Under 35 U.S.C. §315(e)(1), a petitioner who files a petition for inter partes review (IPR) that proceeds to a final written decision “may not assert … in a civil action … that the claim [at issue in the IPR] is invalid on any ground that the petitioner raised or reasonably could have raised during that” IPR. This estoppel provision has been the subject of a number of Federal Circuit and district court decisions. Most of these decisions have interpreted §315(e)(1) narrowly and have recognized many circumstances where IPR arguments do not give rise to estoppel. One recent decision out of the Northern District of California—Verinata Health v. Ariosa Diagnostics, Case No. 12-cv-05501 (N.D. Cal., Jan. 19, 2017)—represents an exception to this general trend. Verinata held that §315(e)(1) can, in certain circumstances, apply to invalidity grounds included in an IPR petition that the Patent Trial and Appeal Board (PTAB) determined to be redundant and did not institute and carry through to a final written decision.
To help put Verinata in context, a summary of the state of the law regarding IPR estoppel prior to the decision follows.
