In a major breakthrough, researchers including one of Indian-origin have found that tocilizumab drug reduced mortality by 30 per cent among critically ill Covid-19 patients when administered within the first two days of ICU admission.
For the study, published in the journal JAMA Internal Medicine, the research team investigated the effects of the anti-inflammatory drug tocilizumab on critically ill patients with laboratory-confirmed Covid-19.
"Unlike steroids, which suppress the immune system more broadly, tocilizumab specifically inhibits the receptor for the pro-inflammatory cytokine, IL-6," said the study authors from Brigham and Women's Hospital in the US.
For the current study, the research team used a 'target trial emulation' approach to examine whether tocilizumab reduces mortality in Covid-19.
Target trial emulation, a novel method of analysing observational data, is the idea of simulating a randomised control trial to reduce bias.
Of the 3,924 patients included in the analysis, 433 received tocilizumab in the first two days of ICU admission.
The risk of death at 30-days was 27.5 and 37.1 per cent among tocilizumab-treated and non-tocilizumab-treated patients, respectively (absolute risk difference, 9.6 per cent).
The beneficial effect of tocilizumab on survival was consistent across categories of age, sex, and illness severity, and was also observed in patients who either did or did not receive corticosteroids.
Notably, patients with a more rapid disease trajectory, defined as three days or fewer from symptom onset to ICU admission, benefited from tocilizumab to a greater extent than patients with a slower disease trajectory.
Despite the observational design, this study provides crucial and robust data on tocilizumab efficacy and safety in a large population of critically ill patients with Covid-19.
On average, there was a 30 per cent relative reduction in mortality for patients treated with tocilizumab in their first two days of ICU admission, there were no signs of increased risk for secondary infection, and there was only a small increase in the risk of liver function test abnormalities.
"We specifically focused on critically ill patients; we focused on an early use of tocilizumab (defined as the first two days of ICU admission), and we included a much larger number of patients," said study lead author Shruti Gupta from Brigham and Women's Hospital. "We hope that our findings stimulate further investigation of tocilizumab in Covid-19, particularly as we are seeing cases rise across the country," Gupta added.