How to administer tocilizumab

Tocilizumab is a biologic agent used to treat rheumatoid arthritis (RA), giant cell arteritis (GCA), and systemic sclerosis-related interstitial lung disease (SSc-ILD) , Polyarticular Juvenile Idiopathic Arthritis (PJIA), Systemic Juvenile Idiopathic Arthritis (SJIA), Cytokine Release Syndrome (CRS), and COVID-19 (COVID-19) patients need to undergo clinical evaluation by a doctor and use it in accordance with the doctor's instructions.

1. Recommended dose: Tocilizumab can be used as monotherapy or in combination with methotrexate or other non-biological drugs, as an intravenous infusion or subcutaneous injection. Because body weight may fluctuate, do not change the dose based solely on weight measurements at a single visit.

(1) Rheumatoid Arthritis (RA): As an intravenous infusion, the recommended dose of tocilizumab in adult patients is 4 mg/kg every 4 weeks, then increased to 8 mg/kg every 4 weeks based on clinical response. Doses exceeding 800 mg per infusion are not recommended in patients with RA. Patients weighing less than 100 kg are recommended to receive 162 mg subcutaneously every other week and then increasing to weekly based on clinical response. Patients weighing 100 kg or more are recommended to receive 162 mg subcutaneously every week. When transitioning from intravenous tocilizumab therapy to subcutaneous dosing, the first subcutaneous dose should be given instead of the next scheduled intravenous dose.

(2) Giant cell arteritis (GCA): The recommended dose of tocilizumab for adult patients is 6 mg/kg every 4 weeks as a single 60-minute intravenous infusion combined with a tapering course of glucocorticoids. The recommended dose of tocilizumab for adults with GCA is 162 mg subcutaneously administered once weekly in combination with tapering courses of corticosteroids. Based on clinical considerations, a dose of 162 mg subcutaneously every other week may be prescribed and this drug may be used alone after discontinuation of glucocorticoids.

(3) Systemic sclerosis-associated interstitial lung disease (SSc-ILD): The recommended dose of tocilizumab is 162 mg subcutaneously injected once weekly.

(4) Polyarticular juvenile idiopathic arthritis (PJIA): For PJIA patients, the recommended dose of tocilizumab for patients weighing less than 30kg is 10mg/kg, and for patients weighing greater than 30kg, the recommended dose of tocilizumab is 5mg/kg, once every 4 weeks, as a 60-minute intravenous infusion. The recommended subcutaneous dose of tocilizumab is 162 mg every three weeks for patients weighing less than 30 kg and 162 mg every two weeks for patients weighing greater than 30 kg.

（5) Systemic juvenile idiopathic arthritis (SJIA): The recommended dose of tocilizumab for patients weighing less than 30kg is 12mg/kg, and for patients weighing more than 30kg, the recommended dose of tocilizumab is 8mg/kg, once every 2 weeks, intravenous infusion for 60 minutes each time. The recommended subcutaneous dose of tocilizumab is 162 mg once every two weeks for patients weighing less than 30 kg and 162 mg once weekly for patients weighing greater than 30 kg.

（6) Cytokine release syndrome (CRS): only use intravenous route for treatment. The recommended dose of tocilizumab for patients weighing less than 30kg is 12mg/kg. For patients weighing more than 30kg, the recommended dose of tocilizumab is 8mg/kg, intravenous infusion every 60 minutes. It may be used alone or in combination with corticosteroids. If signs and symptoms of CRS do not improve clinically after the first dose, tocilizumab may be administered up to 3 additional times, with an interval of at least 8 hours between consecutive doses. Doses exceeding 800 mg per infusion are not recommended for patients with CRS.

（7) New coronavirus pneumonia (COVID-19): The recommended dose of tocilizumab for the treatment of adult patients with new coronavirus pneumonia is 8 mg/kg as a single 60-minute intravenous infusion. If clinical signs or symptoms worsen or do not improve after the first dose, another infusion of tocilizumab can be given at least 8 hours after the first infusion. It is not recommended that patients with COVID-19 should infuse more than 800 mg per infusion.

2. Dose adjustment: If the patient develops severe infection, tocilizumab treatment should be suspended until the infection is controlled. Interruption of dosing may be necessary if associated laboratory abnormalities occur, including elevated liver enzymes, neutropenia, and thrombocytopenia. For example, For patients with RA, GCA, or SSc-ILD whose ALT or AST elevation exceeds 1.5 times the ULN, it is not recommended to start tocilizumab treatment. For patients with ALT or AST elevation that exceeds 5 times the ULN, tocilizumab should be discontinued.