Hoffmann-La Roche, Inc. v. Promega Corp.

• Decision Date: 31 March 2003
• Docket Number: No. 00-1372.,00-1372.
• Citation: 323 F.3d 1354
• Parties: HOFFMANN-LA ROCHE, INC., and Roche Molecular Systems, Inc., Plaintiffs-Appellants, v. PROMEGA CORPORATION, Defendant-Appellee.
• Court: U.S. Court of Appeals — Federal Circuit

323 F.3d 1354

HOFFMANN-LA ROCHE, INC., and Roche Molecular Systems, Inc., Plaintiffs-Appellants, v. PROMEGA CORPORATION, Defendant-Appellee.

No. 00-1372.

United States Court of Appeals, Federal Circuit.

DECIDED March 31, 2003.

COPYRIGHT MATERIAL OMITTED

COPYRIGHT MATERIAL OMITTED

Jennifer Gordon, Pennie & Edmonds LLP, of New York, NY, argued for plaintiffs-appellants. With her on the brief were Todd A. Wagner and Todd L. Krause. Of counsel on the brief were Barbara A. Caulfield, Orrick, Herrington & Sutcliffe LLP, of San Francisco, CA. Of counsel were S. Leslie Misrock, Pennie & Edmonds; Heidi Keefe, and Myra J. Pasek, Orrick, Herrington & Sutcliffe LLP.

James R. Troupis, Michael Best & Friedrich LLP, of Madison, WI, argued for defendant-appellee. With him on the brief were Michael E. Husmann, J. Donald Best, John C. Scheller, and Karla M. Davis. Of counsel on the brief were Peter G. Carroll and Kamrin T. MacKnight, Medlen & Carroll LLP, of San Francisco, CA; and Russell L. Johnson, Skjerven, Morrill, MacPherson, Franklin & Friel LLP, of San Jose, CA.

Before NEWMAN, Circuit Judge, ARCHER, Senior Circuit Judge, and BRYSON, Circuit Judge.

Opinion for the court filed by Circuit Judge BRYSON. Dissenting opinion filed by Circuit Judge PAULINE NEWMAN.

BRYSON, Circuit Judge.

I

The polymerase chain reaction (PCR) allows scientists, beginning with a small amount of deoxyribonucleic acid (DNA), to generate many copies of that DNA in a short period of time. The ability of PCR to synthesize DNA rapidly has led to significant advances in molecular biology and has been particularly useful in pathology and in the identification of trace materials such as blood and hair.

In the first stage of PCR, a segment of DNA is separated at high temperature into its two component strands. Then, at a lower temperature, small pieces of synthetic DNA called "primers" are annealed to specific locations on the separated strands. Enzymes known as DNA polymerases then "extend" the primers by attaching a complementary nucleotide to each nucleotide in the template strand. In this manner, the polymerase creates two identical double-stranded DNA helices from the two separated single strands of the original helix. The process of strand separation, primer annealment, and extension is then performed repeatedly, resulting in the production of a large number of identical DNA strands.

When PCR was first developed, the high temperatures associated with strand separation destroyed the polymerase that was used to drive the reaction. Accordingly, new polymerase had to be added at the beginning of each cycle of the reaction, which was cumbersome. It was subsequently discovered that the DNA polymerase of the Thermus aquaticus, or "Taq," bacterium, which is found in geysers and hot springs, was stable and active at high temperatures and therefore could withstand the rigors of PCR. Thus, Taq needed to be added to the reaction mixture only once, which resulted in making the PCR process much faster and more efficient.

On June 17, 1987, Cetus Corporation, the predecessor of appellants Hoffmann-La Roche, Inc., and Roche Molecular Systems, Inc. (collectively, "Roche"), filed U.S. Patent Application No. 07/063,509 ("the '509 application"), which was directed to a purified thermostable enzyme. The '509 application named Dr. David Gelfand, the Cetus scientist most knowledgeable about the Taq enzyme, and Ms. Susanne Stoffel, Dr. Gelfand's technician, as inventors. The broadest originally filed claim was not limited to the Taq enzyme.

In an office action dated November 1, 1988, the examiner rejected all the submitted claims on a variety of grounds. The rejections included an anticipation/obviousness rejection based on journal articles by Chien, et al., and Kaledin, et al., both of which disclosed a DNA polymerase derived from the Taq bacterium. The examiner noted that the applicants included molecular weight limitations in dependent claims and that those limitations differed from the estimates of Taq's molecular weight reported by Chien and Kaledin. The examiner suggested that "some proteins behave anomalously when subjected to SDS page," the technique used by the applicants to estimate molecular weight. For that reason, the examiner concluded that "[i]t is not clear whether or not the molecular weight an[d] pH range of activity claimed by applicants for the instant enzyme is a result of experimental parameters or an enzyme activity different than the [enzyme] previously described in the literature."

