Clinic Supports Engine Advocacy, Raising Concerns About Patent Doctrine of Assignor Estoppel

As the 2020-21 term at the Supreme Court winds to a close over the coming weeks, we are awaiting a decision in the case, Minerva v. Hologic (Supreme Court Case No. 20-440). The Court heard oral argument in the case on Wednesday, April 21, 2021, and a decision is expected by the end of June. The Cyberlaw Clinic filed an amicus brief in the United States Supreme Court on behalf of Engine Advocacy, challenging the application of assignor estoppel doctrine in patent litigation. This brief expands on arguments made in an earlier brief submitted by Engine and the Clinic,  supporting a petition for certiorari in the case.

The question presented in the case is whether a defendant in a patent infringement action — who assigned a patent or is in privity with an assignor of the patent — is estopped from raising an invalidity defense. Assignor estoppel is particularly important to Engine, a non-profit organization that advocates for startup companies. The brief urges the court to abolish the assignor estoppel doctrine altogether or restrict the doctrine, because it harms innovation, entrepreneurship, and employee mobility.

The doctrine of assignor estoppel was established to prevent inventors from selling an invention for profit by misrepresenting or concealing facts from someone who relies on the misrepresentation. As the brief notes, however, federal judges expanded the doctrine over time to include situations without bad faith. Low-quality patent holders have misused and abused the doctrine to protect patents that are vague, overbroad, claim prior art, or cover inventions that should not be patentable.

The effects are particularly harmful to startups with limited resources, especially those founded by former employees of established corporations in the same market. It is a common practice for employers to require employees to assign their inventions to the company. Under the assignor estoppel doctrine, a former employee who uses prior art to develop a new invention and is sued for infringement by their former employer is left without an invalidity defense. The current application of the assignor estoppel doctrine has the potential to subject startup companies to costly and lengthy litigation.

The amicus brief highlights how established corporations in preceding cases have deployed the doctrine to mask anticompetitive agendas, such as shuttering competing companies, avenging injured feelings, or preventing a startup from hiring away engineers. The brief further argues that the case involving Minerva and Hologic represents the latest effort to broaden assignor estoppel doctrine, without basis in law, and is directly contrary to the core innovative purposes of the patent system. Engine and the Clinic call on the Supreme Court to Court to dismantle a judge-made doctrine that too often facilitates abusive litigation.

Spring 2021 Cyberlaw Clinic student Sarah Rutherford drafted the amicus brief with Clinical Professor Chris Bavitz and Engine’s IP Counsel, Abby Rives. As noted, the brief built on previous work done by former clinic students Ab Henry and Daniel Dalla Vedova, who also worked with Chris and Abby at the cert stage. The Clinic is grateful to have had the opportunity to collaborate with Engine again and hopes that the Supreme Court’s decision reflects the role of startups in our country’s most innovative industries by restoring their right to challenge low-quality patents.

Image US Supreme Court DC.jpg, from Wikimedia Commons, courtesy Flickr user dbking, CC BY 2.0.  

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