The purpose of the present invention is to provide a novel therapeutic agent which is useful for the treatment of primary biliary cirrhosis (PBC). The present invention relates to a pharmaceutical composition for treating PBC, which contains a therapeutically effective amount of (R)-2-[3-[[N-(benzoxazol-2-yl)-N-3-(4-methoxyphenoxy)propyl]aminomethyl]phenoxy]butyric acid, a salt of the compound, or a solvate of the compound or the salt.