Generic drugmaker Actavis Inc. said Tuesday it has filed an application with federal regulators to market a generic version of the anti-inflammatory drug Rayos.
Rayos is currently marketed by Horizon Pharma to treat rheumatoid arthritis and other inflammatory conditions.
Actavis said in a statement that Horizon Pharma AG and partner Jagotec AG filed suit against Actavis on Monday, seeking to block Actavis from launching a generic version before the expiration of certain drug patents.
Branded drugmakers routinely sue their generic competitors to attempt to block the launch of cheaper versions of their drugs. Under federal law, the lawsuits triggers a hold on approval by the FDA of up to 30 months.
Actavis shares closed down $3.72, or 2.8 percent, at $131.43.