562 - Tocilizumab for the Treatment of Severe COVID-19: A Retrospective, Multi-Center, Case-Matched Series

Background: At the time of this writing, there is no FDA approved medication for the treatment of COVID-19. One medication currently under investigation for COVID-19 treatment is tocilizumab, an interleukin-6 (IL-6) inhibitor.  It has been shown there are increased levels of cytokines including IL-6 in severe COVID-19 hospitalized patients attributed to cytokine release syndrome (CRS). Therefore, inhibition of IL-6 receptors may lead to a reduction in cytokines and prevent progression of CRS. The purpose of this retrospective study is to utilize a case-matched design to investigate clinical outcomes associated with the use of tocilizumab in severe COVID-19 hospitalized patients.

Methods: This was a retrospective, multi-center, case-matched series matched 1:1 on age, BMI, and days since symptom onset. Inclusion criteria included ≥ 18 years of age, laboratory confirmed positive SARS-CoV-2 result, admitted to a community hospital from March 1^st – May 8^th, 2020, and received tocilizumab while admitted. The primary outcome was in-hospital mortality. Secondary outcomes included hospital length of stay, total mechanical ventilation days, mechanical ventilation mortality, and incidence of secondary bacterial or fungal infections.

Results: The following results are presented as tocilizumab vs control respectively. The primary outcome of in-hospital mortality for tocilizumab (n=26) vs control (n=26) was 10 (38%) vs 11 (42%) patients, p=0.777. The median hospital length of stay for tocilizumab vs control was 14 vs 11 days, p=0.275. The median days of mechanical ventilation for tocilizumab (n=21) vs control (n=15) was 8 vs 7 days, p=0.139, and the mechanical ventilation mortality was 10 (48%) vs 9 (60%) patients, p=0.463. In the tocilizumab group, for those expired (n=10) vs alive (n=16), 10 (100%) vs 7 (50%) patients respectively had a peak ferritin > 600 ng/mL, and 6 (60%) vs 8 (50%) patients had a peak D-dimer > 2,000 ng/mL. The incidence of secondary bacterial or fungal infections within 7 days of tocilizumab administration occurred in 5 (19%) patients.

Conclusion: These findings suggest that tocilizumab may be a beneficial treatment modality for severe COVID-19 patients. Larger, prospective, placebo-controlled trials are needed to further validate results.