Fed Circuit affirms generic maker’s win over Eagle

The US Court of Appeals for the Federal Circuit has affirmed a generic maker’s victory over pharmaceutical company  Eagle Pharmaceuticals in a case involving cancer drug Belrapzo (bendamustine hydrochloride injection).

In a  precedential opinion handed down on Friday, May 8, the Federal Circuit rejected Eagle’s appeal against a decision of the US District Court for the District of Delaware which dismissed Eagle’s patent infringement suit.

Eagle sued  Slayback Pharma for infringing four patents covering Belrapzo under the doctrine of equivalents, after Slayback filed a new drug application for a generic version of the drug.

Slayback conceded that its generic product literally infringed all claim limitations except for the “pharmaceutically acceptable fluid” limitation.

However, Eagle asserted that Slayback’s product infringed the “pharmaceutically acceptable fluid” limitation under the doctrine of equivalents, arguing that the ethanol in Slayback’s product is insubstantially different from the propylene glycol (PG) in the claimed composition.

Slayback argued that the disclosure-dedication doctrine barred Eagle’s claim of infringement because the asserted patents disclose, but do not claim, ethanol as an alternative solvent to PG.

The disclosure-dedication doctrine, which states that “when a patent drafter discloses but declines to claim subject matter, ... this action dedicates the unclaimed subject matter to the public”, bars application of the doctrine of equivalents.

In May 2019, the district court granted Slayback’s motion for judgment of non-infringement.

On appeal against the decision, Eagle argued that the district court committed two errors when it concluded that the dedication-disclosure doctrine barred Eagle’s claim of infringement under the doctrine of equivalents.

Eagle argued that the lower court erred in concluding that the disclosure-dedication doctrine barred its infringement claims under the doctrine of equivalents. It claimed that the disclosure-dedication doctrine doesn’t apply because the patents don’t disclose ethanol as an alternative to PG.

“The specification repeatedly identifies—without qualification—ethanol as an alternative pharmaceutically acceptable fluid,” said the Federal Circuit, when rejecting Eagle’s argument.

Eagle also claimed that the Delaware court had improperly applied the dedication- disclosure doctrine at the pleadings stage, in the presence of a factual dispute (whether a skilled artisan would understand the specification to disclose ethanol as an alternative to PG in the claimed invention).

Again, the Federal Circuit sided with the lower court, finding that the “only reasonable inference” that can be made from the patent disclosures is that a skilled artisan would understand the patents to disclose ethanol as an alternative.

The court concluded: “As a result, even when viewing the pleadings in the light most favourable to Eagle, we conclude there is no material issue of fact to resolve and Slayback is entitled to judgment in its favour as a matter of law.”

Did you enjoy reading this story?  Sign up to our free daily newsletters and get stories sent like this straight to your inbox.