The impact of early versus late tocilizumab administration in patients with cytokine release syndrome secondary to immune effector cell therapy.

INTRODUCTION: Cytokine release syndrome is a life-threatening hyper-inflammatory state induced by immune effector cell therapy. Anti-interleukin 6-(IL-6) therapy, such as tocilizumab, is the standard treatment for cytokine release syndrome since it reverses symptoms without compromising immune effector cell therapy efficacy. Glucocorticoids are reserved for refractory or severe cytokine release syndrome due to concern for attenuating antitumor activity. Optimizing the timing of tocilizumab could avoid glucocorticoid use and improve outcomes. This study assesses tocilizumab timing on patient outcomes and healthcare resource utilization. METHODS: This is a retrospective single-institution analysis of 28 patients who received tocilizumab for cytokine release syndrome secondary to immune effector cell therapy. Patients were categorized into two groups: Early Tocilizumab (within 24 h) or Late Tocilizumab groups (more than 24 h) from fever onset. The composite primary endpoint was glucocorticoid use, intensive care unit admission, or inpatient mortality. Secondary outcomes include comparing the various presentations of cytokine release syndrome, need for vasopressors, length of stay, rates of neurotoxicity, and C-reactive protein and ferritin trends. RESULTS: The Early Tocilizumab group presented with more rapid fever onset (35 vs.113 h, P = 0.017) and higher maximum cytokine release syndrome grade (Median, Grade 2 vs. Grade 1, P = 0.025). Additionally, the Early Tocilizumab group required more doses of tocilizumab (Median, 2 vs. 1, P = 0.037). Despite the difference in cytokine release syndrome presentation, the primary composite endpoint was not statistically different between groups. CONCLUSION: Earlier onset of fever appears to be associated with more severe, progressive cytokine release syndrome requiring multiple doses of anti-interleukin-6 therapy. Prompt and aggressive tocilizumab treatment could be protective against the negative consequences of cytokine release syndrome.