Table 6.

A comparison of the two IL-6 blocking monoclonal antibodies approved for clinical use.

Characteristics	Tocilicumab	Siltuximab
Specificity	Anti IL-6R (membrane and soluble)	Anti IL-6
Antibody structure	Humanized	Chimeric (mouse/human)
Administration	Subcutaneous or intravenous	Intravenous
Approved indications	Rheumatoid arthritis	HIV-negative muticentric Castleman’s disease
	Systemic juvenile idiopathic arthritis
Example of reported off-label use	Cytokine release syndrome after CAR-T therapy
	Giant cell arteritis
	Graft-versus-host disease
	Adult Still’s disease