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.