Sometimes an applicant desires to put evidence in the record during patent prosecution. The evidence might be from an expert to establish the teachings of a particular reference, or to establish whether there would be an expectation of success in combining references. Further, evidence can be used to establish secondary factors, such as commercial success.
While such evidence can be very valuable and helpful in some cases, it can also be harmful, especially before the PTAB. While the evidence must be commensurate with the scope of the claims, PTAB judges will often evaluate such evidence in terms of whether it is consistent with the teachings of the specification. And some times, the judges will look at declaration evidence as a means of finding potentially new grounds of rejection. This latter situation is illustrated in the following case from Boehringer Ingelheim (14/694,155).
The Boehringer application relates to a process for making tiotropium bromide which is useful in pharmaceuticals. The claims set forth a particular compound that was rejected by the examiner as being obvious in view of three references, one of which had an inventor (Brandenberg) in common with the application on appeal. Boehringer used a strategy that can be very helpful - where the author of the cited reference confirms the in-applicability of that reference. See the previous post here discussing exactly that approach). But as noted in that post, be wary as there can be pitfalls with declarations.
Here, Boehringer was so focused on the great advantages of the new invention, they took there eyes off the ball and created other problems where none previously existed. Specifically, the PTAB characterized the Brandenberg declaration as including an assertion that only a particular zeolite (zeolite 4A) is suitable for the claimed process, and that it was "crucial" to use acetone in the process. From there, the PTAB noted that the claim on appeal was not limited to that particular zeolite or to the use of acetone, and thus raised questions as to whether the claims were inoperable, and thus not enabled across the full scope of the claim. Specifically, the PTAB explained that:
So, be careful in your declarations that the inventor's exuberance for his invention does not get carried too far and create a problem that was not there before.