Fed Circuit rejects Minerva patent invalidation bid
Hologic patent invented by Minerva’s founder cannot be invalidated | Patent in dispute concerns device used to treat uterine bleeding | US Court of Appeals.
The US Court of Appeals for the Federal Circuit has concluded that Minerva Surgical can’t invalidate an Hologic patent for which Minerva's founder was the inventor.
On remand from the US Supreme Court, the precedential decision—handed down yesterday, August 11—rejected Minerva’s bid to invalidate a patent covering an endometrial ablation device used to treat abnormal uterine bleeding by destroying targeted cells in the lining of the uterus.
The patent at issue was invented by Csaba Truckai, who assigned the patent to Novacept in 2004. Later that same year, Hologic acquired Novacept and the patent. Hologic subsequently obtained a continuation to the patent.
Then, in 2008, Truckai (who founded Minerva) patented a new treatment and assigned it to Minerva, prompting Hologic to sue Minerva for infringement.
In response, Minerva asserted invalidity defences and claimed Hologic had broadened the scope of the patent beyond what was initially claimed by Truckai.
Estoppel argument
Hologic moved for summary judgment, arguing that the doctrine of assignor estoppel bars Minerva from challenging the validity of the ‘348 patent claims in district court. The district court agreed and the Federal Circuit then affirmed-in-part the decision.
However, in June last year, the Supreme Court narrowed the scope of the doctrine of assignor estoppel and vacated the Federal Circuit's holding, which affirmed the district court’s summary judgment of no invalidity for claim 1 of US patent number 9,095,348.
For more than a century before this ruling, the doctrine 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.
According to the Supreme Court, assignor estoppel “applies only when an inventor says one thing (explicitly or implicitly) in assigning a patent and the opposite in litigating against the patent’s owner”.
On remand, the Federal Circuit was tasked with considering whether the newly limited assignor estoppel doctrine precluded Minerva from challenging the validity of claim 1.
The court determined that claim 1 of the continuation patent is not “materially broader” than the claims assigned to Hologic in the original patent so assignor estoppel applied, barring Minerva from challenging the validity of the claim.
Additionally, the court reinstated its earlier judgment, affirming the district court’s denial of Hologic’s motions for a permanent injunction, enhanced damages, and ongoing royalties for infringement of another asserted patent.
It also reinstated its affirmation of the district court’s summary judgment of infringement of claim 1 of the ‘348 patent, and the court’s denial of Hologic’s requests for supplemental damages and for increased and enhanced supplemental damages.
Finally, the Federal Circuit reinstated its decision to vacate the district court’s award of pre-and post-judgment interest on the supplemental damages award, and remanded this with instructions to calculate the interest award.
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