Eagle Pharm. Inc. v. Slayback Pharma LLC - 958 F.3d 1171 (Fed. Cir. 2020)

Rule:

The disclosure-dedication doctrine bars application of the doctrine of equivalents. It states that when a patent drafter discloses but declines to claim subject matter, this action dedicates the unclaimed subject matter to the public. By preventing a patentee from recapturing unclaimed subject matter, the disclosure-dedication doctrine reinforces the primacy of the claims in defining the scope of the patentee's exclusive right. To determine whether the disclosure-dedication doctrine applies in a given case, we ask whether the specification discloses unclaimed subject matter with such specificity that one of ordinary skill in the art could identify the subject matter that had been disclosed and not claimed. If the court concludes that the inventor dedicated an alleged equivalent to the public, the patent owner cannot prevail on its doctrine of equivalents infringement claim based on that equivalent.

Facts:

Eagle Pharmaceuticals Inc. (“Eagle”) filed the suit in the U.S. District Court for the District of Delaware accusing Slayback Pharma LLC (“Slayback”) of infringing four patents under the doctrine of equivalents. Eagle's infringement claims stemmed from Slayback's new drug application ("NDA") for a generic version of Eagle's branded bendamustine product, BELRAPZO®. J.A. 105. Eagle's four asserted patents shared essentially the same written description and all independent claims recited essentially the same limitations. Slayback conceded that its generic product literally infringed all claim limitations except for the "pharmaceutically acceptable fluid" limitation. Eagle asserted that Slayback's product infringed the "pharmaceutically acceptable fluid" limitation under the doctrine of equivalents. Specifically, Eagle asserted that the ethanol in Slayback's product was insubstantially different from the propylene glycol ("PG") in the claimed composition. In 2019, 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 disclosed, but did not claim, ethanol as an alternative solvent to PG. The district court granted Slayback's motion for judgment of non-infringement on the pleadings. The court determined that the parties had not identified a claim construction dispute, and the written description of the asserted patents unambiguously and repeatedly identified ethanol as an alternative to propylene glycol. The court concluded that it had sufficient context to decide a question of law—i.e., that the disclosure-dedication doctrine applied to bar Eagle’s claims for infringement under the doctrine of equivalents. Eagle timely appealed. 

Issue:

Did the district court err in granting Slayback's motion for judgment of non-infringement on the pleadings? 

Answer:

No.

Conclusion:

The court affirmed the district court’s decision to grant Slayback's motion for judgment of non-infringement on the pleadings because the district court did not err when it concluded that the asserted patents disclosed, but did not claim, ethanol—and therefore dedicated ethanol to the public. Moreover, the court held that the district court did not improperly apply the dedication-disclosure doctrine at the pleadings stage. The only reasonable inference that could be made from the patent disclosures was that a skilled artisan would understand the patents to disclose ethanol as an alternative to the claimed propylene glycol.