Tocilizumab Calms Cytokine Storm and Lowers Risk of Dying by 45% in COVID-19 Patients on Ventilators

A study has found that critically ill COVID-19 patients who received tocilizumab, a drug that calms an overreacting immune system, were 45% less likely to die and more likely to leave the hospital or get off a ventilator one month after treatment, compared with those who did not receive the drug.

The study by the University of Michigan (Ann Arbor, MI, USA) found that the risk of death in patients who received a single dose of intravenous tocilizumab was lower despite the fact that they also had twice the risk of developing an additional infection, on top of the novel coronavirus. The findings suggest a benefit from timely and targeted efforts to calm the “cytokine storm” caused by the immune system’s overreaction to the coronavirus. Tocilizumab, originally designed for rheumatoid arthritis, has already been used to calm such storms in patients receiving advanced immunotherapy treatment for cancer.


The researchers have based their conclusions on a thorough look back at data from 154 critically ill patients. The team found that by the end of the 28-day period after patients went on a ventilator, 18% of those who received tocilizumab had died, compared with 36% of those who had not. When adjusted for health characteristics, this represents a 45% reduction in mortality. Of those still in the hospital at the end of the study period, 82% of the tocilizumab patients had come off the ventilator, compared with 53% of those who did not receive the drug. In all, 54% of the tocilizumab patients had developed a secondary infection, mostly ventilator associated pneumonia; 26% of those who didn’t receive tocilizumab developed such infections. Such “superinfections” usually reduce the chance of survival for COVID-19 patients.

“One role of epidemiology is to rigorously evaluate real-world data on treatment effects, especially when evidence from clinical trials is not available. We kept trying to prove ourselves wrong as signals of benefit emerged in the data, both because of the immediate implications of these data, and in part because of concern about the supply of the medication for other patients,” said lead author Emily Somers, Ph.D., Sc.M., an epidemiologist who has studied both rheumatologic and immunologic diseases. “But the difference in mortality despite the increase in secondary infection is quite pronounced, even after accounting for many other factors.”

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