Importance: Fostamatinib, a spleen tyrosine kinase inhibitor, has been reported to improve outcomes of COVID-19.
Objective: To evaluate the efficacy and safety of fostamatinib in adults hospitalized with COVID-19 and hypoxemia.
Design, Setting, And Participants: This multicenter, phase 3, placebo-controlled, double-blinded randomized clinical trial was conducted at 41 US sites and 21 international sites between November 17, 2021, and September 27, 2023; the last follow-up visit was December 31, 2023.
Background: The phase 2 ASUNCTIS study assessed the efficacy and safety of asunercept, a fully human CD95 (Fas) ligand-binding protein, in hospitalised patients with moderate-to-severe coronavirus disease (COVID-19) to assess the clinical benefit of CD95 ligand inhibition in this viral disease.
Methods: In this open-label, multicentre, randomised, controlled, phase 2 trial, patients with COVID-19-induced pneumonia and respiratory deterioration were randomly assigned (1:1:1:1) in 12 Russian and Spanish hospitals using an interactive web-response system to receive standard of care (SOC) or SOC plus weekly asunercept 25 mg, 100 mg, or 400 mg, administered intravenously for up to 4 weeks, or until hospital discharge or death. The randomisation was stratified according to the respiratory support methods at the time of enrolment, corresponding to categories 4-6 of a clinical severity assessment scale comprising 9 levels that was recommended by the World Health Organization (WHO) at the time of the study.