Boston Scientific Stent Patent Obvious in Light of KSR

The new obviousness standard set forth in KSR v. Teleflex, 550 U.S. 398 (U.S. 2007), has put to rest yet another patent into the invalidity graveyard. After a district court found a Boston Scientific stent patent valid and infringed, the Federal Circuit applied the KSR standard and reversed the district court ruling, finding the patent invalid.

The reason for this is simple: after Boston Scientific won the jury trial, a new standard was put in place as to what renders a patent obvious. Before KSR, a patent was non-obvious if one reference contained some of the elements of a patent claim, and a second reference contained the remaining elements, but there was no explicit statement suggesting that the two references should be combined to result in the resulting patent claim. In other words, there must have been some motivation to combine the two references in order to render a patent claim obvious. Typically, rendering a patent obvious requires two references. After KSR, there is no longer a requirement of an explicit motivation to combine references. Now, two references may be combined if common sense would lead one skilled in the field of science in question to combine the references. The Federal Circuit has taken this rule one step further, and has found that a patent can be rendered invalid for obviousness with only one reference.

In Boston Scientific v. Cordis Corp. (Fed. Cir. 2009), the Federal Circuit applied the KSR standard to Boston Scientific’s patent, U.S. Patent 6,120,536 (“the ’536 patent”), using only one reference, namely U.S. Pat. No. 5,545,208 (“Wolff”). Wolff described every element of the ’536 patent, but they were described in separate embodiments within the patent. Figure 3B (along with its corresponding description in the specification in Wolff), described some of the elements, and Figure 4 (along with its corresponding description in the specification) described the remaining elements. It is common practice to insert a catch-all statement at the end of a specification stating that “each embodiment, or any combination of the embodiments, are contemplated in the invention.” This allows the patentee to later change the patent claims to include a mixture of the embodiments because there is an explicit reference that a combination of the embodiments were contemplated by the inventor.

Wolff, however, had no such catch-all statement. Thus, the district court rejected Cordis’ argument that the two embodiments described in Wolff render the ’536 patent obvious because there was no explicit motivation to combine them. Unfortunately for Boston Scientific, KSR was issued after the district court’s ruling, loosening the strict requirements for rendering a patent obvious.

The Federal Circuit explained that “all the limitations of claim 8 were found in two separate embodiments in Wolff pictured side by side… Combining two embodiments disclosed adjacent to each other in a prior art patent does not require a leap of inventiveness.” In so stating, the Federal Circuit has opened the door to holding patents invalid for obviousness using only one reference.

What about Anticipation?

It is unclear as to how this ruling with affect how a reference anticipates a patent. A reference anticipates a patent, and thus renders it invalid, when all of the elements of a patent are found in one reference. But even though all the elements of the patent claim were found in Wolff, the Federal Circuit found the patent obvious, not anticipated. Case law regarding this issue should be closely watched in order to further clarify the difference between anticipation and obviousness with regards to one prior art reference.