In the holding below, Judge Burke found that, under Pennypack, producing documents just over two months before trial was sufficient to provide time for "Defendants to be able to appropriately respond to Plaintiffs' expert's related position."
This is a shorter timeline than typically comes up. For example, Judge Burke has previously struck late-produced material where there were six months remaining before trial, although in that case the other Pennypack factors also played a role.
The facts here were not terrible for defendants. The documents had been produced by individual defendants in a set of related cases. According to the plaintiff, the expert reports at issue used the documents from various defendants to respond to arguments from those defendants, although …
Judge Andrews recently granted a motion in limine precluding a party from presenting expert opinions that were not disclosed until the expert's deposition -- without analyzing the Pennypack factors.
The correct procedure for challenging a late disclosure of theories or evidence has long been a matter of some debate in Delaware. There are cases suggesting that the party seeking to update its contentions should move for leave to do.
More commonly, a party will simply serve updated contentions or expert reports that the opposing party moves to strike. Regardless, the motions are generally analyzed under the demanding Pennypack factors, with the usual result that the …
It can be tough to get late-produced theories or evidence excluded in Delaware, because the Court must apply the permissive Pennypack factors that typically favor admission.
The factors include prejudice, ability to cure any prejudice, disruption of trial, and bad faith/willfulness.
But lately, the Court seems to be granting more motions to strike such theories. Today, Judge Andrews granted a motion to strike a late DOE theory offered for the first time in a reply report.
Judge Andrews Isn't Messing Around
He shot down the Pennypack factors in four short and to-the point paragraphs.
As to the first factor, he foundprejudice because admission of a late theory requires …
For years now I've been working on a double-dutch rhyme for the Pennypack factors. A Miss Merry-Mack for elderly nerds, if you will. It shall be my crowning achievement as a Delaware lawyer, and the work that I shall be remembered for.
AI-Generated, displayed with permission
But until that Glorious work is unveiled at the 2038 Bench and Bar conference, I can present you with just another Pennypack opinion for your portfolio. This one follows the recent trend of a slightly harsher application of the factors.
The Plaintiff in Agilent Techs., Inc. v. Axion BioSystems, Inc., C.A. No. 23-198-CJB, D.I. 456 (D. Del. Nov. 25, 2025) had responded to an interrogatory asking for which elements were not …
As a young lad, analytical chemistry was my jam. I liked big cool machines with lasers and flames. I liked dissolving things in acid. I liked anything that gave off a swirly gas when heated.
For that reason, I have a special empathy for the plaintiffs in Harmony Biosciences, LLC v. Lupin Ltd., C.A. No. 23-1286-JLH-SRF (D. Del. Oct. 27, 2025), and their poor, overworked experts.
The patent there was for a specific crystalline form of a drug. Typically, you would figure out this form via X-ray diffraction (XRD), which involves shooting X-rays at a crystal (typically powdered) from different angles. Via science too involved to get into here, you get a series …
This is not the level of disclosure at issue here.AI-Generated, displayed with permission
Most readers who are patent litigators will know this already, but a "claim chart" is a table with two columns. The column on the left lists claim elements, and and the column on the right lists the portions of something—typically a product, system, or disclosure—that meets the elements on the right.
The chart shows the reader how the thing (whatever it may be) meets the elements of a claim or claims.
Detailed claim charts sometimes include figures with arrows pointing to the relevant claim elements, quotes of relevant text (if applicable), and/or a narrative description of how the cited material meets the element.
I am pleased to announce that, starting with Andrew's next post, we will be pivoting to a new format. No longer will we be analyzing the developments in IP law with mere written words. Instead, we will be creating Schoolhouse Rock style musical videos. Andrew's surprisingly moving singing voice will be accompanied by my own interpretive dance—leading you through the intricacies of the days' cases like a bee describing the way to honey.
This is perhaps my favorite picture I've used on the blogAI-Generated, displayed with permission
The subject of today's post, CosmoKey Solutions GmbH & Co. KG v. Duo Security, Inc., C.A. No. 18-1477-CFC-CJB, D.I. 413 (D. Del. Feb. 7, 2025) will also be the subject of our first song, "Sanction Sanctuary."
