Minerva Surgical, Inc. v. Hologic, Inc.


Question(s) Presented

“[W]hether a defendant in a patent infringement action who assigned the patent, or is in privity with an assignor of the patent, may have a defense of invalidity heard on the merits.”


“In Westinghouse Elec. & Mfg. Co. v. Formica Insulation Co., 266 U. S. 342, 349 (1924), this Court approved the ‘well settled’ patent-law doctrine of ‘assignor estoppel.’ That doctrine, rooted in an idea of fair dealing, limits an inventor’s ability to assign a patent to another for value and later contend in litigation that the patent is invalid. The question presented here is whether to discard this century-old form of estoppel. Continuing to see value in the doctrine, we decline to do so. But in upholding assignor estoppel, we clarify that it reaches only so far as the equitable principle long understood to lie at its core. The doctrine applies when, but only when, the assignor’s claim of invalidity contradicts explicit or implicit representations he made in assigning the patent.”

Proceedings and Orders
October 14, 2020
Blanket Consent filed by Petitioner, Minerva Surgical, Inc.
November 24, 2020
DISTRIBUTED for Conference of 12/11/2020.
November 24, 2020
December 9, 2020
DISTRIBUTED for Conference of 1/8/2021.
January 8, 2021
Petition GRANTED.
February 22, 2021
February 22, 2021
Consent to the filing of amicus briefs received from counsel for Minerva Surgical, Inc. submitted.
March 12, 2021
SET FOR ARGUMENT on Wednesday, April 21, 2021.
March 15, 2021
Record requested.
March 30, 2021
April 5, 2021
Motion of the Acting Solicitor General for leave to participate in oral argument as amicus curiae and for divided argument GRANTED.
June 29, 2021
Judgment VACATED and case REMANDED. Kagan, J., delivered the opinion of the Court, in which Roberts, C. J., and Breyer, Sotomayor, and Kavanaugh, JJ., joined. Alito, J., filed a dissenting opinion. Barrett, J., filed a dissenting opinion, in which Thomas and Gorsuch, JJ., joined.
August 2, 2021