Amgen's Legal Battle With Regeneron and Sanofi
The patent battle continues from PCSK9 dispute in which Amgen won at trial court level to force Sanofi and Regeneron to pull Praluent off market. Sanofi and Regeneron appealed to the U.S. Federal Circuit Court, but if the appeal stands and Amgen doesn't settle for cash, Praluent will be pulled.
Earlier this month, Amgen sued Sanofi and Regeneron for patent infringement. Sanofi and Regeneron recently received FDA approval for Dupixent (dupilumab) indicated for atopic dermatitis. Though Amgen has no competitive drugs on market or in pipeline against Dupixent, it's reciting the complaint that Dupixent violates patent '487 on using antibodies that bind to IL-4R, which Amgen owns through its subsidiary Immunex.
Unlike the PCSK9 conflict, Amgen isn't pushing for an injuction to get Dupixent off market. Amgen hasn't made any comments about its end game. Companies suing for payments and royalties are not uncommon and can be seen in seen recent debate between Merck & Co and Gilead over hepatitis C intellectual property. However, an injunction to push a drug off market is uncommon and Amgen drew a lot of criticism from other drug makers and law experts.
Source: http://www.fiercepharma.com/pharma/amgen-already-pcsk9-offense-slaps-sanofi-regeneron-dupixent-patent-suit
More info: http://blogs.harvard.edu/billofhealth/2017/01/06/lets-all-worry-about-the-effects-of-patent-injunctions-against-drug-manufacturers/