Survival and outcomes of tocilizumab use in severe and critically ill COVID-19 patients not responding to steroids

Abstract

Background Mortality and morbidity are highest in severe and critically ill patients with COVID -19 pneumonia. Recently corticosteroids have shown a definite mortality benefit in these patients. In this study we used interleukin -6 inhibitor, tocilizumab in patients who failed to show any clinical improvement after initial treatment with steroids. Patients and methods This is a retrospective observational study conducted at a tertiary care referral hospital in India. Severe and critical COVID 19 patients , who got admitted to intensive care unit and subsequently received tocilizumab were included . Patients who worsened clinically or had no change in oxygen requirement even after 24hrs of receiving Intravenous methylprednisolone at a dose of 1-2mg/kg/day received a maximum total dose of 800mg of intravenous tocilizumab. The day 28 all cause mortality and progression to mechanical ventilation were the primary outcome measures. Clinical improvement and oxygen requirements after tocilizumab administration along with trends in inflammatory markers were secondary outcome.Secondary infections rates and other drug related side effects were also noted. Results A total of 51 patients who did not show clinical improvement even after 24 hours of intravenous steroids and received tocilizumab were included. In these patients, there was a significant decrease in oxygen requirement by day 3 and clinical improvement by day 7 of tocilizumab administration. Among the inflammatory markers, we observed elevated median baseline values of CRP (114.2 mg/L) , IL-6 (55.4 pg/ml) and Neutrophil to Lymphocyte Ratio (12.4). Out of these only CRP showed a significant decrease after the drug administration. 13 (26.5%) of the 49 patients who were on non-invasive or conventional oxygen support progressed to mechanical ventilation. The day 28 all-cause mortality rate was 10/51(19.6%). 10(19.6%) of the 51 patients had life threatening infections, 5/51 had thrombocytopenia, 3/51 had pneumo-mediastenum/pneumothorax, 1 patient had colonic perforation and 1 patient had transaminitis following tocilizumab administration. Conclusion Early and timely administration of tocilizumab only in selected severe and critical covid patients not responding to initial steroids appears to increase the survival. This needs to be further confirmed by randomised controlled trials. When given along with steroids, incidence of life threatening infections seems to increase, hence a high suspicion of secondary infection should be kept.