Tocilizumab, an immunosuppressant originally developed as a rheumatoid arthritis treatment, has demonstrated further benefits in treating patients critically ill with COVID-19. In the study by researchers at the University of Michigan, Ann Arbor, Michigan, USA, patients who received tocilizumab were 45% less likely to die and more likely to be well enough to be withdrawn from ventilation within 28 days, compared to those who did not receive the drug.
The retrospective, single-centre study included 154 critically ill patients with a confirmed COVID-19 diagnosis. One-half of the patients received intravenous tocilizumab, with many receiving this within 24 hours intubation. The patients were monitored for 28 days following their intubation and, by the end of this period, 18% of patients who received tocilizumab had died, compared to 36% of patients who had not received the drug, representing a 45% reduction in mortality (adjusted for health characteristics). Furthermore, 82% of patients treated with tocilizumab who were still in the hospital were able to be withdrawn from ventilation, compared to 53% who did not receive the drug.
The risk of developing a secondary infection was increased in the patients who received tocilizumab compared to those who did not receive the medication (54% versus 26%, respectively). The secondary infections were mostly ventilator-associated pneumonia, which usually reduce survival rates in COVID-19 patients.
Dexamethasone has been shown to be beneficial in critically ill COVID-19 patients in a study with more robust data, and it is 100 times less expensive than a single dose of tocilizumab. Prof Jason Pogue from the University of Michigan commented that: “But at this time, due to the lack of randomised, controlled trial data and the much higher cost, we recommend reserving tocilizumab for the treatment of select patients who decompensate while on or after receiving dexamethasone or in patients where the risks of adverse events from steroid therapy outweigh the potential benefits.”
These data, in addition to previously described preliminary benefits in dampening SARS-CoV-2-infection associated cytokine storm, highlight that tocilizumab may be beneficial to patients critically ill with COVID-19. However, because of the cost and risk of secondary infection, the use of tocilizumab may be best reserved for those most critically ill.