Outcomes of Tocilizumab Therapy in Severe or Critical COVID-19 Patients: A Retrospective Cohort, Single-Center Study

Abdelnaby, Hassan; Aboelhassan, Wael; Al-Jarallah, Mohammed; Rajan, Rajesh; Dashti, Raja; Al Saber, Ahmad R; Abd El-Saleem, Ahmed; Ashri, Islam; Abdullah, Mohammed; Mahmud Fouad, Ahmed

OBJECTIVES: To assess the effectiveness and safety of tocilizumab, a humanized anti-interleukin-6 receptor antibody, in the treatment of critical or severe coronavirus disease 2019 (COVID-19) patients. METHODS: This was a retrospective cohort study of severe or critical COVID-19 patients (≥18 years) admitted to one hospital in Kuwait. Fifty-one patients received intravenous tocilizumab, while 78 patients received the standard of care at the same hospital. Both groups were compared for clinical improvement and in-hospital mortality. RESULTS: The tocilizumab (TCZ) group had a significantly lower 28-day in-hospital mortality rate than the standard of care group (21.6% vs. 42.3%, respectively; p= 0.015). 55% of patients in the TCZ group clinically improved vs. 11.5% in the standard-of-care group (p< 0.001). Using Cox-proportional regression analysis, TCZ treatment was associated with a reduced risk of mortality (adjusted hazard ratio 0.25; 95% CI: 0.11 - 0.61) and increased likelihood of clinical improvement (adjusted hazard ratio 4.94; 95% CI: 2.03 - 12.0), compared to the standard of care. The median C-reactive protein, D-dimer, procalcitonin, lactate dehydrogenase, and ferritin levels in the tocilizumab group decreased significantly over the 14 days of follow-up. Secondary infections occurred in 19.6% of the TCZ group, and in 20.5% of the standard-of-care group, with no statistical significance (p =0.900). CONCLUSION: Tocilizumab was significantly associated with better survival and greater clinical improvement in severe or critical COVID-19 patients.