By Masahito Yokoyama & Scott Daniels
It is a well-established principle of patent law that it is the patentee who bears the burden of proving that the accused product or process falls within the scope of its claims. And yet, the story is not always so simple.
The Federal Circuit’s decision last week in an appeal from the ITC, Wuhan Healthgen Biotechnology Corp. v. U.S. Int’l Trade Comm., is a case in point. The patent claimed a cell culture media supplement or composition. The primary component was albumin which was “less than 2% aggregated albumin.” Relying upon liquid chromatography test results presented by the patentee, the ITC found that the imported composition was at most 1.1% aggregated albumin and therefore determined that it infringed the patent.
On appeal to the Federal Circuit, the accused infringer argued that the patentee had failed to meet its burden of proof. The testing, it asserted, was done too early and failed to account for increased aggregation during storage and shipping to the U.S., which would bring the aggregate amount above the claimed 2% upper limit at the moment of importation, the key point at which the ITC measures infringement.
The Federal Circuit disagreed. It noted (i) the testimony of the patentee’s expert witness that storage and shipping would not result in such a large increase in aggregation, (ii) similar comments in certain peer-reviewed articles, and (iii) the accused infringer’s communications to customers touting the stability of its imported composition. It then explained that even if there were an increase in aggregation, the accused infringer had failed to show that the increase would go above the claimed upper limit. The ITC, the Federal Circuit concluded, was justified in finding infringement.
Takeaway: Interestingly, neither party submitted tests of the accused product’s aggregated albumin level at the moment of importation. And yet the ITC and the Federal Circuit both ruled in favor of the patentee, despite its bearing the burden of proof. The lesson for litigants is that they cannot always rely upon general legal principles and must present as much evidence as possible on the key issues.
