April 26, 2018

The Old “Practicing the Prior Art” Defense

By Bryan K. Wheelock, Principal

In 01 Communique Laboratory, Inc. v. Citrix Systems, Inc., [2017-1869] (April 26, 2018), the Federal Circuit affirmed the district court’s Order denying 01 Communique a new trial on the issue of infringement.

The case involved U.S. Patent No. 6,928,479 on a System Computer Product and Method for Providing a Private Communication Portal. The jury returned a split verdict. It concluded that Citrix had not established that claims 24 and 45 were invalid, but that 01 Communique had not established that Citrix’s GoToMyPC product infringed those claims. 01 Communique’s moved for a new trial because Citrix resorted to “a well-known defendant’s trick” — known as the “practicing the prior art defense” — which “was improper, misleading, and devastatingly prejudicial to the integrity of the trial.”

The Federal Circuit found that Citrix’s infringement defense was firmly rooted in a limitation-by-limitation comparison between the asserted claims and the GoToMyPC product. The Federal Circuit found that Citrix did argue that under the trial court’s claim construction claims 24 and 45 were valid, but not infringed, but that if Communique attempted to expand the scope of its claims to include Citrix’s systems, then the claims would be invalid in light of the prior art.

The Federal Circuit has previously stated that “there is no ‘practicing the prior art’ defense to literal infringement. The problem with such a defense is that it can potentially allow a defendant to skirt evidentiary hurdles and conflate the infringement and invalidity inquiries. While the issue of whether asserted claims read on the prior art is relevant to the question of invalidity, “accused infringers are not free to flout the requirement of proving invalidity by clear and convincing evidence by asserting a practicing prior art defense to literal infringement under the less stringent preponderance of the evidence standard.

While it is clear that an accused infringer cannot defeat a claim of literal infringement or establish invalidity merely by pointing to similarities between an accused product and the prior art, this does not preclude a litigant from arguing that if a claim term must be broadly interpreted to read on an accused device, then this same broad construction will read on the prior art. The Federal Circuit found that Citrix did not rest on an improper “practicing the prior art” defense, but instead correctly recognized that claim terms must be construed the same way for both invalidity and infringement.

The Federal Circuit rejected the argument that comparisons between the accused device and the prior art is improper, and noted that any prejudice would be cured by the district court’s jury instructions.

The Federal Circuit affirmed the denial of a new trial.