Methods using HDAC11 inhibitors

A method of treating cancer in a patient in need thereof, comprising administering to a patient an effective amount of a HDAC11 inhibitor, wherein the HDAC11 inhibitor is a compound of Formula I-A or a pharmaceutically acceptable salt thereof,

• wherein:
• X1, X2, X3, and X4 are each CR1;
• R1 is independently, at each occurrence, —H;
• R6 is —H, —C1-C6alkyl, —C2-C6alkenyl, —C4-C8cycloalkenyl, —C2-C6alkynyl, —C3-C8cycloalkyl, heterocyclyl, aryl, heteroaryl containing 1-5 heteroatoms selected from the group consisting of N, S, P and O, —S(O)2N(C1-C6alkyl)2, —S(O)2(C1-C6alkyl), —(C1-C6alkyl)S(O)2R5, —C(O)C1-C6alkyl, —C(O)OC1-C6alkyl, or —(CHR5)pNR3R4 wherein each alkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, and heteroaryl is optionally substituted with one or more substituents selected from —OH, halogen, —NO2, oxo, —CN, —R5, —O(C1-C6)alkyl, —NH(C1-C6)alkyl, —N(C1-C6alkyl)2, —S(O)2N(C1-C6alkyl)2, —S(O)2NHC1-C6alkyl, —C(O)C1-C6alkyl, —C(O)OC1-C6alkyl, —N(C1-C6alkyl)S(O)2C1-C6alkyl, —S(O)R5, —S(O)N(C1-C6alkyl)2, —N(C1-C6alkyl)S(O)R5, heterocycle, aryl, or heteroaryl;
• R3 and R4 are independently, at each occurrence, —H, —C1-C6alkyl, —C2-C6alkenyl, —C4-C8cycloalkenyl, —C2-C6alkynyl, —C3-C8cycloalkyl heterocyclyl, aryl, heteroaryl containing 1-5 heteroatoms selected from N, S, P, and O, —S(O)2N(C1-C6alkyl)2, —S(O)2(C1-C6alkyl),—(C1-C6alkyl)S(O)2R5, —C(O)C1-C6alkyl, —C(O)OC1-C6alkyl, oxo, or —(CHR5)pN(C1-C6alkyl)2, wherein each alkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, and heteroaryl is optionally substituted with one or more substituents selected from —OH, halogen, —NO2, oxo, —CN, —R5, —O(C1-C6)alkyl, —NH(C1-C6)alkyl, —N(C1-C6alkly)2, —S(O)2N(C1-C6alkyl)2, —S(O)2NHC1-C6alkyl, —C(O)C1-C6alkyl, —C(O)OC1-C6alkyl, —N(C1-C6alkyl)S(O)2C1-C6alkyl, —S(O)R5, —S(0)N(C1-C6alkyl)2, —N(C1-C6alkyl)S(OR5, heterocycle, aryl, or heteroaryl:
• R5 is independently, at each occurrence, —H, —C1-C6alkyl, —C2-C6alkenyl, —C4-C8cycloalkenyl, —C2-C6alkynyl, —C3-C8cycloalkyl, heterocyclyl, aryl, heteroaryl containing 1-5 heteroatoms selected from N, S, P and O, —OH, halogen, —NO2, —CN, —NHC1-C6alkyl, —N(C1-C6alkyl)2, —S(O)2NH(C1-C6alkyl), —S(O)2N(C1-C6alkyl)2, —S(O)2C1-C6alkyl, —C(O)C1-C6alkyl, —C(O)OC1-C6alkyl, —N(C1-C6alkyl)SO2C1-C6alkyl, —S(O)(C1-C6alkyl), —S(O)N(C1-C6alkyl)2, —N(C1-C6alkyl)S(O)(C1-C6alkyl) or —(CH2)pN(C1-C6alkyl)2;
• and
• p is 0, 1, 2, 3, 4, 5, or 6.