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Mycogen’s Petition for Rehearing Denied

August 14, 2001

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Last Month at the Federal Circuit - September 2001

Judges: Bryson (author), Clevenger, and Linn

In Mycogen Plant Science, Inc. v. Monsanto Co., No. 00-1127 (Fed. Cir. Aug. 14, 2001), the Federal Circuit denied a petition for rehearing, holding that the Plaintiff was estopped from relying on the DOE under the recent en banc decision in Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558 (Fed. Cir. 2000), cert. granted, 121 S. Ct. 2519 (2001).

Mycogen Plant Science, Inc. (“Mycogen”) charged Monsanto Company (“Monsanto”) with infringement under the DOE of two claims of Mycogen’s U.S. Patent No. 5,380,831 (“the ‘831 patent”). The Federal Circuit had previously held that Mycogen was barred from relying on the DOE under prosecution history estoppel. In its petition for rehearing, Mycogen contended that the panel misunderstood the prosecution history of the ‘831 patent, thus mistakenly concluding that the asserted claims, claims 13 and 14, had no range of equivalents. The Federal Circuit disagreed after a thorough review of the prosecution
of the ‘831 patent.

As originally filed, the ‘831 patent included independent claim 1 and dependent claims 3 and 4. Independent claim 1 claimed a broad range of genes encoding a particular insecticidal protein. Claims 3 and 4 claimed a particular insecticidal gene, the sequence of which was described in Figure 1 of the specification. The Examiner rejected those claims, in part on enablement grounds, and, after considering Mycogen’s arguments, issued a final rejection.

In response, Mycogen filed a continuation application narrowing the scope of independent claim 1 and, in turn, dependent claims 3 and 4. Nevertheless, the Examiner once again rejected Mycogen’s claims, again on enablement. Specifically, the Examiner argued that the application only enabled the gene sequence disclosed in Figure 1 of the specification.

Mycogen continued prosecuting its application, twice narrowing claims 1, 3, and 4. Finally, based on the Examiner’s insistence that all claims should be limited to the gene sequence shown in Figure 1 of the specification, Mycogen amended claims 3 and 4 to be independent claims and limited those claims to only the specific sequence disclosed in Figure 1. Claims 3 and 4 were allowed as claims 13 and 14 of the ‘831 patent.

The Federal Circuit concluded that, as in Festo, Mycogen’s incorporation of limitations from dependent claims into independent claims was tantamount to a narrowing amendment. Specifically, the Court held that the limitations at issue were in dependent claims and were later incorporated into independent claims. According to the Federal Circuit, under those circumstances, Mycogen was appropriately limited to the literal scope of its claims and barred from reliance on the DOE.