Currently available interleukin 6 (IL-6) inhibitors

Tocilizumab (Actemra)Sarilumab (Kevzara)Siltuximab (Sylvant)
Mechanism of actionTocilizumab and sarilumab: Bind to soluble and membrane-bound IL-6 receptors and inhibit IL-6-mediated signalingBinds to IL-6 and prevents binding of IL-6 to soluble and membrane-bound IL-6 receptors
Approved indications and dosingRheumatoid arthritis: 4 mg/kg IV every 4 weeks (up to 8 mg/kg every 4 weeks); 162 mg SQ everyother week (up to every week)
Giant cell arteritis: 162 mg SQ once weekly or every other week
Polyarticular juvenile idiopathic arthritis: 8 mg/kg IV every 4 weeks (10 mg/kg if < 30 kg); 162 mg SQ every other week (every 3 weeks if < 30 kg)
Systemic juvenile idiopathic arthritis: 8 mg/kg IV every other week (12 mg/kg if < 30 kg); 162 mg SQ every week (every other week if < 30 kg)
Cytokine release syndrome (due to chimeric antigen receptor T-cell therapy): 8 mg/kg IV (10 mg/kg if < 30 kg)
Moderately to severely active rheumatoid arthritis: 200 mg SQ every other weekMulticentric Castleman disease: 11 mg/kg IV over 1 hour every 3 weeks until treatment failure
ContraindicationsTocilizumab, sarilumab, and siltuximab:
  • Safety data are insufficient to recommend use of these agents during pregnancy or breastfeeding

  • Use with caution in patients with serious active infection or increased risk of gastrointestinal perforation

Tocilizumab and sarilumab: avoid use in patients with
  • ANC < 2,000/mm3

  • Platelet count < 100,000/mm3

  • ALT/AST > 1.5 x ULN

  • Tuberculosis or latent tuberculosis infection

COVID-19 dosing4-8 mg/kg IV for one or two doses (doses given within 24 hours of each other)200 mg SQ once
400 mg IV once
11 mg/kg IV once
Maximum dose: 800 mg IV
Current COVID-19 clinical trialsNCT04317092, NCT04335071,
NCT04320615, NCT04306705,
NCT04310228, NCT04335305,
NCT04333914, NCT04339712,
NCT04330638, NCT04322773,
NCT04331795, NCT04332094,
NCT04332913, NCT04331808
NCT04341870, NCT04315298,
NCT04327388, NCT04324073,
NCT04321993, NCT04322773
NCT04329650, NCT04322188,
  • ALT = alanine aminotransferase; ANC = absolute neutrophil count; AST = aspartate aminotransferase; IV = intravenously; SQ = subcutaneously; ULN = upper limit of normal