Orange Book Blog

Barr Labs announced that yesterday, Eli Lilly filed a patent infringement lawsuit against Barr relating to Lilly’s Prozac Weekly drug product.  Lilly filed suit in the Southern District of Indiana, alleging infringement of U.S. reissue patent RE39,030.  According to Barr’s press release, Barr filed its ANDA seeking approval of a generic version of Prozac Weekly in September, 2001, and filed a paragraph iv certification to the Orange Book listed patents at that time.  Lilly, however, chose not to file suit against Barr until its reissue patent was granted.

Previously, Barr successfully challenged other Lilly patents covering its daily Prozac drug product.  The 2001 en banc Federal Circuit decision invalided Lilly’s patents on double-patenting grounds.  Lilly appealed to the Supreme Court, but cert was denied.