On February 21, 2019, Sandoz Inc. (“Sandoz”) filed suit against Amgen Inc. and Amgen Manufacturing Limited (collectively “Amgen”) seeking declaratory judgment of non-infringement and invalidity of Amgen’s U.S. Patent No. 9,643,997 (“the ʼ997 patent”). The ʼ997 patent is directed to methods of purifying a protein expressed in a non-native limited solubility form in a non-mammalian
