US judge invalidates Pernix patents in Alvogen clash

Generics maker Alvogen secured a patent win at a US court last week, despite the judge finding that the company had infringed patents covering an opioid treatment.

On Friday, August 24, District Judge William Bryson concluded that while pharmaceutical company Pernix Therapeutics had proven infringement of its patents, the nine asserted claims of the patents are invalid.

Back in March 2016, Pernix sued Alvogen, accusing the generics maker of infringing six patents covering the Zohydro ER (hydrocodone bitartrate) extended-release capsule.

Pernix was responding to an Abbreviated New Drug Application submitted by Alvogen for a generic version of Zohydro.

Last week, Bryson found that Alvogen’s generic product would result in joint infringement by physicians and their patients, and that its label would induce the infringement.

Alvogen argued that the claims were obvious over Devane, a published patent application titled “Multiparticulate modified release composition”, and also in view of a patent application published in 2010 (Jain) and/or two labels for Vicodin and Lortab. Both of these products contain hydrocodone and acetaminophen in an immediate-release formulation.

Bryson found that all of the claims would have been obvious over the combination of Devane and Jain, particularly in light of the state of the art, including the two labels.

The court also found that Pernix’s written claims were generic as they are “directed to methods of treating pain by administering to patients any of an open-ended set of formulations that satisfy either the non-adjustment or the pharmacokinetic limitations of the various asserted claims”.

Alvogen was granted judgment on each of the patent claims.

Pernix said that it was disappointed with the court’s invalidity ruling and intends to appeal this aspect of the judgment.

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