and relied on the reasoning put forth in Ariosa Diagnostics v. Isis Innovation Limited (IPR2012-00022) to hold that Ericsson’s answer did not constitute a civil action challenging the validity of a claim of a patent.

In Ariosa, the petitioner had filed an action for a declaratory judgment of non-infringement, and in response, the patent owner had counterclaimed for infringement. The petitioner had then raised an affirmative defense of invalidity. The Ariosa panel relied on Supreme Court precedent to explain that there is a fundamental difference between an affirmative defense of invalidity and a declaratory judgment action asserting patent invalidity. The Ariosa panel held that the reference to a civil action in Section 315(a) refers to filing of a complaint to commence a civil action, and not an answer.

The Board in the present IPR followed Ariosa’s reasoning and indicated that the “Patent Owner does not point to persuasive authority that an answer in intervention should be treated differently than an answer responding to infringement counterclaims.” Thus, the Board concluded that the Petition was not barred by Section 315(a).