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A Claim to a Genus Described in Functional Terms Was Not Supported by the Specifi cation’s Disclosure of Species That Were Not Representative of the Entire Genus

September 08, 2008

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Last Month at the Federal Circuit - October 2008

Judges: Lourie (author), Bryson, Prost

[Appealed from: N.D. Cal., Judge Illston]

In Carnegie Mellon University v. Hoffman-La Roche Inc., Nos. 07-1266, -1267 (Fed. Cir. Sept. 8, 2008), the Federal Circuit affirmed the district court’s SJ of invalidity and noninfringement in favor of Hoffman-La Roche Inc. and other defendants (collectively “Roche”).

Carnegie Mellon University (“CMU”) owns three patents relating to recombinant plasmids for the enhanced expression of an enzyme, to the preparation by gene cloning of such plasmids, to bacterial strains containing said plasmids, and to methods for the conditional control of the expression of the enzyme. The enzyme of interest is DNA polymerase I (“Pol I”), which in E. coli bacteria is encoded by the polA gene. The recombinant plasmids can express Pol I at levels high enough to facilitate isolation of Pol I. Normally, however, expression of Pol I at too high a level results in cell death. The patents disclose how to eliminate or reduce lethal unregulated expression of Pol I by either removing or damaging the polA promoter, a DNA sequence that facilitates expression of the polA gene. Throughout the specification, the patents teach that the host bacterial strain that is used is E. coli.

Roche commercially manufactures recombinant DNA polymerases. The accused product involves a recombinant plasmid, pLSG5, which causes host cells to express an enzyme known as Taq DNA polymerase. CMU and Three Rivers Biologicals, Inc. (collectively “appellants”) filed two suits against Roche, alleging that Roche’s plasmid infringed U.S. Patent Nos. 4,767,708 (“the ’708 patent”); 5,126,270 (“the ’270 patent”); and 6,017,745 (“the ’745 patent”). Roche moved for SJ that the claims in the ’708, ’270, and ’745 patents were invalid for lacking written description support, that the claims in the ’708 patent were not infringed, and that the claims of the ’745 patent were not infringed under the DOE. Roche also asserted that the patents were not enforceable due to inequitable conduct. Though the district court held that the inequitable conduct charge was not adequately supported by the evidence, the district court granted SJ of invalidity and noninfringement. On appeal, the Federal Circuit addressed the issues from both infringement suits together.

Regarding written description, the Federal Circuit noted that the appealed claims were broadly directed to recombinant plasmids that contain a DNA coding sequence defined by function. The Court also noted that the generic claims were not limited to a single bacterial species, but broadly encompassed all bacterial species.

The Court, citing Regents of University of California v. Eli Lilly & Co., 119 F.3d 1559 (Fed. Cir. 1997), explained that “to satisfy the written description requirement for a claimed genus, a specification must describe the claimed invention in such a way that a person of skill in the art would understand that the genus that is being claimed has been invented, not just a species of the genus.” Slip op. at 14. The Court also found the PTO’s Guidelines for Examination of Patent Applications under the 35 U.S.C. § 112, ¶ 1, “Written Description” Requirement (“Guidelines”) to be persuasive authority that provides further guidance for determining whether the written description requirement is met for claims drawn to a genus. Specifically, the Guidelines instruct that the written description requirement for a claimed genus may be satisfied through sufficient description of a representative number of species if the species that are adequately described are representative of the entire genus. The Guidelines also indicate that for inventions in an unpredictable art, adequate written description of a genus that embraces widely variant species cannot be achieved by disclosing only one species within the genus.

Regarding the claims of the ’708 and ’745 patents, the Court noted that, while the claims encompassed a genus of recombinant plasmids that contain coding sequences for DNA polymerase or nick-translation activity from any bacterial source, the specifications of the patents only disclosed the polA gene coding sequence from one bacterial source, E. coli. The record indicated that at the time of the invention, only three bacterial polA genes out of thousands of bacterial species had been cloned. The record also showed that Pol I was not a single enzyme, but a family of enzymes encoded by a family of genes that varied from one bacterial species to another. The Court also found it significant that the written descriptions of the ’708 and ’745 patents clearly indicated that the polA gene was critical to the claimed invention, and yet the specifications failed to disclose the polA gene-coding sequence from any other bacterial source.

The Court therefore agreed with the district court that the narrow disclosure of the E. coli polA gene was not representative of and failed to adequately support the entire claimed genus under Eli Lilly. The Court explained, “One must show that one has possession, as described in the application, of sufficient species to show that he or she invented and disclosed the totality of the genus.” Id. at 18.

The Court rejected the appellants’ argument that the district court’s decision should be reversed based on the Court’s holding in Capon v. Eshhar, 418 F.3d 1349, 1358 (Fed. Cir. 2005). In Capon, the Court explained that Eli Lilly did not impose a per se rule requiring recitation in the specification of the nucleotide sequence of claimed DNA, when that sequence was already known in the field. The Court, however, noted that in Capon, the prior art contained extensive knowledge of the involved nucleotide structure. In contrast, the record in this case showed that only three bacterial polA genes out of thousands of genes had been cloned. Thus, the Court concluded that its decision in Capon did not apply to the claims on appeal.

The Court also rejected the appellants’ argument that the district court erred by failing to consider the declarations of their experts, which, according to the appellants, created genuine issues of material fact. The Court found that the additional expert statements relied upon by the appellants were immaterial to the relevant inquiry and did not raise genuine issues of material fact. Accordingly, the Court affirmed the district court’s grant of SJ of invalidity with respect to the ’708 and ’745 patent claims.

Addressing the claims of the ’270 patent, the Court agreed with the appellants that the district court erred in finding that the claims were invalid for lack of written description under Gentry Gallery, Inc. v. Berkline Corp., 134 F.3d 1473 (Fed. Cir. 1998). The district court applied an essential element test, finding the claims were invalid because the claims did not contain an essential element of the invention. The Court explained that Gentry Gallery did not announce 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. Instead, the Gentry Gallery Court expounded upon the unremarkable proposition that a broad claim is invalid when the entirety of the specification clearly indicates that the invention is of a much narrower scope. While the district court erred in holding the claims invalid under Gentry Gallery, the Federal Circuit nonetheless concluded that these claims were invalid for lack of written description under Eli Lilly, applying the same reasoning as for the ’708 and ’745 patents.

The Court then addressed whether the remaining claims of the ’745 patent, which were not held invalid, and which recited E. coli as the bacterial source, were infringed under the DOE. The appellants argued that the substitution of Taq for E. coli as a bacterial source was an insubstantial and unimportant change that resulted in an infringing equivalent. Roche responded, stating that the appellants’ infringement argument would vitiate the E. coli claim limitation of the appealed claims. In addition, Roche argued that the differences between Taq and E. coli were not insubstantial. The Court agreed with Roche that a finding that Taq was an equivalent of E. coli would essentially render the “bacterial source [is] E. coli” claim limitation meaningless, and would thus vitiate that limitation of the claims. Accordingly, the Federal Circuit affirmed the SJ of noninfringement.