Raising Affirmative Defense Of Invalidity In An Answer Does Not Deprive A Party Of Standing To Seek Inter Partes Review

In IPR2012-00022, the Patent Trial and Appeals Board ("PTAB") (A.P.J.s Tierney, Green and Robertson) issued an order in Ariosa Diagnostics ("Petitioner") v. Isis Innovation Limited ("Patent Owner") regarding Ariosa's standing. Section 315 specifies that "[a]n inter partes review may not be instituted if, before the date on which the petition for such review is filed, the petitioner or real party in interest filed a civil action challenging the validity of a claim of the patent." Notably, however, Section 315 exempts the filing of a counterclaim challenging the validity of a claim of a patent from the definition of a "civil action." 35 U.S.C. § 315 (a)(3). The issue presented here is whether raising the defense of invalidity in an affirmative defense falls with the definition of a "civil action" under Section 315.

Ariosa filed a civil action against the exclusive licensee of U.S. Patent No. 6,258,540 seeking a declaration that it did not infringe any claim of the '540 Patent. In the declaratory judgment action, the exclusive licensee counterclaimed for infringement. In response, Ariosa answered by raising the affirmative defense of invalidity of the '540 patent. According to Isis, the fact that Ariosa challenged the validity of the '540 patent claims in an affirmative answer rather than a complaint "is of no moment." Isis argued that section 315(a)(3) exemption is limited to a counterclaim and does not include affirmative defenses. Thus, the Board was presented with the issue of whether the Section 315 deprives a party of standing when that party raise the defense of invalidity in its answer in response to a counterclaim of infringment.

The Board relied on the definition of "civil action" set forth in the Federal Rules of Civil Procedure and held that it refers to the filing of a complaint to "commence" a civil action:

Rule 2 of the Federal Rules of Civil Procedure1 states that "[t]here is one form of action--the civil action," and Rule 3 states that "[a] civil action is commenced by filing a complaint with court." Defenses are raised in answer to the complaint or in answer to a counterclaim. Fed. R. Civ. P. 12. We thus conclude that when the statute refers to filing a civil action, it refers to filing a complaint with the court to commence the civil action. See, e.g., Baldwin Cnty Welcome Ctr v. Brown, 466 U.S. 147, 149 (1984) (citing Fed. R. Civ. P...