An anti-inflammatory treatment used to treat rheumatoid arthritis reduces the risk of death when given to hospitalised patients with severe Covid-19, according to a new study.

The Randomised Evaluation of COVID-19 Therapy (RECOVERY) study found that tocilizumab shortens the time until patients are successfully discharged from hospital and reduces the need for a mechanical ventilator.

The RECOVERY trial has been testing a range of potential treatments for Covid-19 since March 2020. Tocilizumab 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 2,022 patients were randomly allocated to receive tocilizumab by intravenous infusion and were compared with 2,094 patients randomly allocated to usual care alone. 82% of patients were taking a systemic steroid such as dexamethasone.

Treatment with tocilizumab significantly reduced deaths

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. 

The data suggest that in Covid-19 patients with hypoxia (requiring oxygen) and significant inflammation, treatment with the combination of a systemic corticosteroid (such as dexamethasone) plus tocilizumab reduces mortality by about one third for patients requiring simple oxygen and nearly one half for those requiring invasive mechanical ventilation.

Peter Horby, Professor of Emerging Infectious Diseases in the Nuffield Department of Medicine, University of Oxford, and 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."

The preliminary results will be made available via medRxiv shortly and submitted to a peer-reviewed medical journal. For this preliminary report, information on the primary outcome was available for 92% of patients.