The RECOVERY trial has been testing a range of potential treatments for COVID-19 since March 2020. Tocilizumab, an intravenous drug used to treat rheumatoid arthritis, was added to the trial in April 2020 for patients with COVID-19 who required oxygen and had evidence of inflammation. Recruitment to the tocilizumab arm stopped on 24 January 2021 since, in the view of the trial Steering Committee, sufficient patients had been enrolled to establish whether or not the drug had a meaningful benefit.
A total of 2022 patients were randomly allocated to receive tocilizumab by intravenous infusion and were compared with 2094 patients randomly allocated to usual care alone. 82% of patients were taking a systemic steroid such as dexamethasone.
Treatment with tocilizumab significantly reduced deaths: 596 (29%) of the patients in the tocilizumab group died within 28 days compared with 694 (33%) patients in the usual care group (rate ratio 0·86; [95% confidence interval [CI] 0·77 to 0·96]; p=0·007), an absolute difference of 4%. This means that for every 25 patients treated with tocilizumab, one additional life would be saved. Tocilizumab also increased the probability of discharge alive within 28 days from 47% to 54% (rate ratio 1·23, [95% CI 1·12 to 1·34], p<0·0001). These benefits were seen in all patient subgroups, including those requiring oxygen via a simple face mask through to those requiring mechanical ventilators in an intensive care unit.
Among patients not on invasive mechanical ventilation when entered into the trial, tocilizumab significantly reduced the chance of progressing to invasive mechanical ventilation or death from 38% to 33% (risk ratio 0·85, [95% CI 0·78 to 0·93], p=0·0005). However, there was no evidence that tocilizumab had any effect on the chance of successful cessation of invasive mechanical ventilation.
Peter Horby, Joint Chief Investigator for RECOVERY, said ‘Previous trials of tocilizumab had shown mixed results, and it was unclear which patients might benefit from the treatment. We now know that the benefits of tocilizumab extend to all COVID patients with low oxygen levels and significant inflammation. The double impact of dexamethasone plus tocilizumab is impressive and very welcome.’