The drug tocilizumab, which is used in the treatment of various forms of arthritis, can greatly shorten the time on ventilation and shorten hospital stays for patients with severe COVID-19, a new study from Karolinska Institutet and Karolinska University Hospital published in The Journal of Internal Medicine reports.
“The report is, as far as we know, the first from Sweden to present results of a specific drug intervention for severe cases of COVID-19,” says principal investigator Piotr Nowak, researcher at Karolinska Institutet and infectious diseases consultant at Karolinska University Hospital (Huddinge).
The retrospective study began in March 2020 during an early phase of the COVID-19 pandemic and included 87 patients with severe COVID-19 in intensive care at Karolinska University Hospital in Huddinge, south of Stockholm. 29 of the patients received tocilizumab, a drug approved for the treatment of rheumatoid arthritis that blocks the so-called IL-6 receptor to prevent viral hyperinflammation (cytokine storm). Hyperinflammation triggered by the new coronavirus is central to the pathological process and causes high levels of the cytokine IL-6, which are associated with a more severe COVID-19 disease.
The differences between the treatment and control groups were significant. Patients who received tocilizumab were hospitalised for a much shorter length of time, including time spent on a ventilator, than those who received the standard treatment. The time spent on ventilation wasreduced by ten days, the time spent in intensive care by eight days, and the total hospital stay by ten days. The treatment was not associated with serious adverse events.
“So it seems we can help severely ill COVID-19 patients by affecting inflammation in the body with this treatment,” says Dr Nowak. “The results now need to be corroborated by a larger study that randomly assigns patients to either tocilizumab or other treatment.”
The researchers received no specific funding for the study and report no conflicts of interest.
The study reported above is a so-called retrospective cohort study, which involves working back from particular outcomes to determine possible causal factors. In this case, such a factor was who had received drug treatment and who had not. Retrospective studies are usually easier to conduct and less resource-demanding than prospective (forward-looking) studies. The drawback is that the results are less reliable since it is harder to control for different influencing factors. The most reliable results can be obtained from randomised controlled trials in which the participants are randomly assigned to either an experimental or a control group.