Earlier this year, the Federal Circuit held that statements made by patentees in an inter partes review (IPR) can constitute prosecution disclaimer. Aylus Networks, Inc. v. Apple Inc., No. 2016-1599 (Fed. Cir. May 11, 2017). In a recent district court decision, this new rule was given effect. Patent Owner’s statements in a preliminary response were held to amount to disavowal of claim scope sufficient to support a grant of summary judgment of non-infringement. Huwaei Technologies filed suit in the Eastern District of Texas, alleging that T-Mobile’s 3G network infringed Huawei’s patent. Report and Recommendation, Huawei Technologies Co. LTD v. T-Mobile US, Inc, et al., Case No. 2:16-CV-00052-JRG-RSP (EDTX Sep. 9, 2017). After suit was filed, Nokia petitioned for inter partes review of the claims of the patent asserted against T-Mobile. Id at 2. According to the R&R, in its preliminary response to the petition, Huawei argued that the prior art, which was a technical report describing the relevant 3GPP standard, failed to show a recited claim element – preserving the “PDP context.” Id. at 4.

In the district court litigation, Huawei argued that its patent is essential to the same 3GPP TS 23.060 standard, as described in the prior art technical report. Id at 4. However, according to the district court findings, the standard does not preserve the PDP context but rather marks it invalid. Id. at 8. And, based on the arguments made during the related inter partes review, “[a]ccording to Huawei’s statements, it is impossible to preserve the PDP context after it has been marked invalid.” Id. Thus, the court determined that regardless of its technical accuracy, Huawei had disavowed its claim scope by making representations to the public in the inter partes review proceeding. The court determined that T-Mobile could not infringe the patent and granted partial summary judgment of non-infringement. Id. This decision reinforces the tenet that litigation and IPR counsel must coordinate their efforts to avoid the possibility of practical estoppel.