Jang v. Boston Scientific Corp., No. 16-1275 (Fed. Cir. 2017)Annotate this Case
Dr. David Jang, M.D., is the named inventor of the patent, which is directed to a coronary stent. Jang assigned the patent to BSC. BSC agreed to pay a royalty if it ever produced a product that would infringe the patent. Jang sued, based on BSC’s “Express stent.” BSC sought ex parte reexamination, then sought to include invalidity defenses in Jang’s suit. The district court denied the motion, deeming invalidity defenses “irrelevant” as to whether BSC owed royalties for past sales. The Patent and Trademark Office subsequently cancelled the asserted claims as unpatentable. The court denied BSC’s motion in limine to preclude Jang from presenting a doctrine of equivalents theory, finding that Jang’s experts sufficiently explained his doctrine of equivalents theory in their expert reports. The jury ultimately found no literal infringement, but found infringement under the doctrine of equivalents. Following through on its earlier decision, the district court conducted an evidentiary hearing on ensnarement. Concluding that Jang did not meet his burden of persuasion, which includes providing a proper hypothetical claim that does not ensnare the prior art, the district court vacated the jury verdict and entered judgment of non-infringement. The Federal Circuit affirmed the entry of judgment of non-infringement.