Infringement Claims Barred by Equitable Estoppel Following Ten-Year Delay in Filing Lawsuit

The court granted defendant's motion for summary judgment that plaintiff's patent infringement claims were barred by equitable estoppel due to its ten-year delay in filing suit and found that defendant was materially prejudiced by plaintiff's silence following its cease-and-desist letter. "In the six years leading up to [plaintiff's] suit, [defendant's] marketing and investment efforts in [the accused product] yielded sales that nearly quadrupled its revenue. Rather than demonstrate that the investment was 'simply a business decision to capitalize on a market opportunity,' as [plaintiff] claims, these facts indicate more strongly that [plaintiff] saw a market opportunity to resuscitate its previously abandoned claims in order to capitalize on [defendant's] stronger revenues. After ten years of failing to follow up on its threat of infringement, [defendant] would be undeniably prejudiced if the Court allowed [plaintiff] to bring forth its claims only after [defendant] made substantial investments in its product."

Akeso Health Sciences, LLC v. Designs for Health, Inc., 2-16-cv-07749 (CACD April 26, 2018, Order) (Otero, USDJ)