Horizon Pharma files Duexis patent lawsuit against Par

DEERFIELD — Horizon Pharma filed a lawsuit against Par Pharmaceutical, claiming Par’s intention to market a generic version of Horizon’s arthritis drug Duexis violates Horizon’s patents.

The lawsuit, filed in U.S. District Court in Delaware, said Par filed a new drug application with the Food and Drug Administration to market a generic version of Duexis, claiming its version would not be in conflict with Horizon’s patents on the drug. Horizon claims Par did not advise them to the timing or status of the FDA’s review of its filing, or whether it has complied with FDA requirements for proving it doesn’t violate Pharma’s patents. Duexis is used to treat osteoarthritis and rheumatoid arthritis,

Horizon said it filed the lawsuit within the 45 days required to automatically bar the FDA from approving Par’s request for 30 months or until a district court decision that is adverse to the patent.