Last week, Judge Bryson ruled on a motion in limine where an accused infringer sought to strike the patentee's alleged "new theory" of validity just before trial or, in the alternative, for a permission to raise a new claim construction regarding that theory.
The Court ultimately denied the motion in limine because the accused infringer was on notice of the theory, but granted its alternative motion for permission to raise a new claim construction position regarding the theory, citing O2 Micro.
The Accused Infringer Was On Notice of the Issue
The Court easily denied the motion to strike, finding seven different ways that the accused infringer either was or should have been aware of the theory earlier:
- The "new" theory is that the claims lack a "physical stability" limitation, but there is no such language in the claims.
- In a prior case that the parties were familiar with, the Court held that a claim in a related patent that lacked the language likewise lacked the limitation.
- The patentee's rebuttal report noted that similar claims of a related patent lacked this limitation because they lacked the language.
- The accused infringer's own expert agreed.
- The patentee's expert also noted the language was missing from the asserted claims.
- The accused infringer asked questions about this limitation (and its proposed construction) at the deposition of the patentee's expert.
- The patentee's expert took the same position in a prior case.
In light of all of these things, the Court found that the patentee was on notice:
Under these circumstances, [accused infringer] Azurity was plainly put on notice that [patentee] Heron did not agree with Azurity’s position that the claims that did not include an express “physical stability” limitation should be construed to include such a limitation anyway. Indeed, it appears that, at least as of the time he submitted his reply report, Dr. Amiji agreed with that position. Therefore, Azurity has not made a persuasive showing that it was misled into believing that Heron would not take the position that those claims that did not include such a limitation.
. . .
I reject Azurity’s contention that Heron violated a duty to advise Azurity that Heron was taking the position that the asserted claims of the ’254 and ’255 patents should be read not to require any particular level of emulsion stability, and that Heron should be barred from taking that position at trial.
Heron Therapeutics, Inc. v. Azurity Pharmaceuticals, Inc., C.A. No. 24-830-WCB, at 4 (D. Del. Oct. 29, 2025).
The Court noted that the accused infringer had failed to identify any rule requiring the patentee to "disclose" that it's claims lacked a limitation that simply wasn't present in the claims:
Although Azurity contends that Heron failed to disclose, in a timely fashion, its position that the claims lacking an express stability limitation do not require proof of stability, it is not clear when, according to Azurity, Heron should have made such a disclosure. Azurity provides general references to the Federal Rules of Civil Procedure and the Scheduling Order in this case in support of its failure-to-disclose argument. But it is not apparent why it is necessary for a party to disclose its “theory” that a claim that lacks an express requirement of physical stability does not require proof of physical stability.
Id. at 4-5.
The Court also held that the accused infringer should have raised its claim construction position earlier:
To the extent that Azurity’s position is that the terms “injectable emulsion” and “injectable pharmaceutical emulsion” in the ’254 and ’255 patents must be construed to include a requirement of stability, that is an issue that Azurity should have raised at an earlier point in the proceedings, particularly in light of the fact that I took a contrary view on that issue in my opinion in the Fresenius case.
Id. at 5.
Despite Notice of the Theory, the Court Found No Waiver of the Related Claim Construction Position
The accused infringer asked, in the alternative, for the Court to permit it to present evidence regarding construction of the term during the bench trial.
Interestingly, despite holding that the accused infringer should have raised this earlier, the Court permitted it to present its arguments:
Heron opposes Azurity’s request, arguing that Azurity should have raised the claim construction issue much earlier and that Heron would be prejudiced if Azurity were allowed to raise this issue at this late hour. I disagree. Although Azurity should have recognized the issue earlier, it was not so prominent a part of the pretrial proceedings that Azurity should be charged with waiving its right to raise a potentially critical claim construction issue. It is not unusual for a previously unrecognized claim construction issue to arise late in pretrial proceedings or even during trial, and when it does, it is ordinarily the duty of the court to decide the issue. See O2 Micro Int'l Ltd v. Beyond Innovation Tech. Co., 521 F.3d 1351, 1362 (Fed. Cir. 2008) (“When the parties [present] a fundamental dispute regarding the scope of a claim term, it is the court’s duty to resolve it.”). If this claim construction issue is not resolved conclusively now, it will continue to hover over the case, perhaps even into any appeal that may be taken from the judgment. Accordingly, I will address the issue, even though it has been raised by Azurity for the first time at a late stage in the proceedings.
Id. at 8. The Court relied both on O2 Micro and on the practical problem that, if it didn't resolve the dispute, it would linger over the remainder of the case and could come up on appeal.
Does O2 Micro Make It Impossible to Waive a Claim Construction Position? No—But It May Raise the Bar
O2 Micro involved a situation where the Court had declined to resolve the parties' dispute over the scope of a claim limitation, instead holding that the term "needs no construction" because it has a "well-understood definition." O2 Micro Int'l Ltd. v. Beyond Innovation Tech. Co., 521 F.3d 1351, 1361 (Fed. Cir. 2008).
That opinion also included discussion of whether the party had waived its right to raise the issue on appeal, or its arguments in support of its construction, by not adequately raising them below. Id. at 1359-1360.
But O2 Micro did not involve a situation where the district court had held that a party had waived or forfeited its right to a certain construction, and where the Court had chose the opposing party's construction. We've posted about how the Court has still found waiver of claim construction positions despite O2 Micro (and also about how O2 Micro only applies if the dispute goes to the scope of the claim term).
In its opinion last week in Heron, Judge Bryson recognized that it is possible for a party to waive a claim construction position. Heron, at 8 ("the [claim construction] issue . . . was not so prominent a part of the pretrial proceedings that Azurity should be charged with waiving its right to raise [it]").
Nonetheless, in support of its finding of no waiver, the Court cited O2 Micro and its language about the importance of the Court resolving claim construction disputes. That suggests that while it is still possible to waive claim construction issues, Judge Bryson may view O2 Micro as supporting the application of a higher bar for waiver than would otherwise apply.
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