Horizon Pharma sues Par for infringing Duexis patent

Horizon Pharma (Nasdaq: HZNP) has filed a patent infringement lawsuit in the US District Court for the District of Delaware against fellow USA-based Par Pharmaceutical (NYSE: PRX) and related to an Abbreviated New Drug Application that Par filed with the Food and Drug Administration to market a generic version of Duexis (ibuprofen and famotidine) tablets.

The law suit claims infringement of Horizon's US patent 8,067,033 that is listed in the FDA's Orange Book and expires July 18, 2026. Horizon received a Paragraph IV Patent Certification from Par on February 15, 2012, advising that it had filed an ANDA with the FDA for a generic version of Duexis tablets. Par alleged that its generic version of the tablets would not infringe US patent 8,067,033 or the patent is invalid or unenforceable.

Par has not advised Horizon as to the timing or status of the FDA's review of its filing, or whether it has complied with the agency’s requirements for proving bioequivalence.