Executive Summary
On November 13, 2025, the U.S. District Court for the District of Massachusetts (court) found that patent applicant, Inline Plastics Corp. (Inline), engaged in inequitable conduct when it failed to disclose two inventors from an external consulting firm, 4Sight, Inc. (4Sight) during the patent application process. The court found that the omission of the two inventors was material and done with the specific intent to deceive the U.S. Patent and Trademark Office (USPTO). The court thus concluded that the intentional exclusion of inventors constituted inequitable conduct, and ruled that the asserted patents and the entire patent family were unenforceable. This case serves as a reminder that individuals involved in the prosecution of a patent application have a duty of candor and good faith in dealing with the USPTO. Importantly, inequitable conduct in the prosecution of one patent application can result in invalidity of an entire patent family.
Background
Individuals such as inventors, applicants, and attorneys, have duties of candor, good faith, and disclosure to the USPTO under Rule 56.1 A breach of any of these responsibilities may constitute inequitable conduct. Importantly, inequitable conduct for a single claim renders an entire patent, and potentially the entire patent family, unenforceable, regardless of whether the patent is otherwise valid.
To successfully utilize the defense of inequitable conduct, a party must show that the accused party:
(2) did so with specific intent to deceive the USPTO.
Regarding element (1), withheld information is deemed “material” if there is a “substantial likelihood that a reasonable patent examiner would have considered the information important in deciding whether to approve a patent.” An exception to this but-for materiality requirement is affirmatively egregious misconduct, which typically involves deliberately making a false statement to the USPTO.2 However, mere nondisclosure of material information does not constitute affirmative egregious misconduct.
Regarding element (2), specific intent to deceive the USPTO, requires clear and convincing evidence that the accused party: (1) knew of the information; (2) knew it was material; and (3) made a deliberate decision to withhold the information from the USPTO.3 Intent to deceive the USPTO must be the single most reasonable inference from the evidence, and if multiple reasonable inferences can be drawn, intent to deceive is not found. A person’s purposeful omission or misrepresentation is relevant to such an inference.4
Case Summary
In Inline Plastics Corp. v. Lacerta Group, Inc., Inline asserted five patents against Lacerta Group, Inc. (Lacerta), asserting that Lacerta infringed their patented technology. All five patents claimed priority to the same provisional patent application. In response, Lacerta argued that the asserted patents were unenforceable under inequitable conduct because: (1) Inline failed to name joint inventors who contributed to the conception of the claims, and (2) Inline materially misrepresented teachings of a prior art reference. Following its analysis, the court found that Inline engaged in inequitable conduct by omitting the inventors. Furthermore, the unenforceability of the asserted patents would extend beyond those asserted and to all related patents in the same patent family. On point (2), the court found in favor of Inline, finding that Inline did not engage in inequitable conduct regarding the teachings of the prior art reference. The analysis of point (1) is discussed below.
Element 1—Materiality
In regard to element (1) of the inequitable conduct test, the court concluded that inventorship is material because it is a critical requirement for obtaining a patent. To be a joint inventor, the person must contribute in some significant manner to the conception or reduction to practice of the invention, contribute to the claimed invention in a manner that is not insignificant, and do more than merely explain well known concepts and state of the art.5
The two inventors of 4Sight prepared design drawings for Inline in October 2022, and elements from the design drawings were disclosed in the asserted patents. According to the court, the elements in the design drawings contributed to the conception of at least one claim of each of the patents asserted. Further, none of the named inventors from Inline listed on the asserted patents began working on the invention until November 2022 or later, which post-dates the design drawings from 4Sight. Therefore, the court concluded that 4Sight had conceived key aspects of the claimed inventions. In this regard, the court determined that the omission of the two inventors from 4Sight as joint inventors was material.
Element 2—Specific Intent
Regarding element (2) of the inequitable conduct test, the court concluded by clear and convincing evidence that Inline acted with specific intent to deceive the USPTO when omitting the two inventors from 4Sight as joint inventors on the asserted patents. Here, the court found that the specific intent to deceive the USPTO is the single most reasonable inference that could be drawn from the circumstances.
The two inventors from 4Sight conceived of an inventive feature (tear strip feature) of the asserted patents that was present in the patent drawings. Additionally, the court found that there was temporal inconsistency regarding when Inline maintained their invention date and when the named Inline inventors had started working on the invention. In this regard, the named Inline inventors offered vague and contradictory testimony regarding their contributions to the claimed inventions. Further, the court found testimony from Mr. Orkisz, a representative for Inline, to be “evasive, contradictory, and not credible.”
Taken together, the court found the evidence to indicate a deliberate effort to cut 4Sight out of the patent process after obtaining the design concepts from 4Sight. As such, the court determined that there is no reasonable alternative inference that explains this pattern of conduct except for a specific intent to deceive the USPTO. The court thus concluded that Inline committed inequitable conduct, rendering the five asserted patents, and the entire patent family unenforceable.
Implications and Conclusion
When inventorship is intentionally misrepresented, the courts may apply the harsh but established equitable remedy of unenforceability across an entire patent family. This ruling makes clear the importance of candor and good faith during the patent application process. Applicants should have a thorough discussion of inventorship contributions, and any concerns regarding inventorship should be promptly addressed.
While this case may be subject to further legal proceedings, it serves as an important reminder of the potential consequences of intentional deception, or actions that support a reasonable inference of deception at the USPTO.
For questions regarding patent strategies, please contact any member of Wilson Sonsini’s Patents and Innovations practice.
[2] See In re Method of Processing Ethanol Byproducts & Related Subsystems (‘858) Pat. Litig., No. 110CV00180LJMDML, 2016 WL 4919980.
[3] Belcher Pharms., LLC v. Hospira, Inc., 11 F.4th 1345, 1353 (Fed. Cir. 2021).
[4] Luv n’ Care Ltd. v. Laurain, 98 F.4th1081, 1099 (Fed. Cir. 2024).
[5] Pannu v. Iolab Corp., 155 F.3d 1344, 1351 (Fed. Cir. 1998).
