* patients who require mechanical ventilation at the time of inclusion. * ast / alt values \> 5 folds upper normal limit. * neutrophil count below 500 cells / mm3 * platelet count below 50,000 cells / mm3 * documented sepsis or high suspicion by pathogens other than covid-19. * presence of comorbidities that according to clinical judgment could lead to an unfavorable result. * complicated diverticulitis or intestinal perforation. * current skin infection (eg, uncontrolled dermopiodermitis). * immunosuppressive anti-rejection therapy. * pregnancy or lactation. * previous treatment with tocilizumab or sarilumab. * patients participating in some other clinical trial for sars-cov-2 infection. * patients with known hypersensitivity or contraindication to sarilumab or excipients.

* patients who require mechanical ventilation at the time of inclusion. * ast / alt values \> 5 folds upper normal limit. * neutrophil count below 500 cells / mm3 * platelet count below 50,000 cells / mm3 * documented sepsis or high suspicion by pathogens other than covid-19. * presence of comorbidities that according to clinical judgment could lead to an unfavorable result. * complicated diverticulitis or intestinal perforation. * current skin infection (eg, uncontrolled dermopiodermitis). * immunosuppressive anti-rejection therapy. * pregnancy or lactation. * previous treatment with tocilizumab or sarilumab. * patients participating in some other clinical trial for sars-cov-2 infection. * patients with known hypersensitivity or contraindication to sarilumab or excipients.

- patients who require mechanical ventilation at the time of inclusion. - ast / alt values > 5 folds upper normal limit. - neutrophil count below 500 cells / mm3 - platelet count below 50,000 cells / mm3 - documented sepsis or high suspicion by pathogens other than covid-19. - presence of comorbidities that according to clinical judgment could lead to an unfavorable result. - complicated diverticulitis or intestinal perforation. - current skin infection (eg, uncontrolled dermopiodermitis). - immunosuppressive anti-rejection therapy. - pregnancy or lactation. - previous treatment with tocilizumab or sarilumab. - patients participating in some other clinical trial for sars-cov-2 infection. - patients with known hypersensitivity or contraindication to sarilumab or excipients.

- patients who require mechanical ventilation at the time of inclusion. - ast / alt values > 5 folds upper normal limit. - neutrophil count below 500 cells / mm3 - platelet count below 50,000 cells / mm3 - documented sepsis or high suspicion by pathogens other than covid-19. - presence of comorbidities that according to clinical judgment could lead to an unfavorable result. - complicated diverticulitis or intestinal perforation. - current skin infection (eg, uncontrolled dermopiodermitis). - immunosuppressive anti-rejection therapy. - pregnancy or lactation. - previous treatment with tocilizumab or sarilumab. - patients participating in some other clinical trial for sars-cov-2 infection. - patients with known hypersensitivity or contraindication to sarilumab or excipients.