In Ajinomoto Co., Inc. v. Intl. Trade Commn., 932 F.3d 1342 (Fed. Cir. 2019), the Federal Circuit affirmed an equivalents determination by the USITC. When I wrote about the case back in August, I coined the catchy acronym: DoEPHETAN.
DoEPHETAN: the Doctrine of Equivalents limited by Prosecution History Estoppel unless the narrowing amendment is “merely tangential” to the equivalent in question.
Yes – this is awful. Its not me; Lets blame the courts who wanted to empower patentees with the doctrine of equivalents but then became afraid that they had gone too far.
In Ajinomoto, the Federal Circuit found that the patentee had found its way through the DoEPHETAN maze. As originally filed, the patent claims covered the accused genetically engineered E. coli. During prosecution the claims were narrowed to avoid a particular prior art references. However, the accused bacteria is also different from the amended-around prior art and so the Federal Circuit found the amendment merely tangential to the equivalent and therefore did not bar the patentee from relying upon the Doctrine of Equivalents. In the original decision, the majority (Judges MOORE and TARANTO) sided with the patentee while Judge DYK dissented in part.
In recent filings, the adjudged infringer (CheilJedang) asked for rehearing — arguing that the majority “applied an expansive approach” the “merely tangential” exception rather than the proscribed “very narrow” application.
The new approach, moreover, accepts post hoc “prosecution-remorse” arguments and threatens to vitiate PHE by expanding the exception well beyond its historical application.
Despite a well written brief, the Federal Circuit has now denied the en banc petition without opinion — leaving this discussion for another day.
I do think that the petition is correct — the majority opinion here appears to be a signal of a slight expansion of DoE. Time will tell whether patentees take advantage.
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I though this list (below) was interesting from the brief. In the litigation, 15 Ropes & Gray attorneys have represented the accused infringer (CJ). Of those, 9 are no longer at the firm.
The petition was filed by Steven Pepe & Matthew J. Rizzolo at Ropes & Gray along with James Haley from Haley Guiliano. The list below are attorneys not on this brief, but who have represented CJ in the case that was filed in 2016.