To provide a novel JAK3 inhibitor that is useful as a preventive and/or therapeutic agent for rejection and graft versus host disease (GvHD) in organ transplantation, rheumatoid arthritis, multiple sclerosis, systemic lupus erythematosus, Sjögren syndrome, Behcet's disease, type I diabetes mellitus, autoimmune thyroiditis, idiopathic thrombocytopenic purpura, ulcerative colitis, Crohn's disease, asthma, allergic rhinitis, atopic dermatitis, contact dermatitis, urticaria, eczema, psoriasis, allergic conjunctivitis, uveitis, cancer, leukemia and the like. The pyridine-3-carboxyamide derivative represented by the general formula (1): or its salt or a solvate thereof.