Processing All Things Federal Circuit
August 16, 2022 - Last Week in the Federal Circuit

Last Week In The Federal Circuit (August 8 – August 12): Taking A Round Trip On The Assignor Estoppel Express

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For most of us, we’re stuck in the August heat, on delayed European vacations, or hopefully just hanging out at the beach. But for the Court it still was work as usual, including a return trip to the Federal Circuit for the defendant in Minerva. Below we provide our usual weekly statistics and a detailed discussion of our case of the week—our highly subjective selection based on whatever case piqued our interest.

Precedential opinions: 7

Non-precedential opinions: 7

Rule 36: 1

Longest pending case from argument: In re: McDonald, No. 21-1697 (153 days)

Shortest (non-Rule 36) pending case from argument: Hirsch v. US, No. 21-2163 (34 days)

Case of the week: Hologic, Inc. v. Minerva Surgical, Inc., No. 19-2054

Panel: Judges Stoll, Clevenger, and Wallach, with Judge Stoll writing the opinion

You should read this case if: you want to know how the Federal Circuit will treat assignor estoppel post-Minerva

You have to feel a little sorry for a party that beats the incredible odds of getting Supreme Court review only to end up with the same result. That’s what happened in our case of the week.

Unless you’ve been living under a rock (or the proverbial equivalent of a rock in patent-land—the MPEP maybe), you’re no doubt aware of one of the few relatively recent Supreme Court patent cases: 

Minerva Surgical, Inc. v. Hologic, Inc. (And once again, here’s where a few readers shed a tear for what could have been in American Axle.) As a recap, the Supreme Court granted cert to decide whether the doctrine of assignor estoppel found any support in patent law. Assignor estoppel precludes an assignor of a patent from later challenging that patent’s validity. At least initially, smart money was on the “no” side, as nothing in the U.S. Code expressly provides for assignor estoppel, and this is supposedly a textualist Supreme Court.

But this is one of those cases where Vegas got burned. Assignor estoppel survived. The reason why: at least in patent-land, the Supreme Court likes to follow its precedent—especially really old precedent. (Because what makes more sense when talking about innovation and new technology than looking back to really old cases—like purported inventions of using flowing water to clean manure in barns, right?) The doctrine of assignor estoppel had that in spades. Not only was there century old precedent from the Supreme Court, but there were even cases from the other side of the Atlantic—all providing support for assignor estoppel. The Supreme Court held that the doctrine was designed to prevent an inventor from first selling a patent and then contending that the thing sold is worthless. Of course, it wasn’t all great for the doctrine; the Supreme Court said the Federal Circuit took the doctrine too far. Assignor estoppel could be no broader than whatever explicit or implicit representations the assignor made about the patent’s validity. It then left it up to the Federal Circuit to address the doctrine’s application on remand.

So on remand the Federal Circuit did just that. Here, the challenged asserted claim traced back, through a series of continuation and divisional applications, to an application that had been assigned. The Court addressed whether that asserted claim was materially broader than the claims that had been assigned. After all, if the later-issued asserted claim was broader than the assigned ones, the assignor could not have warranted as to the broader claim’s validity.

What seems like a relatively straightforward claim construction issue—is one claim (the asserted one) basically no broader than another (the assigned ones)—was complicated by the fact that the broadest (at least for our purposes) assigned claim (claim 31) had been cancelled prior to the assignment. That led to the metaphysical question of whether an assignor could vouch for the validity of a claim that had been cancelled. At least on these facts, the answer was yes. Without getting into too much nitty gritty, the basic issue was that the examiner decided to reject the application as improperly claiming two distinct inventions, so the applicant elected to prosecute the claims of one invention but not the other. But in not prosecuting the other invention (including claim 31) the applicant requested that the examiner cancel those claims “without prejudice.” Given that history as a whole, the Court said that the cancellation “says nothing, implicitly or explicitly, about the patentability of claim 31.” The applicant remained free to prosecute claim 31 in a divisional application, and that right travelled with the assignment. As such, even though claim 31 had been cancelled, the assignor still could—and here did—represent that the subject matter of the claim was not invalid. (Lest anyone assume this means that any assigned cancelled claim could be represented as not invalid, the Court made clear in a footnote that its holding was “limited to the facts of this case.”)

Having determined that the assignor had warranted to the validity of the cancelled claim, the Court then determined whether the asserted claim was materially broader than the assigned ones. That issue, the Court explained, was a question of claim construction. And applying those principles, it concluded that the asserted and assigned claims were not materially different in breadth. With that, the Court once again affirmed the district court’s assignor estoppel decision—leaving the defendant where it began on its journey through the federal appellate process.