Schering Corp. v. Geneva Pharmaceuticals, Inc.

Schering Corp. (Schering) (plaintiff) held an earlier patent on loratadine (the active ingredient in Claritin) and a later patent on DCL, a metabolite the body naturally produces when loratadine is digested, even though the earlier patent never expressly mentioned DCL or metabolites at all. After the earlier patent expired, Geneva Pharmaceuticals (Geneva) (defendant) began making generic loratadine, and when Schering sued for infringing the later DCL patent, the district court found the earlier patent inherently anticipated the DCL claims under Section 102(b) and granted Geneva summary judgment of invalidity; Schering appealed, arguing DCL's existence was unknown and effectively secret before the critical date.