35 U.S.C. § 315(b)’s time bar applies even where complaint was voluntarily dismissed

This was an appeal from a final written decision of the Patent Trial and Appeal Board (PTAB). The PTAB had rejected the patent owner’s argument that the petition was time-barred under 35 U.S.C. § 315(b) because petitioner had been served with a complaint years before the petition was filed.  Applying Federal Circuit case law suggesting that when a complaint is dismissed without prejudice it is treated as if it is never filed, the PTAB disagreed with patent owner’s arguments because the earlier-filed complaint had been dismissed without prejudice.

At issue on appeal was whether the PTAB erred in interpreting Section 315(b)’s bar as not triggered by a complaint that is later dismissed without prejudice. Section 315(b) provides that an inter partes review(IPR) “may not be instituted if the petition requesting the proceeding is filed more than 1 year after the date on which the petitioner…is served with a complaint alleging infringement of the patent.” The en banc court, in a footnote, concluded that the PTAB’s interpretation of section 315(b) was improper. The panel opinion explains that it is “wholly irrelevant to the § 315(b) inquiry whether the civil action in which the complaint was filed is later voluntarily dismissed without prejudice.” The PTAB erred because its construction of the statute imposed the additional condition not present in the statute’s text that the served complaint not be dismissed.  

Therefore, under this decision, if a party is served with a complaint, that party must consider whether to challenge the patent in an IPR even if the suit is dismissed without prejudice or be barred from doing so if the patent is asserted again in a later-filed suit.

A copy of the opinion can be found here