As per the notification on 24 June 2021, the United States Food and Drug Administration (US-FDA) granted an emergency use authorization (EUA) to tocilizumab to treat hospitalized COVID-19 adults and pediatrics (age: two years and older) who are being treated with systemic corticosteroids and need, mechanical ventilation (invasive/non-invasive), supplemental oxygen, or extracorporeal membrane oxygenation (ECMO). This drug is not authorized for usage in outpatients suffering from coronavirus infection.

In trials of people hospitalized due to SARS-CoV-2, treatment with tocilizumab plus routine care (including corticosteroid therapy) was found to minimize mortality risk through 28 days of follow-up and shorten the amount of time people remained hospitalized. Also, the risk from being on a ventilator or mortality through 28 days of follow-up was reduced.

Tocilizumab, an FDA-approved agent for numerous inflammatory diseases (including rheumatoid arthritis) is administered by intravenous infusion. By blocking the interleukin-6 receptor, tocilizumab alleviates inflammation. It is well-known that coronavirus-infected people may develop a hyperactive immune system that may further deteriorate the disease. This monoclonal antibody does not directly target the deadly virus.

The data supporting tocilizumab's EUA are based on three randomized, placebo-controlled, double-blind trials (REMDACTA, EMPACTA, and COVACTA) and one randomized, open-label, controlled, platform trial [Randomised Evaluation of COVID-19 Therapy (RECOVERY)]. While all the four studies contribute to the FDA’s insight of tocilizumab for treating COVID-19, the most crucial scientific evidence on the promising advantages of tocilizumab for its authorized usage came from the EMPACTA and RECOVERY studies.

In the EMPACTA trial, 389 hospitalized subjects having coronavirus pneumonia were randomly allocated to receive tocilizumab (n=249) or a placebo (n=128). For tocilizumab recipients, a decline was noted in advancement to mechanical ventilation or death compared to placebo recipients, with the primary assessment findings being statistically significant. The percentage of individuals who needed mechanical ventilation or died by day 28 was less for the tocilizumab-treated group vs. placebo group (12% vs. 19.3%).

In the REMDACTA trial, 649 hospitalized people suffering from severe coronavirus pneumonia were randomly divided to receive a combination of tocilizumab and remdesivir (n=430) or a combination of placebo and remdesivir (n=210). Regarding the time to hospital discharge or ready for discharge through 28 days of the follow-up, no vital inter-group differences were reported. However, this study contributed to the determination of tocilizumab's safety when used for combating coronavirus infection.

In the RECOVERY study, 4,116 hospitalized people having serious coronavirus pneumonia were randomly assigned to either tocilizumab in addition to the usual care group (n=2,022) or the usual care alone group (n=2,094). The outcomes of the primary assessment were statistically significant. Compared with the group receiving only usual care, the tocilizumab + usual care group illustrated a shorter median time to hospital discharge (28 days vs. 19 days) and reduced probabilities of death by day 28 (34.9% vs. 30.7%).

In the COVACTA trial, 452 hospitalized individuals having severe coronavirus pneumonia were randomly segregated to receive tocilizumab (n=294) or a placebo (n=144). While no profound differences were witnessed in the clinical status on the 7-category ordinal scale at day 28 between the therapeutic groups, this trial contributed to evaluation of tocilizumab's safety when used for treating coronavirus infection.

Nausea, constipation, insomnia, anxiety, hypertension, and diarrhea are the commonly noted adverse effects of tocilizumab noted in the coronavirus trials.