Inequitable Conduct Can Render all Patents in a Patent Family Unenforceable through Infectious Unenforceability

In Guardant Health, Inc. v. Foundation Medicine, Inc., 1-17-cv-01616 (DDE 2020-01-07, Order), the Court rejected the Plaintiff’s argument that an inequitable conduct claim must be related only to the prosecution of the patent-at-issue in ruling on plaintiff’s motion to dismiss defendants’ infectious unenforceability counterclaims.  In the case, the Defendants’ theory as to the unenforceability of U.S. Patent No. 9,902,992 (the ’992 patent) was not based on inequitable conduct said to have occurred during the ’992 patent’s prosecution.  Instead, it rested on the relationship between the ’992 patent and the prosecution of other related patents.

As some background, inequitable conduct regarding any single claim in the prosecution of a patent renders the entire patent unenforceable, not just that specific claim. Moreover, a finding of inequitable conduct can affect not just the improperly-prosecuted patent, but can also render unenforceable any other related patents and applications in the same patent family. This concept is what courts have referred to as the doctrine of “infectious unenforceability.”

Pursuant to this infectious unenforceability doctrine, inequitable conduct associated with one patent may render a related patent unenforceable so long as the inequitable conduct at issue bears “an immediate and necessary relation” to the enforcement of the related patent.  And, an “immediate and necessary relation” requires that “the inequitable conduct that occurred earlier in the chain [of issued patents] ‘must be related to the targeted claims of the ultimately-issued patent or patents sought to be enforced.’”

Turning to the specifics of this case, the Plaintiff made three arguments for dismissal of Defendants’ infectious unenforceability counterclaims.  First, the Plaintiff argued that as to the ’992 patent (unlike the allegedly improper patents), the alleged missing inventor is actually listed as an inventor on the face of the ’992 patent.  Therefore, Plaintiff asserted that there can be no inequitable conduct with respect to the ’992 patent based on misnaming of inventors because it is undisputed that the right inventors are named.  Second, Plaintiff argued that there is not a sufficient relationship between the alleged inequitable conduct at issue and the prosecution of the ’992 patent.  Third, Plaintiff argues that differences between the ’992 patent and the allegedly improper patents preclude a finding of infectious unenforceability.

In considering Plaintiff’s first argument-that Defendants’ counterclaim fails because the alleged missing inventor on the other patents is listed as an inventor on the ’992 patent, the Court found this argument unpersuasive.  This is because, as noted above, Defendants’ theory as to the unenforceability of the ‘992 patent was not based on inequitable conduct in the ’992 patent prosecution itself. Instead, the theory relies on the premise that inequitable conduct with regard to other, previously-filed patent applications are sufficiently related to the enforcement of the ‘992 patent, such that the ‘992 patent is also unenforceable.

In other words, the Court reasoned, merely disclosing, in a subsequent patent application, material that was previously withheld with intent to deceive the USPTO does not save the later issued patent from the consequences of the misconduct.  Instead, to adequately cure any inequitable conduct that occurred during earlier prosecution, the applicant would have to: (1) expressly advise the USPTO of the existence of the misrepresentation; (2) advise the USPTO of what the actual facts are and make clear that further examination in light thereof may be required if any USPTO action has been based on the misrepresentation; and (3) establish patentability on the basis of the factually accurate record.  And, Plaintiff did not assert it took these “curing” steps here.

Next, Plaintiff’s second argument was that Defendants fail to sufficiently plead infectious unenforceability because that doctrine requires a relationship between the alleged inequitable conduct and the prosecution of the ’992 patent.  However, the Court also dismissed this argument because the law on infectious unenforceability requires no direct linkage between the inequitable conduct at issue and the prosecution of the ‘992 patent. The Court first reasoned Plaintiffs position is undercut by the Federal Circuit’s description of the doctrine of infectious unenforceability.  Second, requiring an immediate and necessary relation between the inequitable conduct at issue and the prosecution of the allegedly infected patent would render the doctrine of infectious unenforceability superfluous.

The Court also rejected Plaintiff’s third argument that the doctrine of infectious unenforceability is inapplicable because there are too many differences between the allegedly improper patents and the ’992 patent. Instead, the Court concluded that Defendants had pleaded sufficient facts to demonstrate the required “immediate and necessary relation” between the inequitable conduct at issue and the targeted claims of the ‘992 patent.  The Court found there is a close relationship between the content of the respective patents and the inequitable conduct allegations at issue, particularly given the family history and the priority relationship of the respective patents.  Specifically, there are at least sufficient facts pleaded to plausibly allege that the at-issue patents are part of the same family and that they all share the same priority date.

Thus, in sum, the Court found Defendants had pleaded facts demonstrating an extremely close connection between the content of the ‘992 patent and the other patents and, relatedly, between the nature of the inequitable conduct allegations and the content of the ‘992 patent’s claims.  Thus, Defendants had sufficiently alleged that the ‘992 patent is potentially unenforceable pursuant to the doctrine of infectious unenforceability.

This case is a strong reminder that assertions of inequitable conduct can extend to not just the claims at issue, but to all claims in the patent, and even all patents in the family.  Thus, it goes without saying that extreme care must be taken at all times during the prosecution of all patents.