Defending Your Patent from Inter Partes Review

Feldstein Ph.D., Mark J.

Arguments . . .
The construction of claims can be critical to the outcome of an IPR. Indeed, a narrower construction is almost always preferred to distinguish over prior art. While the board will apply the "broadest reasonable interpretation," that construction must be consistent with the specification.

It can be important for the patentee to direct the board to the context of the specification to undermine an overbroad interpretation advocated by the challenger. Care must be given, however, to not limit the claims by argument in a way that creates new noninfringement positions for the challenger. Indeed, forcing the patentee to take a narrow claim construction position may be the challenger's principle motivation.

There are also many ways to attack the asserted references and reference combinations. Among these are several avenues to wholly disqualify an alleged prior art reference. New evidence, not available during the original prosecution, can also be used to defeat rejections and actually strengthen the patent.

For example, at least for patents examined under the pre-America Invents Act rules,6 it may be possible to "swear behind" the reference based on the patentee's prior invention. This entails submitting evidence that the invention was conceived prior to the publication date of the reference (or, in the case of a patent document, its filing date). It may also be possible to overcome an allegedly anticipatory reference by proving that it is not enabled or that a claim element is not inherent in its disclosure.

Obviousness defenses include all of the arguments commonly employed during normal patent prosecution to show that the claims are patentable in light of the prior art. These include the lack of motivation to combine references, lack of reasonable expectation of success, teaching away from the claimed invention, and the failure of others. New nonobviousness arguments also may have become available through continued research or because the claimed invention has since been embodied in a commercial product. These can include evidence of commercial success, recognition and praise by experts in the field, and unexpected properties or benefits of the claimed invention.

The board accepts evidence supporting all of the above contentions in the form of affidavits and expert declarations. Thus, inventors and coworkers may need to be located and asked to sign affidavits attaching relevant notebook pages and experimental data "swearing behind" the date of a reference. Likewise, experts must be retained to consider, then present, declaration evidence explaining the prior art or other evidence of the patentability of the invention.

Each of these endeavors represents an investment in time and money, and it will typically be necessary to focus on only the most promising arguments, given budgetary constraints, page limits, and the short response time allotted to the patentee.