Federal Circuit Affirms Obviousness Of Patents Covering Extended-Release Hydrocodone Formulations
On December 27, 2019, the Court of Appeals for the Federal Circuit (“CAFC”) issued an opinion affirming the decision of invalidity on obviousness grounds of the United States District Court for the District of Delaware. Persion Pharms. LLC v. Alvogen Malta Operations Ltd., __ F.3d __ (Fed. Cir. Dec. 27, 2019). The CAFC found no clear error in the district court’s reliance on inherency in its analysis or in its factual findings.
Persion Pharmaceuticals, LLC owns U.S. Patent Nos. 9,265,760 and 9,339,499, which claim methods of treating pain in patients with mild or moderate liver impairment using extended-release formulations of hydrocodone only, some claiming administering an unadjusted dose and others claiming administering a dose causing certain pharmacokinetic results in the patient. Persion markets Zohydro ER, which is covered by the Asserted Patents. On March 4, 2016, Persion sued Alvogen Malta Operations Ltd. for infringement of certain claims of the Asserted Patents after Alvogen filed an Abbreviated New Drug Application seeking to market a generic version of Zohydro ER.
After a bench trial, the district court found that Alvogen would indirectly infringe the asserted claims, but that the claims were invalid as obvious over U.S. Patent App. Pub. No. 2006/0240105 (“Devane”)—which disclosed using the same formulation as Zohydro ER to treat pain in normal patients—in view of additional art that disclosed the treatment of pain in patients with liver impairment. On appeal, Persion challenged the district court’s finding on four grounds.
First, Persion challenged the district court’s finding that the claimed pharmacokinetic results are inherent in any combination including Devane because they were “necessarily present” in the formulation disclosed in Devane and used in Zohydro ER. Persion argued that the district court erred in applying the inherency doctrine because Devane does not teach administering the disclosed formulation to patients with liver impairments. The CAFC found no clear error, noting that, under Par v. TWi, “inherency may supply a missing claim limitation in an obviousness analysis” where the missing limitation “is the natural result of the combination of prior art elements.” (Emphasis in original.)
Second, Persion challenged the district court’s finding that a skilled artisan would have been motivated to administer the formulation described by Devane and used in Zohydro ER to patients with mild to moderate liver impairment at an unadjusted dose and would have had a reasonable expectation of success. Persion argued the district court erred in relying on evidence that did not pertain to formulations including hydrocodone only and/or did not pertain to patients with liver impairment. The CAFC found no clear error in the district court’s factual findings.
Third, Persion argued that the district court erred in finding the asserted claims obvious before considering objective indicia of nonobviousness. The CAFC found no clear error, noting that, although the district court’s discussion of objective indicia in its order followed its discussion of obviousness, the district court “properly considered the totality of the obviousness evidence  and did not treat the objective indicia as a mere ‘afterthought.’”
Finally, Persion argued that the district court’s obviousness decision must be reversed as inconsistent with its written description decision. The CAFC found no clear error, finding that Persion’s argument relied on “incomplete quotations from the district court’s opinion” and that, when read in context, there were no inconsistencies in the district court’s obviousness and written description decisions.