The title comes from the plaintiff's motion for sanctions -- unusual in the district outside of the Pennypack context. The issue there was that the defendant had produced almost all of its documents after the substantial completion deadline, resulting in extra work for the plaintiff, who sought fees as compensation. The defendant argued that the late production was not sanctionable because it was caused in large part by an error in their document collection that had initially missed all documents before 2018.
As an old dog, I'm always excited to learn a new trick. For instance here is me being taught to fetch:
Contact me for the full series of videos wherein, after many weeks of simply throwing the ball on the ground for me to pick up, she throws it right back to me.Bellini, displayed with permission
As a lawyer, this often takes the form of some new novel argument that I might want to try out myself. Sometimes, however, a new trick turns out to be particularly ill-fated.
The defendant in Bausch & Lomb Incorporated et al v. SBH Holdings LLC, C.A. No 20-1463-GBW-CJB (D.I. 250 (D. Del. Feb. 5, 2025) (Oral Order), moved for summary judgment under of no infringement under the DOE based on the disclosure-dedication doctrine. The problem was that plaintiff had served a rog asking for defendant's non-infringement contentions, and the defendant had not disclosed this theory. So, the plaintiff moved to strike the argument.
The defendant countered that, since disclosure-dedication is based upon the specification itself (which plaintiff obviously had), and is decided by the Court as a matter of law, there was no need to disclose the theory in response to a rog (this is the bit I hadn't seen before).
Judge Burke, however, disagreed, and granted the motion to strike:
Defendant’s arguments have no merit. Fed. R. Civ. P. 33(b)(2) says that a party must respond to an interrogatory within 30 days, and Fed. R. Civ. P. 26(e) says that a party must supplement a response to an interrogatory in a timely fashion if, inter alia, it learns that a prior disclosure is incomplete or incorrect. There is no exception to these rules of the kind Defendant suggests. Just like every other party in a patent case, Defendant had to timely respond to contention interrogatories—a means of discovery that plays an important narrowing role in patent litigation. Defendant’s view to the contrary would, if permitted, wrongly allow a party—and not the Federal Rules of Civil Procedure—to determine whether it has to follow the discovery rules in a patent case, and to dictate what theories it does and doesn’t have to disclose. For all of these reasons, there can be no doubt that Defendant’s incredibly late disclosure of the DD theory in its summary judgment briefing (filed in September 2024) amounts to an untimely disclosure under Rule 26(e).
Id. (internal citations omitted).
The Court then went on to analyze the issue under Pennypack, finding that each of the factors were neutral or supported exclusion.
I'm a baker. I was born of flour and heat and fermented in this big jar we call life. My original starter, Yeasty Boy, has sired many children that live lives of plenty. His grandchild, breAD-Rock, sits upon my counter as I type, growing fat on apple peels.
AI-Generated, displayed with permission
One of the first lessons of baking is that some ingredients can be modified or omitted without any real worry. You trade rosemary for thyme in your focaccia and everything's honky dory. On the other hand, if you switch the strong bread flour to whole wheat, you have crossed a moral line from which there may be no return. Some ingredients are simply more important, and some substitutions …
Yes, this is yet another Pennypack post. I can't resist. It's a tough-to-apply standard that impacts many cases (patent and otherwise). And it can sometimes seem to reward bad behavior by litigants, even—maybe especially—when applied as written.
But not this time! In Prolitec Inc. v. ScentAir Technology, LLC, C.A. No. 20-984-WCB (D. Del. Oct. 2, 2024), the patentee produced documents about a pre-priority-date sale of prior art after fact discovery closed and just five days before opening reports.
Unsurprisingly, the other side's opening expert report five days later did not include invalidity allegations about this sale.
This blog is for general informational purposes. It is not an offer to perform legal services, and should not be considered a substitute for legal advice. Nothing in this blog should be construed as forming an attorney-client relationship. If you have legal questions, please consult counsel in your jurisdiction.
