Boston Scientific v. Cordis (Fed. Cir. 2009)

Elements disclosed in different embodiments of a single prior art reference can be combined to fi nd claims obvious, according to the Federal Circuit.

In 2003, Boston Scientifi c sued Cordis for infringing U.S. Patent 6,120,536 (the ’536 patent), which relates to a drug-eluting expandable stent with a coating that has a non-thrombogenic surface. The stent has a metal core surrounded by a drugged layer that is surrounded by the non-thrombogenic layer. At trial, the jury found that the asserted claims were infringed and would not have been obvious based on, among other references, U.S. Patent 5,545,208 (the ’208 patent) and U.S. Patent 5,512,055 (the ’055 patent). The District Court upheld the jury’s fi ndings and denied Cordis’s motion for judgment as a matter of law.

With regard to the fi nding of non-obviousness, the district court reasoned that the ’055 patent, which discloses esophageal stents, does not suggest the use of metal in a stent, and that there was no evidence of motivation to combine the ’055 patent with other references. In addition, the District Court reasoned that the ’208 patent does not teach a metallic stent having a two-layer coating, and the failure of the assignee of the ’208 patent to create the claimed stent after more than a decade of work evidenced a lack of motivation to combine the features of its various prior art stents with each other.

On appeal, Cordis argued that the District Court erred in denying Cordis’s motion for JMOL of invalidity of the ’536 patent on the ground of obviousness. According to Cordis, the ’208 patent alone rendered the asserted claims obvious. The ’208 patent discloses two embodiments in Figures 3B and 4. Figure 3B discloses a polymer stent made of a drugeluting polymer with a barrier topcoat. The stent and the topcoat are referred to in the patent as separate “layers.” Figure 4 discloses a metallic stent with a drug-eluting polymer coating. The drug-eluting polymer coating in Figure 4 is referred to with the same numeral as the drug-eluting polymer stent of Figure 3B.

Applying KSR Int’l v. Teleflex, the Federal Circuit found that it would have been obvious to combine the embodiment in Figure 3B with the embodiment in Figure 4 to arrive at a metal stent with two coating layers. The Federal Circuit stated that combining the two elements disclosed adjacent to each other in a prior art patent does not require a leap of inventiveness. Accordingly, the Federal Circuit reasoned that 35 U.S.C. § 103 bars patentability because the combination of the two embodiments was simply a predictable variation. The Federal Circuit stated that the weak secondary considerations of nonobviousness do not overcome the strong prima facie showing that the ’208 patent renders the asserted claims obvious.

Practice Tip:

When evaluating patentability of an invention, it may be benefi cial to pay close attention to the elements of various embodiments disclosed in a prior art reference that can be combined to render a predictable variation.