COVID-19 research briefs: Evidence for effectiveness for tocilizumab for COVID-19 treatment inconclusive and not encouraging

Reference

Parr JB. Time to reassess tocilizumab's role in COVID-19 pneumonia. JAMA Intern Med. Published online October 20, 2020. doi:10.1001/jamainternmed.2020.6557.

Synopsis

Research Brief #68: We usually summarize single studies, but because of the inconclusive evidence for the efficacy of tocilizumab for the treatment of COVID-19 and the many clinical trials of tocilizumab recently published and still underway, we'll address an editorial that summarizes the evidence as of October 22, 2020. Tocilizumab is a monoclonal antibody against interleukin 6 (IL-6) receptors that is used to treat inflammatory arthritis and giant cell arteritis. Because of its anti-inflammatory effects, it was felt to be a good candidate to treat severe COVID-19 infection, in which much of the morbidity is due to severe inflammation. In this editorial, the author summarizes the results of 5 studies: 1 observational study, 2 completed randomized trials, and 2 incomplete randomized trials that have reported interim results. The observational study, STOP-COVID, found an improvement of 9.6% in estimated 30-day mortality, but was subject to unmeasured or residual confounding. The 2 small randomized trials published online in JAMA Internal Medicine on October 20, 2020, RCT-TCZ-COVID-19 and CORIMUNO-TOCI-1, found little benefit. Differences in mortality at 28 days and 30 days of 1.7% and 0.8%, respectively, were not statistically significant. Two larger randomized trials, COVACTA and EMPACTA, found nonsignificant differences in 28-day mortality of 0.3% and 1.8% favoring placebo, although these are preliminary results based on approximately 400 enrolled patients in each trial. There was a reduction in the need for mechanical ventilation in the EMPACTA trial. Another small randomized trial published in the New England Journal of Medicine in October (not included in this editorial) found that tocilizumab was not effective for preventing intubation or death in moderately ill hospitalized patients with COVID-19. The results from the 5 included trials are considered inconclusive because of small sample sizes, but taken together the results are not encouraging.