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Federal Circuit Affirms Priority Victory for Aventis Pharma S.A.

October 22, 2003
Irving, Thomas L.

Decision icon Decision

Last Month at the Federal Circuit - November 2003

Judges: Lourie (author), Schall, and Newman (dissenting-in-part)

In Chen v. Bouchard, No. 03-1037 (Fed. Cir. Oct. 22, 2003), the Federal Circuit affirmed the Board’s ruling that the party Bouchard (Aventis Pharma S.A.) prevailed on all counts of a patent interference against the party Chen (Bristol-Myers Squibb Company). The interference involved a class of taxanes, anticancer agents, characterized as “7,8-cyclopropataxols” or, more generally, “cyclopropataxols”).

The Chen patent-in-interference and Bouchard application-in-interference claimed substantially the same patentable subject matter set forth in three separate counts: a count for generic 7,8-cyclopropataxols; a count for a 7,8-cyclopropataxol species; and a count for 7,8- cyclopropabaccatin intermediates for making 7,8-cyclopropataxols. For all three counts, the parties did not dispute Bouchard’s entitlement to its French foreign priority date of invention (“Bouchard’s priority date”). Chen asserted that the Chen inventors, Drs. Chen and Farina, made cyclopropataxols falling within two of the counts before Bouchard’s priority date and that Chen is entitled to rely on the July 1, 1992, date of its first-filed application, U.S. Application Serial No. 07/907,261, for all counts, including the 7,8-cyclopropataxol species.

The nub of the Board’s decision was that Chen failed to prove, prior to Bouchard’s priority date, that they had (1) contemporaneously established the chemical identities of any cyclopropataxols, as needed for actual reduction to practice; and (2) filed any patent application disclosing that they discovered cyclopropataxols, as needed for constructive reduction to practice, but instead disclosed and claimed only fluorotaxol compounds in the July 1, 1992, application. Finding the Board’s decision to be supported by substantial evidence and not contrary to law, the Federal Circuit affirmed.

The Board and Court found no explicit or inherent disclosure of the cyclopropataxol compounds of the counts in Chen’s priority applications. As for inherency, the Court rejected Chen’s argument that it makes no difference that Chen specified only fluorotaxol compounds since the underlying work actually produced cyclopropataxol compounds. One skilled in the art would find no indication in the Chen priority specifications or otherwise appreciate that the reference to fluorotaxol was incorrect. In those circumstances, the Court was unwilling to accept Chen’s inherency argument, discard the disclosure of fluorotaxol, and replace it by cyclopropataxol.

The Federal Circuit therefore concluded that the priority applications did not describe the cyclopropataxol compounds and could not be accorded priority benefit. Hence, Chen was not awarded a constructive reduction to practice for the compound of any count.

Regarding actual reduction to practice, the Federal Circuit rejected the Board’s noncorroboration holding to the extent it suggested that an analytical chemist must be “kept in the dark” as to what the inventor believes about a compound’s structure. However, the Court found any error harmless because Chen failed to prove its case.

Bouchard pointed out that to establish adequate identification for actual reduction to practice purposes, Chen relied on the same analytical techniques that led to a firm, but incorrect, conclusion that the priority applications formed mixtures of fluorotaxol compounds. The Board found that Chen produced no evidence establishing how Chen identified any compounds within the counts or how the analytical data obtained by the analytical chemists to whom the inventor sent his compounds for analysis confirm the structures suggested by the inventor. Rather, Chen relied only on attorney arguments and conclusory proclamations that the data obtained were “consistent” with the inventor’s suggestions.

The Board found that these and numerous other findings of the Board provided substantial evidence to conclude that Chen failed to prove an actual reduction to practice before Bouchard’s priority date. Hence, Chen was not awarded an actual reduction to practice for any compound within any count.

Finally, the Federal Circuit found that the Board did not abuse its discretion by excluding hearsay and unauthenticated evidence and that substantial evidence demonstrated that there was no conception, prior to Bouchard’s priority date, coupled with diligence, leading to a reduction to practice.

Consequently, the Court affirmed the Board’s decision to award judgment to Bouchard with respect to all three counts.

Judge Newman, dissenting, took issue with the exclusion of evidence and also concluded that Chen had established prior actual reduction to practice.

[At the Federal Circuit, Tom Irving, a partner in our firm, argued for Bouchard. With him on the brief were Herb Mintz, Tim Donaldson, Sanya Sukduang, and Esther Lim.]