USE OF TRICYCLIC HETEROARYL-CONTAINING COMPOUND

The present application provides the use of a compound (I) or an optical isomer or pharmaceutically acceptable salt thereof in preparation of a medicament for treating JAK and SYK kinase high expression or abnormal activation related diseases, including autoimmune diseases such as immune-mediated skin diseases, particularly psoriasis, atopic dermatitis, and SLE. The compound (I) or the optical isomer or pharmaceutically acceptable salt thereof in the present invention can mitigate skin lesions of mice suffering from psoriasis, atopic dermatitis, and SLE, relieves renal injury, inhibits enlargement of immune organs, reduces the level of inflammation, inhibits increase of SLE-related antibodies and cytokines in serum, has a certain safe therapeutic window, and has good prospects of clinical application.