According to a recent district court opinion, a party may waive its right to assert infringement on claims that it voluntarily agrees to give up (e.g., by abandoning the claims). Such a waiver will be enforced as an equitable estoppel defense for the alleged infringer. To establish a waiver, there must be a clear and unequivocal act of a party showing such a purpose.

In Snyders Heart Valve LLC v. St. Jude Medical S.C., Inc. et al Case No. 0:2018cv02030 (D. Minn. March 23, 2021), the District Court reviewed the proceedings between the parties to determine whether Snyders waived its right to assert seven patent claims revived by the Federal Circuit on appeal of an inter partes review ("IPR") by the Patent Trial and Appeals Board ("PTAB"). Snyders initially filed a Complaint in 2016, asserting that St. Jude is infringing U.S. Patent No. 6,821,297 ("the '297 Patent") and U.S. Patent No. 6,540,782 ("the '782 Patent"), which both relate to devices for artificial heart valves. In turn, St. Jude filed four IPR petitions challenging the patentability of the asserted claims, which culminated in the PTAB concluding that claims 1, 2, 6, and 8 of the '782 Patent were unpatentable and that claims 1–3, 8–9, 22–23, 31–35, 37–39, and 45 of the '297 Patent were unpatentable. The PTAB's decisions were later reversed on appeal to the Federal Circuit, and the seven patent claims at issue here were revived.

In the instant District Court proceeding, the central issue was whether an offer made by Snyders's after the PTAB decisions and before the appeal was filed, in which Snyders agreed to drop the invalidated claims if St. Jude agreed to proceed to trial only on the confirmed claims, constituted a clear and unequivocal waiver. Snyders argued it did not waive its right to enforce the now-revived claims for two reasons. First, Snyders contended that the offer was conditional on St. Jude's agreement to proceed to trial on the confirmed claims, and that this condition was not met. This is because rather than proceeding to trial, St. Jude filed a motion to stay, which then led to the parties filing cross-appeals of the PTAB decisions to the Federal Circuit. Second, Snyders argued that unlike other claims that it had abandoned through a formal motion earlier in this case, no such action was taken on the disputed claims. St. Jude took the position that Snyders had dropped the now-revived patent claims in an attempt to improve its position in opposing St. Jude's motion to stay following the IPR decisions. In addition, St. Jude contended that the conditions of the offer were met because the case proceeded toward trial since the Court denied St. Jude's motion to stay in large part, and the case proceeded toward trial.

Upon review of the proceedings, the Court found that Synders's offer did not amount to a clear and unequivocal waiver. Specifically, the Court concluded that each instance in which Snyders offered to drop the seven claims was conditional, and that the conditions were not met because St. Jude appealed the IPR decision rather than proceeding to trial. Additionally, the Court found that although the pretrial matters were permitted to continue following the denial of St. Jude's motion to stay, the case did not proceed to  trial, and had merely proceeded toward  trial. The Court also found that the Courts' statements encouraging Snyders to provide a covenant not to sue, and Snyders statement on a Joint Memo that "There are no claims remaining for the '297 Patent," were both ambiguous and did not support a finding of waiver. In sum, the Court held that none of Snyders's representations amounted to a clear and unequivocal waiver of the now-revived claims.

This decision demonstrates, in part, that a conditional offer to drop claims is unlikely to meet the threshold of being a clear and unequivocal waiver unless the receiving party unambiguously accepts the conditions of the offer.

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