On March 17, 1989, the inventors responded to the examiner's rejection, canceling all pending claims and entering three new claims, the broadest of which provided as follows:

1. Purified thermostable Thermus aquaticus DNA polymerase that migrates on a denaturing polyacrylamide gel faster than phosphorylase B and more slowly than does bovine serum albumin and has an estimated molecular weight of 86,000-90,000 daltons when compared with a phosphorylase B standard assigned a molecular weight of 92,500 daltons.

U.S. Patent No. 4,889,818, col. 44, ll. 46-52.

In remarks accompanying the amendment, the applicants made a two-part argument for patentability. First, they asserted that the claimed enzyme was distinct from the prior art enzyme, citing differences in molecular weight, specific activity, and fidelity. Second, they contended that even if, contrary to their belief, the claimed and prior art enzymes were identical, the claimed enzyme would still be patentable because it was "far more pure" than the enzyme of the Chien and Kaledin preparations. To support that assertion, the inventors cited a portion of the application indicating that the claimed enzyme had a specific activity ten times that of the prior art enzyme.

The examiner allowed the amended claims without further comment. The '509 application therefore issued as U.S. Patent No. 4,889,818 ("the '818 patent") on December 26, 1989.

Cetus licensed the '818 patent to Promega Corporation in June 1990. After Cetus sold the '818 patent to Roche, Promega allegedly breached the license agreement. Roche filed suit, alleging patent infringement and breach of contract. Promega counterclaimed, asserting inter alia that the '818 patent was unenforceable due to inequitable conduct, a claim that soon became the focus of the litigation.

In August 1996, the district court held on summary judgment that the inventors had made four material misrepresentations during the prosecution of the '818 patent. After a bench trial, the court held that the `818 patent was unenforceable based on eight separate misrepresentations and omissions, including three of the ones the court had addressed at the summary judgment stage. Roche appeals the court's order holding the patent unenforceable.

II

A party seeking to have a patent declared unenforceable has a heavy burden to meet. Inequitable conduct requires misrepresentation or omission of a material fact, together with an intent to deceive the PTO. Both of those distinct elements must be shown by clear and convincing evidence. See Manville Sales Corp. v. Paramount Sys., Inc., 917 F.2d 544, 552, 16 USPQ2d 1587, 1593 (Fed.Cir.1990); Kingsdown Med. Consultants, Ltd. v. Hollister Inc., 863 F.2d 867, 872, 9 USPQ2d 1384, 1389 (Fed.Cir.1988). Once the requisite levels of materiality and intent are shown, the district court must determine whether the equities warrant a conclusion that the patentee has engaged in inequitable conduct. Molins PLC v. Textron, Inc., 48 F.3d 1172, 1178, 33 USPQ2d 1823, 1827 (Fed.Cir.1995).

While it is difficult to prove inequitable conduct, a district court's ruling on inequitable conduct is reviewed deferentially. The court's findings on materiality and intent are reviewed for clear error, and thus will not be overturned in the absence of a "definite and firm conviction" that a mistake has been made. Molins, 48 F.3d at 1178, 33 USPQ2d at 1827. The district court's assessment of the equities is reviewed for an abuse of discretion. Id.

The district court in this case based its inequitable conduct ruling on its finding that the inventors made various material misrepresentations and related omissions, which can be grouped into three categories: (1) representations regarding the difference in molecular weight between the claimed and prior art Taq enzymes; (2) representations that the inventors had performed Example VI, one of the procedures described in the specification, and that they had achieved the described results; and (3) representations concerning the comparative fidelity and template dependence of the claimed enzyme and the prior art enzymes.

We analyze each of the three categories of asserted inequitable conduct below, upholding the district court's findings as to two of the three and overturning the court's findings as to the third. The dissent, which would overturn the district court's findings with respect to all three categories, criticizes us for failing to apply the clear and convincing standard of proof in assessing the evidence of materiality and intent. While we recognize the standard of proof that applies to those factual issues, we also note that our task as a reviewing court is not to make those factual determinations in the first instance but to determine whether the district court's findings on those issues are clearly erroneous or are infected with legal error. With that standard of review in mind, we turn to each of the grounds on which the district court based its ruling.

A. Molecular Weight

In their response to the examiner's office action, the inventors argued that the claimed enzyme was different from the enzyme described in the cited references. Their argument focused principally on the disparity in the molecular weight values reported for the prior art enzymes and the claimed enzyme. The inventors noted that claim 1 of the '509 application recited an enzyme with a molecular weight of 86,000 to 90,000 daltons, while the Chien...