A Blog About Intellectual Property Litigation and the District of Delaware

Entries for tag: IPR Estoppel

Split Cup
Tania Melnyczuk, Unsplash

Judge Fallon issued an order yesterday recognizing the split in the district court on how the judges handle IPR estoppel—specifically the question of whether IPR estoppel may apply to prior art products that are cumulative of patents or publications that could have been raised in the IPR:

ORAL ORDER . . . IT IS ORDERED that Plaintiff's motion to strike Defendant's amended invalidity contentions based on IPR estoppel is DENIED without prejudice. The parties dispute whether IPR estoppel should apply to Defendant's invalidity theories based on prior art systems, products, and/or knowledge. Under 35 U.S.C. § 315(e)(2), Defendant is barred from asserting an invalidity defense based on "any ground that [Defendant] raised or reasonably could …

Bannon Morrissy, Unsplash

IPR estoppel can be kind of terrifying as an accused infringer in a patent action. The statute says that an accused infringer may not assert invalidity on a ground that it could have raised in the IPR; but you can't raise product prior art, so product prior art should be safe, right?

Nope. Courts have sometimes held that product prior art may still be estopped, if there is patent or written prior art that is sufficiently similar. See, e.g., Wasica Fin. GmbH v. Schrader Int’l, 432 F. Supp. 3d 448, 453 (D. Del. 2020) (holding defendant estopped from asserting product art where “all the relevant features” of the art were in a printed publication that could have been raised in an IPR).

As Judge Stark notes in Wasica, courts have gone both ways on this, with some estopping arguments based on product art where similar written or patent art could have been raised in an IPR, and others permitting those arguments.

On Friday, Judge Noreika chose a side in this split: no estoppel for prior art products ...