Tocilizumab

Tocilizumab, as a humanised monoclonal antibody, can target both membrane-bound and soluble forms of the IL-6 receptor.^[1] Tocilizumab has been approved for treatment in patients with rheumatologic disorders and chimeric antigen receptor T cell-induced cytokine release syndrome.^[3]

In vitro efficacy test it shown that treatment with tocilizumab (1 or 10 μm) or SOMAmer (0.83 or 8.3 μm), SOMAmer suppressed the proliferation of U87MG and HepG2 cells to a greater extent than tocilizumab at similar molar concentrations.^[7]

In vivo efficacy test it indicated that treatment with 8 mg/kg tocilizumab using two consecutive intravenous infusions 12 h apart in 100 patients with COVID-19 and ARDS requiring ventilatory support in Brescia (Italy) has 20% mortality according to an optional third infusion based on clinical response.^[1] In vivo, tocilizumab 8 mg/kg × 1 in mechanically ventilated patients, the results shown that receipt of tocilizumab was independently associated with improved survival.^[2] In vivo study for the treatment of rheumatoid arthritis, treatment with 4 mg/kg tocilizumab, the results exhibited that the average IL-6 level reached the peak at the second week after administration, and then decreased gradually.^[4] In a 61-year-old man with COVID-19, treatment with 324 mg Tocilizumab via subcutaneous with hydroxychloroquine can successfully manage the infection.^[6] In addition, the recommended dose of Tocilizumab is 4–8 mg/kg administered as a single 60- minute intravenous infusion every 4 weeks for treatment in moderate to severe active arthritis in adults, Giant cell arthritis, Polyarticular juvenile idiopathic arthritis and cytokine release syndrome in patients 2 years of age older with active disease.^[5]

References:
[1] Lan SH, et al. Tocilizumab for severe COVID-19: a systematic review and meta-analysis. Int J Antimicrob Agents. 2020 Sep;56(3):106103.
[2]Somers EC, et al. Tocilizumab for Treatment of Mechanically Ventilated Patients With COVID-19. Clin Infect Dis. 2021 Jul 15;73(2):e445-e454.
[3]Wei Q, et al. Tocilizumab treatment for COVID-19 patients: a systematic review and meta-analysis. Infect Dis Poverty. 2021 May 18;10(1):71.
[4]Smolen J.S, et al. Effect of interleukin-6 receptor inhibition with tocilizumab in patients with rheumatoid arthritis (OPTION study): a double-blind, placebo-controlled, randomised trial. Lancet. 2008;371(9617):987–997.
[5]Sebba A, et al. Tocilizumab: the first interleukin -6 receptor inhibitor. Am J Health Syst Pharm. 2008;65(15):1413–1418.  
[6]Fontana F, et al. Covid-19 pneumonia in a kidney transplant recipient successfully treated with Tocilizumab and Hydroxychloroquine. Am. J. Transplant. American J. Transplant. 2020;20(7).
[7]Gupta S, et al. Chemically modified DNA aptamers bind interleukin-6 with high affinity and inhibit signaling by blocking its interaction with interleukin-6 receptor. J Biol Chem. 2014 Mar 21;289(12):8706-19.