Fostamatinib for Hospitalized Adults With COVID-19 and Hypoxemia: A Randomized Clinical Trial

Abstract

Fostamatinib; COVID-19; Hypoxemia

Fostamatinib; COVID-19; Hipoxèmia

Fostamatinib; COVID-19; Hipoxemia

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. Participants were adults aged 18 years or older hospitalized with acute SARS-CoV-2 infection and hypoxemia. Data were analyzed between January 10 and March 8, 2024. Interventions Fostamatinib, 150 mg orally twice daily for 14 days, or placebo. Main Outcomes and Measures The primary outcome was oxygen-free days, an ordinal outcome classifying a participant’s status at day 28 based on mortality and duration of supplemental oxygen use. An adjusted odds ratio (AOR) greater than 1.0 was considered to indicate superiority of fostamatinib over placebo. A key secondary outcome was 28-day all-cause mortality. Safety outcomes included elevated transaminase values, neutropenia, and hypertension. Results Of the 400 participants randomized (median age, 67 years [IQR, 58-76 years]; 210 [52.5%] men), 199 received fostamatinib and 201 received placebo. The mean (SD) number of oxygen-free days was 13.4 (12.4) in the fostamatinib group and 14.2 (12.1) in the placebo group (unadjusted mean difference, −1.26 days [95% CI, −3.52 to 1.00 days]; AOR, 0.82 [95% credible interval (CrI), 0.58-1.17]). Mortality at 28 days occurred in 22 of 195 patients (11.3%) in the fostamatinib group and 16 of 197 (8.1%) in the placebo group (AOR, 1.44; 95% CrI, 0.72-2.90). Aspartate aminotransferase elevation occurred more commonly in the fostamatinib group (23 [11.6%]) than in the placebo group (11 [5.5%]; AOR, 2.28; 95% CrI, 1.07-4.84). Other safety outcomes were similar between groups. Conclusions and Relevance In this randomized clinical trial of adults hospitalized with COVID-19 and hypoxemia, fostamatinib did not increase the number of oxygen-free days compared with placebo. These results do not support the hypothesis that fostamatinib improves outcomes among adults hospitalized with hypoxemia during the Omicron era. Trial Registration ClinicalTrials.gov Identifier: NCT04924660

This research was funded by awards 42-312-0217571-66406L and 1OT2HL156812 from the NHLBI, NIH and by award 1OT2HL156812 from the NHLBI through the Collaborating Network of Networks for Evaluating COVID-19 and Therapeutic Strategies program. This research was supported in part by the Intramural Research Program of the NIH and the NHLBI. The REDCap data tools used for this research were supported by grant UL1TR002243 from the National Center for Advancing Translational Sciences. Fostamatinib was supplied by Rigel Pharmaceuticals.