Why a Court’s Validity Ruling Does Not Bar Reexamination at the USPTO

Patent owners who win a validity fight in court sometimes assume the question is closed. It is not, at least not at the USPTO. A court and the Office ask different questions under different standards, and a court judgment that a patent is “not invalid” does not prevent the Office from reexamining the same claims.

The rule has a long history and real consequences: claims a court upheld can still be cancelled in ex parte reexamination, and that cancellation can reach back into litigation that has not yet ended.

Different questions, different standards

In litigation, an issued patent is presumed valid under 35 U.S.C. § 282, and an accused infringer must prove invalidity by clear and convincing evidence. If the challenger falls short, the court does not declare the patent valid; it holds that the patent has not been shown to be invalid.

In reexamination, there is no presumption of validity. The examiner decides patentability under a preponderance of the evidence standard and gives claims their broadest reasonable interpretation in light of the specification. Because the patent owner can amend claims in reexamination, the Office reads them more broadly than a court would.

Feature	District court	USPTO reexamination
Presumption of validity	Yes (§ 282)	No
Burden of proof	Clear and convincing evidence	Preponderance of the evidence
Claim construction	Ordinary meaning to a skilled artisan, in light of the record	Broadest reasonable interpretation
Outcome	“Not invalid” or invalid	Claims confirmed, amended or cancelled

Given these differences, a court ruling and an Office decision on the same art can reach different results without either being wrong.

Ethicon v. Quigg: two tracks

In Ethicon, Inc. v. Quigg (Fed. Cir. 1988), the Federal Circuit addressed whether the Office could hold a reexamination in abeyance while related litigation proceeded. The court held that it could not, because reexamination is to be conducted with special dispatch, and it emphasized that the court and the Office proceed separately. Each forum applies its own standards, and neither waits on the other as a matter of law.

In re Swanson: same reference, new question

In re Swanson (Fed. Cir. 2008) addressed reexamination based on a reference that had been considered in earlier litigation, where the court had rejected an invalidity challenge. The patent owner argued that the reference could not raise a substantial new question of patentability because it had already been considered.

The Federal Circuit disagreed. A court’s earlier consideration of a reference under the clear-and-convincing standard does not prevent the Office from finding that the same reference raises a substantial new question under its own standards.

The 2002 amendment to § 303(a)

The threshold for ordering ex parte reexamination is a substantial new question of patentability. Earlier case law had read that requirement to exclude art the Office had already considered. In 2002, Congress amended 35 U.S.C. § 303(a) to provide that the existence of a substantial new question is not precluded by the fact that a patent or printed publication was previously cited by or to the Office or considered by the Office.

The question must still be “new” in the sense that the art is being presented in a new light or for a new purpose; MPEP Chapter 2200 explains the Office’s approach.

Fresenius v. Baxter: effect on pending litigation

Fresenius USA, Inc. v. Baxter International, Inc. (Fed. Cir. 2013) showed how the two tracks can collide. The patent owner had won an infringement judgment upholding validity, and parts of that judgment had been affirmed on appeal. Meanwhile, the Office cancelled the asserted claims in reexamination, and the Federal Circuit affirmed the cancellation.

The court held that because the infringement case was not yet final, including as to remedies, the cancellation applied to it. The patent owner could no longer recover on the cancelled claims. The decision made reexamination outcomes a significant factor for parties in long-running litigation.

What this means today

Accused infringers can pursue validity challenges at the Office in parallel with or after litigation, through reexamination or AIA trials such as inter partes review. AIA trials, unlike ex parte reexamination, carry their own estoppel rules; see estoppel arising from PTAB trials. Patent owners facing reexamination of litigated claims also need to consider whether amendments would create intervening rights, discussed in the article on Marine Polymer v. HemCon.

Key takeaways

• A court finding that a patent is “not invalid” reflects a clear-and-convincing standard and does not bind the USPTO.
• Reexamination uses a preponderance standard and broadest reasonable interpretation, with no presumption of validity.
• Ethicon v. Quigg and In re Swanson confirm that court and Office proceed separately, even on the same reference.
• Section 303(a), as amended in 2002, allows a substantial new question based on art previously considered by the Office.
• Under Fresenius v. Baxter (Fed. Cir. 2013), cancellation in reexamination can defeat a pending infringement case that is not yet final.