Severe Neutropenia after Sarilumab Administration in Two COVID-19 Patients: Case Reports and Literature Review

Abstract

BACKGROUND: Two years have passed since the WHO declared a pandemic state for SARS-CoV2 infection. COVID-19 pathogenesis consists of a first viral phase responsible for early symptoms followed by an inflammatory phase, which is cytokine-mediated, responsible for late-onset signs up to acute respiratory distress syndrome. Considering that interleukin (IL)6 plays a key role in the development and maintenance of inflammation, drugs targeting both IL6 and IL6 receptors have been evaluated. CASE REPORTS: The present study reports the cases of two hospitalized patients with severe respiratory COVID-19 treated with a single dose of intravenous sarilumab, a monoclonal anti-IL6 antibody, along with standard of care medications and high-flow oxygen therapy. Although a few days following sarilumab administration, clinical and biochemical conditions started ameliorating, these patients developed severe and self-limiting neutropenia. CONCLUSION: Sarilumab may represent a promising weapon to treat the fearsome hyperinflammatory phase; however, more trials are needed to decide whether to use it in combination with other drugs or alone, and to better understand pharmacokinetics and side effects.