Tocilizumab for giant cell arteritis (GCA)

Tocilizumab is a recombinant humanised anti-human monoclonal antibody directed against soluble and membrane‐bound interleukin‐6 receptors (IL‐6R) of the immunoglobulin IgG1 subclass (1):

• IL‐6, a pleiotropic cytokine produced by cells of various types, has diverse biological functions
  • is involved in T‐cell activation, stimulation of hematopoiesis, and in particular, induction of acute phase proteins; these acute phase proteins (e.g. ESR, CRP) are markedly high in individuals with GCA and are monitored clinically for disease activity
  • IL‐6 is locally produced in granulomatous lesions in the vasculitic arteries, as well as by circulating monocytes in GCA patients
• people with giant cell arteritis who have an injection of tocilizumab every week or two weeks have an improved chance of being symptom‐free after a year
• the systematic review states that "people treated with tocilizumab every four weeks probably have an improved chance of being symptom‐free after a year"

Study evidence that tocilizumab was confirmed to have an important steroid-sparing effect and a good safety profile in GCA patients (2).

Reference:

1. Antonio AA, Santos RN, Abariga SA. Tocilizumab for giant cell arteritis. Cochrane Database Syst Rev. 2022 May 13;5(5):CD013484.
2. Regola F, Cerudelli E, Bosio G, Andreoli L, Tincani A, Franceschini F, Toniati P. Long-term treatment with tocilizumab in giant cell arteritis: efficacy and safety in a monocentric cohort of patients. Rheumatol Adv Pract. 2020 May 15;4(2):rkaa017.