Finding that inherency can be used to show the presence of a missing claim limitation, the US Court of Appeals for the Federal Circuit affirmed a district court decision that asserted claims in pain management method patents were invalid as obvious. Persion Pharmaceuticals LLC v. Alvogen Malta Operations Ltd., Case No. 18-2361 (Fed. Cir., Dec. 27, 2019) (Reyna, J.).

Persion has US Food and Drug Administration (FDA) approval for its extended release hydrocodone product, Zohydro ER, and also owns two patents directed to methods of treating pain with extended release hydrocodone in patients with mild to moderate hepatic impairment. Persion sued Alvogen for infringement of certain claims in these two patents after Alvogen filed an Abbreviated New Drug Application (ANDA) requesting approval from the FDA to market a generic version of Zohydro ER. The asserted claims include: (i) non-adjustment claims directed to administering a dose of hydrocodone to patients with mild to moderate hepatic impairment without adjusting the dose relative to a healthy liver patient, and (ii) pharmacokinetic claims directed to pharmacokinetic parameters achieved after treatment with hydrocodone.

(more…)