Lack of Diligence in Deposing Key Inventor Precludes Amending Answer to Add Inequitable Conduct Defense

January 17, 2024

Reading Time : 2 min

The Central District of California denied a defendant’s motion for leave to amend to allege inequitable conduct due to the defendant’s delay in deposing a key inventor until the end of fact discovery. The district court held that the defendant neither exercised diligence nor established good cause based on the inventor’s deposition to warrant amending its answer.

In a patent infringement lawsuit over printer and printing method patents, Defendant deposed the first named inventor of the patents two weeks before the end of fact discovery. The inventor testified that he had used information about a printhead manufactured by a third party in the design of the claimed inventions. Patentee then produced related documents after the deposition and two days before the close of fact discovery. Defendant argued that Patentee intentionally withheld this critical information about the printhead until the end of discovery, depriving Defendant of the ability to allege inequitable conduct sooner. Defendant filed a motion to amend its answer to assert inequitable conduct following the Patentee’s production—eight months after the deadline to amend pleadings.

Patentee argued in opposition to the motion that it had produced relevant documents about the claimed invention’s functionality earlier in the case, that the information that formed the basis for Defendant’s motion was cumulative of prior discovery and that the information was not material to patentability. Patentee further argued that Defendant was at fault for delaying the deposition at which it learned of the printhead information until two weeks before the end of fact discovery and four months before trial. Thus, Defendant was not diligent.

The court agreed with Patentee, concluding that Defendant was not diligent and thus failed to show good cause to modify the court’s scheduling order pursuant to Rule 16(b)(4) long after the deadline to amend pleadings. Although Defendant noticed the deposition in March and the parties had a dispute over its location, the district court faulted Defendant for waiting several months to bring the location dispute to its attention. The court also found that Defendant failed to identify any testimony that supported a “sudden revelation of inequitable conduct.” The court also held that Defendant failed to meet the requirements to amend its pleading under Rule 15 because, inter alia, it failed to alleged facts sufficient to support a reasonable inference of specific intent.

Practice Tip: When choosing the timing of key depositions, parties must consider the potential consequences of discovering relevant information late in the discovery period. Courts may be reluctant to permit amendments or additional discovery when it is likely to be time-consuming, costly or delay resolution of the case even if that discovery was requested, but not provided earlier in the case if the requesting party did not seek the court’s assistance in ensuring that such discovery was provided earlier.

MGI Digital Technology SA v. Duplo USA Corporation, 8-22-cv-00979 (CDCA Oct. 17, 2023).

Share This Insight

Previous Entries

IP Newsflash

April 7, 2025

The Central District of California denied a defendant’s motion to dismiss or transfer plaintiff’s first-filed declaratory judgment action based on defendant’s later-filed patent infringement suit in Wisconsin.  Though suit was seemingly imminent when defendant advised plaintiff it might be infringing defendant’s patents, plaintiff responded by requesting a licensing agreement in lieu of litigation. The court found that plaintiff’s action was not anticipatory forum-shopping litigation because plaintiff only filed suit after defendant neglected to respond to its licensing offer.

...

Read More

IP Newsflash

April 1, 2025

The District of Delaware recently denied in part a motion to compel production of documents and testimony between a patentee and potential investors, valuation firms and an international bank based on the common interest exception. In so doing, the court reaffirmed that disclosure of privileged information to third parties will generally waive privilege unless it can be shown that the parties’ interests are identical and the communications are legal, not solely commercial.

...

Read More

IP Newsflash

March 24, 2025

The Federal Circuit affirmed a Patent Trial and Appeal Board (PTAB) final written decision holding that the prior art exception of AIA Section 102(b)(2)(B) does not apply to a prior sale by an inventor when the sale is conducted in private. According to the Federal Circuit, a sale must disclose the relevant aspects of the invention to the public to qualify for the prior art exception of Section 102(b)(2)(B).

...

Read More

IP Newsflash

March 21, 2025

Under the Lanham Act, a plaintiff who prevails on a trademark infringement claim may be entitled to recover the “defendant’s profits” as damages. The Supreme Court in Dewberry Group, Inc. v. Dewberry Engineers Inc. unanimously construed “defendant’s profits” in 35 USC § 1117(a) to mean that only the named defendant’s profits can be awarded, not the profits of other related corporate entities. The Court, however, left open the possibility that other language in § 1117(a) may allow for damages linked to the profits of related entities, if properly raised and supported.

...

Read More

IP Newsflash

March 13, 2025

In a series of rulings on a motion in limine, the District of Delaware recently distinguished between what qualifies as being incorporated by reference and what does not for the purposes of an anticipation defense. In short, a parenthetical citation was held to be insufficient, while three passages discussing a cited reference met the test.

...

Read More

IP Newsflash

March 4, 2025

On February 28, 2025, the USPTO announced that it was rescinding former Director Vidal’s 2022 memorandum on discretionary denials by the Patent Trial and Appeal Board. The 2022 memorandum effectively narrowed the application of discretionary denials in cases with parallel district court litigation by specifying instances where discretionary denial could not be issued. With the withdrawal of the memorandum, individual PTAB panels will regain flexibility in weighing discretionary denials. While the long-term effect of that increased flexibility is not yet known, the immediate effect is likely to be a shift towards the discretionary analysis applied by PTAB panels before the issuance of the memorandum.

...

Read More

IP Newsflash

March 3, 2025

A District of Delaware judge recently granted a defendant’s motion to include a patent prosecution bar in its proposed protective order after determining that litigation counsel’s ability to practice before the Patent Office—without ever having represented the plaintiffs at the Patent Office in the past—weighed heavily in favor of the bar.

...

Read More

IP Newsflash

February 12, 2025

The Federal Circuit recently reversed a district court decision that found a patent that did not describe after-arising technology failed to satisfy the written description requirement. In so doing, the Federal Circuit explained that written description and enablement are evaluated based on the subject matter that is claimed, not the products that practice those claims. As a result, the patentee was not required to describe unclaimed, later-discovered features of the accused products despite the broad language in the claims that undisputedly covered the products.

...

Read More

© 2025 Akin Gump Strauss Hauer & Feld LLP. All rights reserved. Attorney advertising. This document is distributed for informational use only; it does not constitute legal advice and should not be used as such. Prior results do not guarantee a similar outcome. Akin is the practicing name of Akin Gump LLP, a New York limited liability partnership authorized and regulated by the Solicitors Regulation Authority under number 267321. A list of the partners is available for inspection at Eighth Floor, Ten Bishops Square, London E1 6EG. For more information about Akin Gump LLP, Akin Gump Strauss Hauer & Feld LLP and other associated entities under which the Akin Gump network operates worldwide, please see our Legal Notices page.