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 from Minnesota. Home of the noble loon, and dainty ladyslipper. It is a harsh place. I have read in books of lands where a person's word is all they have -- a sacred thing that must be protected at all costs. To barter it away is to invite the most dire peril.
I wasn't really using it much anyway...AI-Generated, displayed with permission
Minnesota is not such a place. The winds are fickle there, and everyone understands that most commitments are contingent upon a (sometimes unlikely) confluence of fortuitous occurrences. If you way, I'll visit Gramma this weekend, there's an implied "if it's not too cold." If you say "I'll bring the cheeseburger soup" it's understood that you …
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.
A perennial question in disputes about late disclosures is whether the demandingFRCP 16 "good cause" standard applies, which hinges on diligence, or whether the more forgivingPennypack factors apply.
When it comes to case narrowing, there seems to be a building trend that the good cause standard applies, not the Pennypack factors. We've seen that multipletimes when it comes to a plaintiff's decision to drop claims, and on Wednesday, Judge Burke issued a detailed opinion finding that good cause is likewise required to revise a defendant's election of prior art references.
In State Farm Mutual Automobile v. Amazon.com, Inc., C.A. No. 22-1447-CJB (D. Del.), the Court ordered the defendant to cut …
I hope the Third Circuit one day revisits the Pennypack factors, which are what it directs the lower courts to apply to determine whether late disclosures are subject to sanctions such as preclusion.
The factors can be lenient on parties that are very late in disclosing critical facts. Pennypack sets up a system where, oddly, the more critical the late-disclosed fact is, the later the party can be, and the less likely it is to be excluded. Isn't that backwards?
In practice, the factors often seem to turn on whether there is incurable prejudice, and that can be hard to establish. But a rule that "you …
Here's a scenario that can happen in a patent case: The patentee serves an opening expert report alleging infringement. Your expert responds, detailing every reason why the design documents show non-infringment. The patentee then serves a reply expert report, citing new documents that it says show infringement.
What do you do now? There are at least four answers: (1) move for leave to serve a sur-reply report to address the new docs; (2) just serve a sur-reply report, without leave, and fight the inevitable motion to strike; (3) skip the report but have the expert be prepared to discuss the new papers at deposition, and hope plaintiff asks; or (4) just plan to address the new …
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