The present invention is directed to aziridinyl epothilone compounds as further described herein, and/or pharmaceutically-acceptable salts and/or solvates thereof having Formula (X), wherein K is -O-, -S-, or -NR7-； A is -(CRR)-(CH)m-Z- wherein Z is - (CHR)-, -C(=O)-, -C(=O)-C(=O)-, -OC(=O>；, -N(R)O=O)-, -SO-, or - N(R)SO-； B is hydroxyl or cyano and R is hydrogen or B and R are taken together to form a double bond； R, R, and R are, independently, hydrogen, alkyl, substituted alkyl, aryl or substituted aryl； or R and R may be taken together with the carbon to which they are attached to form an optionally substituted cycloalkyl； R is hydrogen, alkyl, alkenyl, substituted alkyl, substituted alkenyl, aryl, or substituted aryl； R is hydrogen, alkyl or substituted alkyl； R, R, R, R, R and R are independently hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, aryl, substituted aryl, heterocycloalkyl, substituted heterocycloalkyl, heteroaryl, or substituted heteroaryl； and R is aryl, substituted aryl, heteroaryl or substituted heteroaryl.
