Patent 7091186 was granted and assigned to Seagen on August, 2006 by the United States Patent and Trademark Office.
Compounds of the formulaeLAn-Z-X—WwD and BZ-X—WwDwherein: D is a drug moiety; L is a ligand; B is a blocking group; A is an optional acyl unit; Z is an amino acid or a peptide residue; X is an aminobenzyl ether self-immolative spacer group; W is an optional second self-immolative group; n is an integer of 0 or 1; and w is an integer of 0 or 1, and compositions of said compounds with pharmaceutically acceptable carrier, diluent and/or excipient, and methods of delivery the drug D via the compounds.