Breaking: SCOTUS says inventors can challenge their patents, but imposes limits
The US Supreme Court has upheld the doctrine of assignor estoppel in a dispute between Minerva and Hologic but has narrowed its scope. SCOTUS handed down the decision today, June 29, in a fractured 5-4 opinion that effectively bars an inventor from challenging their own patents, and imposing new limits when the principle of assignor estoppel can be invoked.
The dispute revolved around whether inventors may assert patent invalidity as a defence against later infringement.
For more than a century, the assignor estoppel doctrine has held that an inventor who assigns patent rights to someone else cannot later challenge the validity of that patent in a subsequent dispute with the patent's new owner. Today's ruling appears to narrow when that doctrine can be applied.
A splintered opinion
In April 2020, a US Court of Appeals for Federal Circuit ruling affirmed-in-part an earlier decision by the US District Court for the District of Delaware, claiming that assignor estoppel barred Minerva from asserting invalidity of assigned patents after Hologic had sued Minerva for infringement.
Today, Justice Elena Kagan delivered the opinion of the court and was joined by Chief Justice John Roberts and Justices Gerald Breyer, Sonia Sotomayor, and Brett Kavanaugh. Justices Samuel Alito and Amy Barrett both wrote separately to dissent. Justices Clarence Thomas and Neil Gorsuch joined Barrett's dissent.
The majority justices determined that while there are valid uses of the assignor estoppel doctrine and the Federal Circuit was right to uphold it in this particular case, the lower court failed to recognise the doctrine’s limits.
In 1998, the inventor of the patents in dispute, Csaba Truckai, was granted two patents for uterine bleeding treatments, US patent numbers 6,872,183 and 9,095,348. He assigned the patents to Novacept in 2004. Later that same year, Hologic acquired Novacept and the ‘183 and ‘348 patents.
Truckai meanwhile patented a new treatment in 2008 and assigned it to Minerva, leading Hologic to sue Minerva. Hologic argued that the new device infringed on the Novacept patents, which were now owned by Hologic.
Earlier this year, the US Supreme Court had agreed to hear Minerva Surgical v Hologic to consider whether an inventor or those in privity with the inventor may assert patent invalidity as a defence against a patent infringement suit for the inventor’s patent.
Look out for more reaction, comment and analysis to this decision on LSIPR throughout the week.
