Equivalence In Chemical Cases

In Mylan Institutional LLC et al. v. Aurobindo Pharma Ltd. et al., 2017-1645 (May 19, 2017), the Federal Circuit attempted to clarify the application of the doctrine of equivalents in chemical cases. Although affirming a district court grant of a preliminary injunction on a patent directed to isosulfan blue (ISB), a dye used for lymph node mapping, the court reversed the grant of the injunction to the extent it was based on two process patents. According to the Federal Circuit, the district court erred in determining that Mylan had demonstrated a likelihood of success in showing that Aurobindo infringes U.S. Patent 7,622,992 (the '992 patent) and U.S. Patent 8,969,616 (the '616 patent) because "the district court's analysis of equivalence in this case was flawed." Slip opinion at 12.