ENDO PHARMACEUTICALS INC., v. ACTAVIS LLC

ENDO PHARMACEUTICALS INC., v. ACTAVIS LLC, Appeal No. 2018-1054 (Fed. Cir. May 3, 2019).  Before Wallach, Clevenger and Stoll.  Appealed from D. Del. (Judge Andrews). (Claim Construction)

Background:

Endo sued several drug manufacturers that had filed Abbreviated New Drug Applications to market generic versions of the patented drug oxymorphone, which was licensed to Endo.  Representative claim 1 recites: “A hydrochloride salt of oxymorphone comprising less than 0.001% of 14-hydroxymorphinone.”

The district court construed the claim term “14-hydroxymorphinone” to mean “14-hydroxymorphinone hydrochloride” when read in view of the specification and based on testimony from Actavis’s expert.  This claim construction barred prior art disclosing the non-salt form of 14-hydroxymorphinone from being applied to the asserted claims.  The district court also found that a person of ordinary skill in the art would not have a reasonable expectation of success in combining the prior art, despite an FDA communication mandating that opioid manufacturers reduce ABUK impurities (which include 14-hydroxymorphinone) in oxymorphone to below 0.001%.  The district court subsequently ruled that the asserted claims were valid and had been infringed, which the defendant drug manufacturers appealed.

Issues/Holdings:

(i) Did the district court err in its claim construction?

(ii) Did the district court err in holding that the claimed composition was not obvious? (continue reading)

Summary by:  Patrick Gildea

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