Under 102(g), Conception of Prior Art Requires Appreciation of Invention

Invitrogen Corp. v. Clontech Laboratories (Fed. Cir. 2005).

By Donald Zuhn, Ph.D. (Patently-O Guest Author).

In an appeal from a District Court judgment invalidating more than two hundred claims in three Invitrogen patents as being anticipated under § 102(g)(2), the Federal Circuit vacated and remanded, holding that the District Court misapplied the law of appreciation when determining the date of conception for researchers at Columbia University. The Federal Circuit, however, affirmed the District Court’s rulings on enablement, written description, and infringement.

The patents at issue relate to a genetically modified version of the enzyme reverse transcriptase, that has use in the field of molecular biology. Naturally-occurring (or unmodified) reverse transcriptase possesses both DNA polymerase and RNase H activities, the former permitting the enzyme to synthesize a DNA copy (cDNA) of a messenger RNA (mRNA) template, and the latter permitting the enzyme to degrade the mRNA template following cDNA synthesis. In contrast, the genetically modified enzyme lacks RNase H activity, and therefore, is unable to degrade the mRNA template following cDNA synthesis, allowing researchers to reuse the mRNA template to create additional cDNA copies..

While neither party disputed the District Court’s determination that Invitrogen had reduced a modified reverse transcriptase lacking RNase H activity to practice in January of 1987, Invitrogen did find fault with the lower court’s ruling that Drs. Stephen Goff and Naoko Tanese, two researchers at Columbia University, had conceived of such an enzyme before Invitrogen had reduced the enzyme to practice. Drs. Goff and Tanese had begun their work in 1984 by preparing a panel of bacterial mutants having modified reverse transcriptase genes. The panel included two mutants that the Columbia University researchers would later show possess modified reverse transcriptase lacking RNase H activity. However, due to limitations in the assays that Drs. Goff and Tanese were using to measure RNase H activity, they were unable to conclusively establish that any of the mutants possessed modified reverse transcriptase lacking RNase H activity at the time the mutant panel was prepared. In March of 1987, Drs. Goff and Tanese used a new assay that they had developed to finally establish that two of the mutants from their panel possessed the modified enzyme. They were also able to correlate the results obtained with their new assay with their late 1986 sequencing analysis of the mutants.

Following a series of pre-trial motions regarding the issues of conception, enablement, written description, and infringement, the District Court determined, inter alia, that Drs. Goff and Tanese (a) had conceived of a genetically modified reverse transcriptase lacking RNase H activity either in December of 1984 when they had isolated mutants possessing modified reverse transcriptase, or in January of 1986 when they had sequenced the reverse transcriptase genes in these mutants; (b) had actually reduced their invention to practice in March of 1987 when they established that two mutants from their panel possessed modified reverse transcriptase; and (c) were diligent in reducing their invention to practice, and did not abandon, conceal, or suppress it. However, despite these rulings, the District Court refused to find that the work of Drs. Goff and Tanese anticipated Invitrogen’s patents under § 102(g)(2), arguing that anticipation posed factual questions requiring resolution on a claim by claim basis.

Stating that conception “require[s] more than unrecognized accidental creation,” and instead “requires that the inventor appreciate that which he has invented,” the Federal Circuit found that the District Court erred by establishing Drs. Goff and Tanese’s conception before January of 1987 and granting partial summary judgment for Clontech. Relying on decisions of its predecessor Court, which “require some connection between the physical result (the invention) and the belief (by the inventor),” the Federal Circuit determined that the record was inconsistent with the District Court’s notion that Drs. Goff and Tanese set out to create a modified reverse transcriptase or appreciated in 1984 that their mutant panel contained two mutants possessing modified reverse transcriptase. Rather, the Federal Circuit believed that this case “fit[] squarely within the unrecognized, accidental duplication cases.”

However, while the Federal Circuit determined that the evidence excluded both dates of conception proposed by the District Court, the Federal Circuit also found that Dr. Goff’s deposition testimony precluded it from finding that the District Court abused its discretion in refusing to grant partial summary judgment for Invitrogen on the issue of conception. In particular, Dr. Goff had testified that he had formed a suspicion in late 1986, based on his difficulties analyzing the mutants, that two of the mutants possessed modified reverse transcriptase lacking RNase H activity. Because a reasonable fact-finder presented with Dr. Goff’s testimony could conclude that the evidence preceding the researchers’ March 1987 testing might suffice, under the applicable standard, to corroborate Dr. Goff’s suspicions about the two mutants, the Federal Circuit vacated the District Court’s invalidity judgment and remanded the case for further proceedings.

NOTE: This post was written by patent attorney Donald Zuhn, PhD. Don is a true expert in cutting edge biotech patent law and practices both litigation and prosecution at MBHB LLP in Chicago. (zuhn@mbhb.com).