doctrine of equivalent : CAFC Alert

The disclosure-dedication doctrine applies at limitation level, not at embodiment level

| May 27, 2020

Eagle Pharmaceutical Inc. v. Slayback Pharm LLC

May 8, 2020

O’Malley (Opinion author), Reyna, and Chen

The Federal Circuit affirmed the district court’s holding that the disclosure-dedication doctrine applies here to bar application of the doctrine of equivalents and, accordingly, the Slayback’s generic products do not infringe the Eagle’s four patents.
Slayback filed new drug application (“NDA”) for a generic version of Eagle’s branded bendamustine product, BELRAPZO®. Bendamustine is used to treat chronic lymphocytic leukemia and indolent B-cell non-Hodgkin lymphoma. Eagle sued Slayback for infringing four patents in the District Court for the District of Delaware. Eagle’s four asserted patents share essentially the same written description. One of the four patents is U.S. Patent No. 9,572,796 (“the ’796 patent”), which has a representative claim 1 as shown below:

1. A non-aqueous liquid composition comprising: bendamustine, or a pharmaceutically acceptable salt thereof;
a pharmaceutically acceptable fluid comprising a mixture of polyethylene glycol and propylene glycol, wherein the ratio of polyethylene glycol to propylene glycol in the pharmaceutically acceptable fluid is from about 95:5 to about 50:50; and
a stabilizing amount of an antioxidant;
. . . .

In the district court, Slayback conceded that its generic product literally infringes all limitations of claim 1 except for the “pharmaceutically acceptable fluid” limitation. Slayback uses ethanol instead of propylene glycol (PG) in its generic product. Eagle argued that the ethanol in Slayback’s product is insubstantially different from the propylene PG in the claimed composition and, accordingly, Slayback’s product infringes under the doctrine of equivalents.
Slayback moved for a judgment of non-infringement on the pleadings under Federal Rule of Civil Procedure 12(c). Slayback argued that the disclosure-dedication doctrine barred Eagle’s claim of infringement under the doctrine of equivalents because the asserted patents disclose, but do not claim, ethanol as an alternative solvent to PG. Eagle counter-argued that the disclosure-dedication doctrine does not apply here because the asserted patents do not disclose ethanol as an alternative to PG for the claimed embodiment that contains an antioxidant. In fact, the specification only discloses ethanol when discussing unclaimed embodiments that contain chloride salt. Specifically, the asserted patents disclose three distinct “categories” of bendamustine formulations: (i) chloride salt formulations; (ii) antioxidant formulations; and (iii) dimethyl sulfoxide (“DMSO”) formulations. The specification only discloses ethanol as an alternative to PG when discussing the unclaimed chloride salt formulations; and it never discloses ethanol as an alternative to PG when discussing the claimed antioxidant formulations. Eagle also submitted an expert declaration from Dr. Mansoor Amiji in support of its opposition. Nevertheless, the district court held for Slayback because the asserted specification expressly and repeatedly identifies “ethanol” as an alternative “pharmaceutically acceptable fluid” to PG.
The federal circuit affirms the district court’s holding. The disclosure-dedication doctrine does not require the specification to disclose the allegedly dedicated subject matter in an embodiment that exactly matches the claimed embodiment. Instead, the disclosure-dedication doctrine requires only that the specification disclose the unclaimed matter as an alternative to the relevant claim limitation. That is, the disclosure-dedication doctrine requires disclosure of alternatives only at limitation level, not at embodiment level. In this case, the asserted patents disclose ethanol as an alternative to PG in the “pharmaceutically acceptable fluid” claim limitation. The specification repeatedly identifies—without qualification—ethanol as an alternative pharmaceutically acceptable fluid. Aside from the description of certain exemplary embodiments, nothing in the specification suggests that these repeated disclosures of ethanol are limited to certain formulations, or that they cannot extend to the claimed formulation.
Eagle also challenges the district court’s decision from the procedural grounds. Eagle argues that the district court erred by resolving that factual dispute at the pleading’s stage without drawing all reasonable inferences in Eagle’s favor. The federal circuit held that the district court has discretion to consider evidence outside the complaint for purposes of deciding whether to accept that evidence and convert the motion into one for summary judgment. In this case, the district court decided that Eagle was trying to fabricate a factual dispute and Slayback is entitled to judgment in its favor as a matter of law.

Take away

  1. The disclosure-dedication doctrine applies at limitation level, not at embodiment level.
  2. A patent drafter should be careful that the scopes of claims are consistent with the disclosure of specification to avoid inadvertent disclosure-dedication.

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