On Tuesday, the Federal Circuit partially reversed a decision by the Patent Trial and Appeal Board that invalidated a number of claims in a Smith & Nephew, Inc. patent during inter partes reexamination. While many of Smith & Nephew’s arguments on appeal were unsuccessful, the Federal Circuit agreed with the patent holder that the board incorrectly relied on non-analogous prior art to find several of the challenged claims invalid.
The patent claims at issue are directed to a surgical tool for cutting through semi-rigid tissue. Certain claims in the patent were found invalid by the board based on a primary prior art reference in view of two secondary prior art references. On appeal, Smith & Nephew argued that the primary prior art reference, which relates to winding a glass fiber strand to form packages, was not reasonably pertinent to the surgical field and, thus, would not have been considered by an inventor trying to solve the problem of cutting through large amounts of semi-rigid tissue. The Federal Circuit sided with Smith & Nephew, found that the primary prior art reference was non-analogous, and held that the board erred by too narrowly construing the problem addressed in the patent. However, because a number of the claims invalidated by the PTAB based on this non-analogous prior art reference were also found to be invalid on other grounds, only three claims in the patent were resurrected by the Federal Circuit’s ruling.
While Smith & Nephew’s appeal was successful only with respect to a few of the claims in its patent, the Federal Circuit’s decision serves as a reminder to carefully examine all of the factual prerequisites of obviousness when crafting a rebuttal argument to an obviousness rejection or challenge. Most rebuttal arguments tend to focus only on the differences between the claimed invention and the prior art and ignore the other factual prerequisites, such as the scope and content of the prior art. Here, the conventional arguments as to the differences between the claimed invention and the prior art were unsuccessful before the board and again on appeal. But, Smith & Nephew’s focus on the less conventional and under-utilized argument relating to the scope and content of the prior art and, more specifically, whether the prior art is analogous, saved a handful of claims from invalidity.
In short, whether you are arguing against an obviousness rejection by an examiner during prosecution, an invalidity challenge before the board during a post-grant proceeding, or an invalidity attack in a district court case, do not forget to first assess whether the prior art is even analogous. If the prior art is from a different field of endeavor, your argument should include compelling reasons as to why it would not have been reasonable for a person of ordinary skill in the art to consider the prior art in order to solve the problem confronting the inventor.
If you are interested in reading the entire opinion from the Federal Circuit, it can be found here (17-1008).