What’s a “but for”? USPTO proposes changes to duty of disclosure

Those who have filed patent applications in the US will no doubt be familiar with the onerous duty of disclosure requirements. The USPTO is currently proposing rule changes which could simplify the task of determining what should and should not be disclosed, and reduce paranoia surrounding the duty.


The Importance of Duty to Disclose

Under US patent law, applicants and other individuals associated with the filing and prosecution of a patent application, have a duty to disclose to the USPTO all information known to that individual to be “material to patentability”. There has historically been a great deal of paranoia surrounding this requirement; and with good cause. Failing to satisfy the duty of disclosure requirements can (and on many occasions does) invalidate a patent.

The paranoia has been fed by a strong preference on the part of US litigators to explore duty of disclosure in an attack on patent validity. This is entirely understandable: this avenue provides an opportunity to have a patent quashed in its entirety without having to explore complex technical issues such as obviousness.

As a result of the paranoia, there has been a tendency to act on the side of caution, and disclose anything and everything that comes to light. Often, due to the times at which material is found, this cases significant hurdles in the patent process, sometimes requiring surrendering a granted patent just so that a document of questionable relevance can be officially marked as “disclosed”.

The Proposed Changes

In general terms, the USPTO is proposing a “but-for-plus” standard in relation to determining materiality. This follows a US Federal Circuit decision in Therasense Inc v Becton Dickinson and Co (Federal Circuit 2011). In that decision, the court held that “[w]hen an applicant fails to disclose prior art to the PTO, that prior art is but-for material if the PTO would not have allowed a claim had it been aware of the undisclosed prior art”. In this manner, it was held that the Court must determine, for an undisclosed piece of prior art, whether the USPTO would have allowed a particular claim of a patent if that piece of prior art had been disclosed.

With Therasense in mind, the USPTO has proposed the following rule:

Information is material to patentability under Therasense if:

(1)   The Office would not allow a claim if it were aware of the information, applying the preponderance of the evidence standard and giving the claim its broadest reasonable construction; or

(2)   The applicant engages in affirmative egregious misconduct before the Office as to the information.

As a result, it would seem that the mere failure to disclose information would not be considered material to patentability if the claim in question is allowable even in light of that information. That is, it would be difficult to invalidate a patent for failure to disclose prior art that is, at a practical level, of limited relevance to the patentability of the claims.

This, on face value, presents a fairly pragmatic approach. The benefits are twofold: applicants are provided improved guidance as to what need and need not be disclosed; and the USPTO should in theory receive a reduced quantum of material from applicants (hence improving their ability to fully consider what is indeed provided). However, it is impossible to predict the actual effects, should the rule change be effected.

As noted, these are proposed changes only. In the meantime, applicants should remain diligent in informing their attorneys of everything and anything of potential relevance to their patent application.