Justia Opinion Summary and Annotations

Truckai invented NovaSure to treat abnormal uterine bleeding using a moisture-permeable applicator head to destroy targeted cells. Truckai filed a patent application and assigned the application and future continuation applications, to his company, Novacept. Novacept and its patents and patent applications were acquired by Hologic. Truckai founded Minerva and developed a supposedly improved device to treat abnormal uterine bleeding, using a moisture-impermeable applicator head to remove cells. The Patent and Trademark Office (PTO) issued a patent; the FDA approved the device for sale. Hologic filed a continuation application, seeking to add claims to its NovaSure patent–one claim encompassed applicator heads generally, without regard to whether they are moisture permeable. The PTO issued the altered patent.

Hologic sued Minerva for infringement. Minerva argued that Hologic’s patent was invalid because the new claim did not match the written description. Hologic invoked the assignor estoppel doctrine: Because Truckai had assigned the original application, he and Minerva could not impeach the patent’s validity. The Federal Circuit agreed.

The Supreme Court vacated. Assignor estoppel is a valid defense, based on the need for consistency in business dealings, but applies only when the assignor’s claim of invalidity contradicts explicit or implicit representations made in assigning the patent. Concerns with the assignor taking contradictory positions do not arise when an assignment occurs before an inventor can make a warranty as to specific claims, such as when an employee assigns to his employer patent rights in future inventions; when a later legal development renders irrelevant the warranty given at the time of assignment; and when a post-assignment change in patent claims can remove the rationale for applying assignor estoppel. The Federal Circuit failed to recognize these boundaries, deeming “irrelevant” the question of whether Hologic had expanded the assigned claims. If Hologic’s new claim is materially broader than what Truckai assigned, Truckai could not have warranted its validity.

Annotation

Primary Holding

Supreme Court defines the boundaries of the “assignor estoppel” defense to a claim of patent invalidity.