* Horizon’s patent on Duexis expires July 18, 2026
* Shares up 5 pct in extended trade
March 28 (Reuters) - Drugmaker Horizon Pharma Inc said it filed a patent infringement lawsuit against Par Pharmaceutical Inc, seeking to block a generic version of its arthritis tablet Duexis.
In the lawsuit, Horizon alleged Par infringed its patent on the drug when it filed with the U.S. health regulator to get approval for a copy of Duexis.
Horizon Pharma’s patent on Duexis expires on July 18, 2026. The drug competes with Bristol Myers Squibb Co’s Orencia.
Shares of Horizon Pharma jumped as much as 5 percent to $3.70 in extended trade. They closed at $3.54 on Wednesday on the Nasdaq.