Compound Name:TocilizumabMolecular Target:IL-6 receptor (IL-6R)Molecular Structure:humanized, recombinantLicensed Indication:Rheumatoid Arthritis (Japan), systemic-onset Juvenile Idiopathic Arthritis (Japan)Manufacturer and/or Distributor:F.Hoffman-La Roche and Chugai PharmaceuticalsInitial FDA Approval:2010Summary:Tocilizumab is a recombinant humanized anti-human interleukin-6 (IL-6) receptor monoclonal antibody of the immunoglobulin IgG1k subclass. It binds both the membrane bound and soluble forms for the receptor, and thus blocks IL-6 mediated pro-inflammatory effects. Tocilizumab was FDA-approved in 2010 as an intravenous infusion for the treatment of adult patients with moderately to severely active rheumatoid arthritis (RA) with an inadequate response to one or more tumor necrosis factor (TNF) inhibitor therapies (e.g., infliximab). It has been shown to inhibit the progression of structural joint damage and to improve physical function. A subcutaneous formulation was later approved, with the same indication, in 2013. Tocilizumab is also approved for children with systemic (2011) or polyarticular (2013) juvenile idiopathic arthritis. Tocilizumab is the first IL-6 receptor-inhibiting monoclonal antibody approved to treat RA and may be used alone or in combination with methotrexate or other disease modifying anti-rheumatic drugs (DMARDs). Based on the formulation used, tocilizumab is typically administered every one to four weeks. Various reports on off-label use of tocilizumab strongly suggest its use for acute, severe complications such as systemic inflammatory response syndrome and cytokine-release syndrome. There are ongoing clinical trials ( assessing the efficacy of tocilizumab for the treatment of hemophagocytic lymphiohistiocytosis, treatment-refractory polymyositis and dermatomyositis, new-onset type I DM, Castleman disease, sjögren’s syndrome, uveitis, osteoarthritis, hepatocellular carcinoma, and other diseases. Major safety concerns are serious infections (including opportunistic infections), liver enzyme elevation, serum lipid abnormalities, cytopenias (neutropenia and thrombocytopenia), GI perforation, and hypersensitivity including anaphylaxis. Treated patients should not receive live vaccines. Tocilizumab is pregnancy category C.References

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