Defendant Hewlett Packard filed a Petition for IPR challenging claims of U.S. Patent No. 6,218,930 as invalid in view of two prior art references. On the same day Defendant requested joinder with an earlier filed IPR that challenged the same claims of the ‘930 patent as invalid over four references (including the two raised in Defendant’s own petition).

During the District Court proceeding the Defendant sought to challenge the validity of claims over prior art references presented in the two IPR Petitions, but in different combinations than those presented in the two IPR Petitions. The Plaintiff argued that Defendant was estopped from presenting these combinations under § 315(e) because Defendant “could have reasonably raised them in its IPR petition.” Slip Op. at 5.

The Eastern District of Texas agreed with the Plaintiff and excluded arguments based on prior art that was raised before the PTAB or reasonably could have been raised, regardless of whether the specific combination of prior art was actually raised. The Court found that “[u]nder §315(e)(2), IPR estoppel applies to non-petitioned grounds (grounds that a party failed to raise in an IPR, but reasonably could have).” And went on to note that Defendant’s “argument—that it would not be estopped from asserting the [non-petitioned] combinations at trial only if it had raised them during its IPR petition—would render the reasonably could have raised language nearly meaningless.” Slip Op. at 8 (citations and quotations omitted).

This decision strengthens the estoppel provisions under §315(e). It also demonstrates that Petitioners must not only use the best combination of prior art in their own petitions but, before seeking joinder, must also confirm that earlier filed petitions use the best combination of prior art as other combinations of that prior art will not be available in a District Court proceeding.

Network-1 Techs., Inc. v. Alcatel-Lucent USA, Inc., et al, Case 6:11-cv-492-RWS-KNM (E.D. Tex. Sept. 25, 2017)