The present inventors successfully provided constant regions capable of enhancing the agonist activity of antibodies through amino acid sequence alterations. Specifically, agonist activity was found to be enhanced in antibodies having a constant region in which amino acids of the antibody heavy chain constant region are substituted or deleted, or antibodies having a constant region in which the hinge region amino acids are substituted. Use of such antibodies as pharmaceutical formulations can provide pharmaceutical formulations with improved performance.
