A Blog About Intellectual Property Litigation and the District of Delaware


Entries for tag: Estoppel

The law is littered with reasonable people, and none of them do us much good. We have the reasonable person exercising ordinary caution (negligence). There's the reasonable person who attaches importance to the existence or nonexistence of a fact in determining his choice of action (materiality). Relevant to this blog post, and pictured below, we have the "skilled researcher conducting a diligent search" (estoppel).

Cookie the Pom, Unsplash

For those who haven't encountered this one in a while, this hypothetical skilled researcher is the measuring stick we use to determine whether a given reference could have reasonable been raised in an IPR and thus, whether an accused infringer is estopped from raising it in the district court.

As measuring …

Split
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 ...

PTAB trailhead
PTAB trailhead Joshua Sukoff, Unsplash

During some research the other day, I came across the below order that Judge Noreika issued last summer.

A defendant had moved in limine to exclude three of the four asserted claims of a patent from trial, after it prevailed on those claims in an IPR. Easy motion, right?

No. Judge Noreika held that, under Federal Circuit precedent, collateral estoppel does not prevent plaintiff from asserting those claims at trial until the decision is final. And the decision is not final until the appeal is exhausted:

Federal Circuit case law suggests that an IPR decision does not have preclusive effect until that decision is either affirmed or the parties waive their appeal …

Stop Sign
Luke van Zyl, Unsplash

There are certain situations that come up over and over in patent cases. One of them is that a plaintiff will bring identical infringement suits against multiple defendants, and one of those defendants will then file an IPR or CBM proceeding before the patent office attacking the validity of the patents.

Under the America Invents Act, the filing party and any real party in interest are subject to estoppel. But unrelated defendants are not. The filing party will often move to stay the district court litigation. Generally speaking, parties with an instituted IPR or CBM review of all patents-in-suit often have pretty good chances of getting a stay.

So what happens when the defendants in …

Sierra Nevada Mountains
Sierra Nevada Mountains Alistair Corden, Unsplash

The defendant in M2M Solutions LLC v. Sierra Wireless America, Inc., C.A. No. 14-1102-RGA (D. Del.), argued that the PTAB's previous invalidation of several claims of the plaintiff's patents in an IPR meant that the plaintiffs were collaterally estopped from asserting the validity of the remaining claims—the claims that were not invalidated—at the district court.

Defendant argued that:

  • The Federal Circuit has held that collateral estoppel applies to IPR proceedings generally;
  • The Supreme Court has held that agency decisions may have preclusive effects during later court proceedings; and
  • The Federal Circuit has extended collateral estoppel effects to unajudicated claims when there were no material differences between those and …

Previous equations for deciding whether to join an existing IPR
Previous equations for deciding whether to join an existing IPR Roman Mager, Unsplash

Today the Federal Circuit held that a party joining an existing IPR is not subject to estoppel on any grounds other than those that were actually raised. See the opinion below.

Before this, a plaintiff could argue that a defendant who joined an in-progress IPR was estopped on any anticipation or obviousness arguments that "reasonably could have [been] raised" in the IPR.

The Court here held, in short, that because a defendant joining an existing IPR is not allowed to add new grounds at all, it cannot be estopped except on those grounds actually raised.

It relied on the Facebook decision we talked about …

Plaintiff Estopped as Nearby District Moves to Overtake
Plaintiff Estopped as Nearby District Moves to Overtake Abed Ismail, Unsplash

Judge Noreika had a rare holding estopping a plaintiff from asserting the lone patent-in-suit patent due to collateral estoppel after trial.

The Court held a five-day bench trial in Biogen Int'l GmbH v. Amneal Pharms. LLC, C.A. No 17-823-MN in December 2019, dealing with a host on invalidity issues, including obviousness, enablement, and written description. The parties completed post-trial briefing in March 2020, and and a final opinion was thus expected in the not-too-distant future.

Unfortunately for Biogen, they also sued a different defendant, Mylan, in the Northern District of West Virginia on the same patent. That case went to trial in February 2020, on the sole …