By Jonathan Fitzgerald, Simone Raess, Jeffrey Morton and William Mulholland (January 30, 2019, 1:09 PM EST) -- In October of 2017, in Amgen v. Sanofi,[1] the Federal Circuit overturned the "newly characterized antigen" test. This test — which was adopted by the Federal Circuit in 2002, in the Enzo Biochem v. Gene Probe[2] case — permitted patentees to claim a genus of antibodies by describing the structure of a corresponding antigen, rather than by describing the structure of the claimed antibodies themselves. The U.S. Patent and Trademark Office had issued broad claims to antibodies under the newly characterized antigen test for more than 15 years. This practice was a boon to biotechnology companies, who were able to obtain broad patent protection over a genus of antibodies early in the development and testing process....