Imagine That IP Law Blog

The recent September 2023 Federal Circuit decision in Elekta Ltd. v. Zap Surgical Systems, Inc., Case No. 21-1985 (Fed. Cir. 2023) shows that patent applicants should give consideration to formally addressing – on the record during prosecution - the relevance of the prior art references disclosed in their information disclosure statements (“IDSs”) to avoid later misinterpretation by tribunals in potential future Inter Partes Review (IPR) proceedings and court decisions.  Such misinterpretation may lead a tribunal to combine IDS references from irrelevant fields and invalidate patents based on obviousness.  This is what happened in Elekta, where the absence of assertions identifying which references listed in the applicant’s IDS were not relevant to the claimed invention, led to any of the references listed in the IDS as being relevant, such that “a skilled artisan would have been motivated to combine the references” to achieve the applicant’s invention.  Id. at 10.  In this case, the CAFC decided that there would have been a “motivation to combine” any of those references for purposes of supporting obviousness rejections under 35 U.S. Code § 103.

In Elekta, the claimed invention US 7,295,648 B2 - Method and apparatus for treatment by ionizing radiation arrived at the Federal Circuit on Elekta’s appeal after the PTAB found the ’648 patent obvious and unpatentable.  While the invention centers on a radiation therapy/surgery device for treating a patient with radiation therapy, during prosecution, Elekta included references in its IDS disclosing prior art in the field of radiation imagery.  Notably, the Court emphasized that during the prosecution of the ’648 patent, patents directed to radiation imagery were disclosed in Elekta’s IDS, but these patents “were not distinguished [by Elekta] based on an argument that imaging devices were not relevant art.” Id. at 9. (emphasis added).

Accordingly, Elekta’s failure during prosecution to assert that the radiation imagery patents cited in the IDSs were not relevant opened the door for the Court to determine the relevance of the patents cited in Elekta’s IDS, on its own.

In making its own relevance analysis, the Federal Circuit followed the PTAB’s view as to the relevance of the prior art references in Elekta’s IDS.  The lower PTAB tribunal determined that both radiation therapy references and radiation imagery references were relevant to Elekta’s invention.  Based on this broad scope of relevance, the PTAB then “framed the pertinent field as one that ‘includes the engineering design of sturdy mechanical apparatus[es] capable of rotationally manipulating heavy devices in three dimensions oriented in a variety of approach angles with high geometrical accuracy, in the context of the radiation imaging and radiation therapy environment.’”  Id.  (emphasis added).  Much to Elekta’s dismay, the PTAB’s broad scope of relevance paved the way toward its finding that there was a motivation to combine radiation therapy references and radiation imagery references to support a § 103 rejection of the ’648 patent.

Essentially, if an Applicant does not define or at least address the scope of relevance of the references cited in its IDS, a Court or PTAB may do so instead.  As a consequence, the applicant’s IDS becomes a smorgasbord of prior art references – some more or less analogous to the applicant’s specific field of invention – that may be reviewed to select a combination that supports an obviousness rejection based upon an alleged motivation to combine any of the references, no matter how similar.  

Bearing in mind the type of references that may typically be included in an IDS, such as those ranging from general background information on the field of the applicant’s invention to more specific references that may be directly on point to a particular claimed feature, what is determined as relevant art in an IDS based upon the Elekta case appears to pose an interesting twist to the traditional scheme of information disclosure as defined by the Manual of Patent Examining Procedure (“MPEP”).  As patent practitioners can attest, MPEP 2001 regarding Duty of Disclosure, Candor, and Good Faith requires that “[e]ach individual associated with the filing and prosecution of a patent application has a duty of candor and good faith in dealing with the Office, which includes a duty to disclose to the Office all information known to that individual to be material to patentability.” MPEP 2001 e9, r07. 2022. (emphasis added).

So first and foremost, an IDS must disclose what is known to be “material to patentability” (as further defined in MPEP 2001.05) to satisfy the duty of disclosure.  Then, according to Elekta, patent applicants and practitioners should account for the degree of relevance of the prior art references in the IDS: would there be a motivation to combine any of the references to arrive at the claimed invention, for purposes of a possible obviousness rejection under § 103? “Obviousness requires, inter alia, a finding that a skilled artisan would have been motivated to combine the teachings of prior art in such a way that the combination discloses the claimed limitations.” Id. at 8. (emphasis added).

For Patent Applicants and Patent Prosecutors

While the pendulum may be swinging against the practice of saying as little as possible in prosecution, in most cases, Patent Prosecutors will want to continue to avoid making robust statements regarding the degree of relevance of prior art references, as there are many ways that these statements may come back to hurt the patent.  A potential approach to consider during prosecution for addressing the relevance of the prior art references disclosed in an IDS may be to include a generic statement in a communication or transmittal letter accompanying the IDS submitted to the USPTO.  Such a generic statement may assert that the applicant is providing the IDS pursuant to information disclosure requirements but does not concede to any admissions or inferences of the relevance of the cited references relative to whether any combination of the references would support a “motivation to combine” for a determination of § 103 obviousness.

For Petitioners in IPR Proceedings

Elekta suggests that, in the absence the Patentee’s statements on the record to the contrary during prosecution, there may a potential pathway to invalidating patents at the PTAB, based on a combination of the art cited during prosecution – either by the patent owner in IDSs or by the Examiner in office actions.  After Elekta, the Petitioner holds the high ground, as the onus of providing formal statements to preempt inferences of relevance falls on the patent owner.   

For Patent Owners in IPR Proceedings

A potential strategy for patent owners to consider when responding to a petition for IPR at the PTAB alleging the obviousness of the patent owner’s patent involves determining whether the prior art references cited by the petitioner are actually analogous to the patent owner’s invention. In addition to addressing and preempting any inferences of the relevance of the references cited during prosecution of its patent at the examining branch of the USPTO, a patentee may also challenge the prior art cited in IPR