Structure of EP217609. The indirect factor Xa inhibitor moiety (fondaparinux analog), direct thrombin inhibitor moiety, and biotin label of EP217609 are indicated. The biotin is attached to the linker between the 2 inhibitor moieties through a lysine spacer indicated by the arrow. EP217609 is a mixture of diastereomers containing either an L-lysine spacer (EP217609-1) or a D-lysine spacer (EP307138-1). EP42675 lacks the lysyl-biotinyl group indicated by a box.