Tricyclic heterocycles as bet protein inhibitors

1. A compound which is (4S)-2-[4-(cyclopropylcarbonyl)piperazin-1-yl]-7-(3,5-dimethylisoxazol-4-yl)-4-pyridin-2-yl-4,5-dihydroimidazo[1,5,4-de][1,4]benzoxazine, or a pharmaceutically acceptable salt thereof.

2. A pharmaceutical composition comprising the compound of claim 1 , or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier.

3. A method of treating cancer comprising administering to a patient in need of such treatment a therapeutically effective amount of the compound of claim 1 , or a pharmaceutically acceptable salt thereof, wherein the cancer is adenocarcinoma, bladder cancer, blastoma, bone cancer, breast cancer, brain cancer, carcinoma, myeloid sarcoma, cervical cancer, colorectal cancer, esophageal cancer, gastrointestinal cancer, glioblastoma multiforme, glioma, gallbladder cancer, gastric cancer, head and neck cancer, Hodgkin's lymphoma, non-Hodgkin's lymphoma, intestinal cancer, kidney cancer, laryngeal cancer, leukemia, lung cancer, lymphoma, liver cancer, small cell lung cancer, non-small cell lung cancer, mesothelioma, multiple myeloma, ocular cancer, optic nerve tumor, oral cancer, ovarian cancer, pituitary tumor, primary central nervous system lymphoma, prostate cancer, pancreatic cancer, pharyngeal cancer, renal cell carcinoma, rectal cancer, sarcoma, skin cancer, spinal tumor, small intestine cancer, stomach cancer, T-cell leukemia, T-cell lymphoma, testicular cancer, thyroid cancer, throat cancer, urogenital cancer, urothelial carcinoma, uterine cancer, vaginal cancer, or Wilms' tumor.

4. A method of treating an autoimmune or inflammatory disease comprising administering to a patient in need of such treatment a therapeutically effective amount of a compound of claim 1 , or a pharmaceutically acceptable salt thereof, wherein the autoimmune or inflammatory disease is selected from allergy, allergic rhinitis, arthritis, asthma, chronic obstructive pulmonary disease, degenerative joint disease, dermatitis, organ rejection, eczema, hepatitis, inflammatory bowel disease, multiple sclerosis, myasthenia gravis, psoriasis, sepsis, sepsis syndrome, septic shock, systemic lupus erythematosus, tissue graft rejection, and type I diabetes.

5. A method of treating a viral infection comprising administering to a patient in need of such treatment a therapeutically effective amount of the compound of claim 1 , or a pharmaceutically acceptable salt thereof.

6. The method of claim 5 , wherein the viral infection is infection with adenovirus, Epstein-Barr virus, hepatitis B virus, hepatitis C virus, a herpes virus, human immunodeficiency virus, human papilloma virus or a pox virus.