The present invention is directed to a pharmaceutically acceptable crystalline addition salt of (i) 5-[(1R)-2-({2-[4-(2,2-difluoro-2-phenylethoxy)phenyl]ethyl}amino)-1-hydroxyethyl]-8-hydroxyquinolin-2(1H)-one, and (ii) a dicarboxylic acid, a sulfonic acid or a sulfimide, or a pharmaceutically acceptable solvate thereof.