Abstract
BACKGROUND: With the arrival of the SARS-CoV-2 pandemic in 2020, it was proposed to make the change from intravenous (IV) tocilizumab (TCZ) to its subcutaneous formulation, in order to avoid rheumatological patients having to go to the day hospital and guarantee enough IV TCZ for those critical patients with COVID who needed it. The aim of this study was to describe the rate and reasons for switching back to IV TCZ from subcutaneous TCZ. METHODS: We included patients from the rheumatology service that were on treatment with IV TCZ in February 2020 and were followed up until March 2021. Patients that remained on subcutaneous TCZ were compared with those who switched back to IV TCZ (switch-back group). A subgroup analysis according to rheumatic disease was performed. RESULTS: Fifty-five patients switched to subcutaneous TCZ: 28 rheumatoid arthritis, 19 giant cell arteritis, 4 polymyalgia rheumatica, 2 juvenile idiopathic arthritis, and 2 systemic sclerosis. Seventeen patients switched back to IV TCZ due to ineffectiveness (n = 8), patient preference (n = 4), adverse events (n = 4), and difficulty with the SC administration route (n = 1). In the analysis by disease, 4 of 23 patients switched back to IV TCZ in giant cell arteritis/polymyalgia rheumatica group due to ineffectiveness (n = 2), injection site reaction (n = 1), or patient preference (n = 1). In rheumatoid arthritis group, 11 of 28 patients switched back to IV TCZ: ineffectiveness (n = 5), patient preference (n = 3), headache (n = 1), injection site reaction (n = 1), and due to difficulty with the SC administration route (n = 1). CONCLUSIONS: Mass switch from IV to subcutaneous TCZ during the SARS-CoV-2 pandemic has been safe, effective, and well tolerated after 1 year of follow-up.