Tocilizumab not associated with increased infection risk after CAR T-cell therapy: implications for COVID-19?

As of 28 April 2020, COVID-19 has been confirmed in 2.9 million people worldwide, with an estimated overall global mortality of up to 6.9%; it is even higher (up to 50%) in older populations with comorbidities. Healthcare systems around the world are stretched to the point of collapse, with no treatment proven to be effective. There is an urgent need for therapeutic interventions that can reduce the rate of respiratory failure, the leading cause of mortality. The current focus is on the development of novel antiviral therapeutics, as well as vaccines. Accumulating evidence suggests that a subgroup of patients with COVID-19 develops a severe inflammatory response akin to macrophage activation syndrome (MAS)/hemophagocytic lympho-histiocytosis (HLH), orchimeric antigen receptor (CAR) T-cell–mediated cytokine release syndrome (CRS), which may contribute to the acute respiratory distress syndrome (ARDS) seen in up to 20% of patient. Antibody therapies to block cytokines are used in the management of CRS in other settings and are highly effective. This approach may be useful to decrease pulmonary inflammation in patients suffering from COVID-19, but there is concern about the potential for increasing direct infection-related morbidity and mortality