A method of treating cancer comprising administering to a subject in need thereof an effective amount of a compound which is 17-chloro-5,13,14,22-tetramethyl-28-oxa-2,9-dithia-5,6,12,13,22-pentaazaheptacyclo[27.7.1.14,7.011,15.016,21.020,24.030,35]octatriaconta-1(37),4(38),6,11,14,16,18,20,23,29,31,33,35-tridecaene-23-carboxylic acid (Formula I)
- or a pharmaceutically acceptable salt thereof;
- wherein the cancer is a hematological malignancy selected from acute myeloid leukemia, multiple myeloma, mantle cell lymphoma, chronic lymphocytic leukemia, diffuse large B cell lymphoma, Burkitt's lymphoma, and follicular lymphoma.