By Donald Zuhn --
On Monday, the Federal Circuit affirmed a finding on summary judgment by the District Court for the Northern District of California that the asserted claims of U.S. Patent Nos. 4,767,708 and 5,126,270 and certain asserted claims of U.S. Patent No. 6,017,745 are invalid, and that the remainder of the asserted claims of the '745 patent are not infringed by Defendants-Appellees Hoffmann-La Roche, Inc., Roche Molecular Systems, Inc., Roche Diagnostic Systems, Inc., Roche Biomedical Laboratories, Inc., The Perkin Elmer Corporation, Laboratory Corporation of America Holdings, Roche Diagnostic Corp., Laboratory Corporation of America, and Applera Corp. (Roche). In affirming the District Court's determination of invalidity and noninfringement, the Federal Circuit concluded that the lower court did err in holding the claims invalid for failure to meet the written description requirement or in performing its infringement analysis.
The patents in suit are related to, inter alia, recombinant plasmids for the enhanced expression of DNA polymerase I (which is encoded by the polA gene), bacterial strains containing such plasmids, and methods for conditionally controlling the expression of DNA polymerase I using such bacterial strains. The claimed plasmids, bacterial strains, and methods seek to overcome a problem that existed in the prior art -- namely that bacterial host cells transformed with a plasmid containing the entire polA gene overexpress DNA polymerase I, which is lethal in bacterial host cell. In the claimed plasmids, bacterial strains, and methods, this problem is overcome by removing most or all of the polA promoter such that the cloned polA gene "contains essentially none of or at the most only a portion of the activity of its natural promoter."
In August of 1994, Plaintiffs-Appellants Carnegie Mellon University and Three Rivers Biologicals, Inc. (Carnegie Mellon) brought suit against Roche for patent infringement, asserting that Roche's recombinant plasmid pLSG5, which can be used to express Thermus aquaticus (Taq) DNA polymerase, infringes the '708 and '270 patents. In response, Roche filed separate motions for summary judgment of invalidity for lack of written description and noninfringement. The District Court granted Roche's motion for summary judgment of noninfringement of the '708 patent and Roche's motions for summary judgment of invalidity of the '708 and '270 patents. With respect to Roche's motion for summary judgment of invalidity of the '708 patent, the District Court concluded that the '708 patent lacked an adequate written description under Regents of University of California v. Eli Lilly & Co., 119 F.3d 1559 (Fed. Cir. 1997), since the claims encompass a cloned polA gene from any bacterial source, but the specification only describes plasmids containing the polA gene from Escherichia coli.
In January of 2001, Carnegie Mellon filed a second patent infringement suit against Roche, this time alleging infringement of the '745 patent. Roche again moved for summary judgment of invalidity for lack of written description, and the District Court again granted Roche's motion. Roche also moved for summary judgment of noninfringement under the doctrine of equivalents, and the District Court granted this motion as well.
On appeal, Carnegie Mellon argued that the District Court had erred in granting Roche's motions for summary judgment of invalidity of the '708, '270, and '745 patents. Carnegie Mellon also argued that the District Court had erred in granting Roche's motions for summary judgment of noninfringement of the '708 and '745 patents.
With respect to the issue of invalidity of the '708 and '745 patents, the Federal Circuit noted that "[t]he appealed claims of the '708 patent are directed to recombinant plasmids that contain a DNA coding sequence that is broadly defined, and only by its function, viz., encoding DNA polymerase I," and further, that "the generic claims are not limited to a single bacterial species, but broadly encompass coding sequences originating from any bacterial species." The Court similarly noted that "the appealed claims of the '745 patent are broadly directed to recombinant plasmids that contain a DNA coding sequence, again, only defined by function, viz., encoding an enzyme with either DNA polymerase or nick-translation activity," and that "[t]hose claims are also not limited to a single bacterial species, but cover all bacterial species."
In addition, the Federal Circuit observed that at the time of invention, out of thousands of bacterial species, only three bacterial polA genes had been cloned, and only one of these genes had been described in the patents at issue. Moreover, despite the description in the patents that "an important feature of this invention [is] that the cloned polA gene fragment contains essentially none of or at the most only a portion of the activity of its natural promoter," the patents "fail to disclose the nucleotide sequence or other descriptive features for a polA gene (including the promoter sequence) from any bacterial source other than E. coli." As a result, the Federal Circuit concluded that no genuine issues of material fact existed as to whether the written descriptions of the '708 and '745 patents adequately support the appealed claims, and therefore, the Court affirmed the District Court's grant of summary judgment of invalidity.
With respect to the issue of invalidity of the '270 patent, the Federal Circuit determined that the District Court had erroneously found the asserted claims of this patent invalid under Gentry Gallery, Inc. v. Berkline Corp., 134 F.3d 1473 (Fed. Cir. 1998). In particular, the District Court had found the asserted claims invalid for failure to recite the problem that the invention was intended to solve (i.e., lethality). Citing Cooper Cameron Corp. v. Kvaerner Oilfield Products, Inc., 291 F.3d 1317 (Fed. Cir. 2002), the CAFC noted that it had "not announce[d] a new 'essential element' test mandating an inquiry into what an inventor considers to be essential to his invention and requiring that the claims incorporate those elements" in Gentry Gallery. However, the Federal Circuit determined that the asserted claims of the '270 patent were nonetheless invalid under Eli Lilly for the same reasons that the '708 and '745 patents were invalid.
Finally, with respect to the issue of noninfringement, the Federal Circuit noted that its affirmance of invalidity of the '708 patent rendered the issue of noninfringement of this patent moot. However, because the validity of the claims of the '745 patent that were found to be noninfringed had not been challenged, the CAFC was forced to take this issue up. On appeal, Carnegie Mellon argued that Roche's pLSG5 plasmid infringed the '745 patent under the doctrine of equivalents because the substitution of Taq polymerase for E. coli polymerase was an insubstantial and unimportant change that resulted in an infringing equivalent. In affirming the District Court's grant of summary judgment of noninfringement, the Federal Circuit determined that to find otherwise would be to vitiate the limitation of the asserted claims which required that the bacterial source of the DNA polymerase be E. coli. In particular, the CAFC stated that "in drafting the claims, the patentees specifically chose to limit claim 4 to a recombinant plasmid where the bacterial source is E. coli," and that Carnegie Mellon "cannot now argue that any bacterial source, including Taq, would infringe that claim."
(In an interesting footnote to the opinion, the CAFC noted that "Taq DNA polymerase was and continues to be integral to the success of [the] polymerase chain reaction ("PCR"), a widely used technique in molecular biology," and that Taq polymerase garnered the title of "Molecule of the Year" from Science in 1993. The Court also noted that "[w]hile we reach our decision irrespective of those facts, we readily can see why appellants have attempted to broaden the scope of their claims beyond the E. coli species disclosed.")
Carnegie Mellon University v. Hoffman-La Roche Inc. (Fed. Cir. 2008)
Panel: Circuit Judges Lourie, Bryson, and Prost
Opinion by Circuit Judge Lourie