MATIS Trial

Standard of care evolved substantially over the trial period, complicating between-arm and temporal comparisons. Approximately one-third of participants in each active treatment arm did not complete the 14-day treatment course. The trial was halted in September 2022 due to declining COVID-19 hospitalisations driven by mass vaccination, leaving the final analysis substantially underpowered. At the Stage 1 interim analysis, fostamatinib showed no evidence of benefit and was stopped for futility. Final results are hypothesis-generating only because the trial was substantially underpowered. MATIS was an adaptive, open-label, three-arm, two-stage randomised controlled trial conducted at five hospitals in England between October 2020 and September 2022. The majority of MATIS participants were enrolled at a single large London teaching hospital, limiting generalisability.