Effects of Siltuximab Versus Corticosteroids in Preventing <scp>COVID</scp> −19 Pneumonia Disease Progression: Multicentre, Open‐Label, Randomized Clinical Trial

In 2020, COVID-19 caused a global health crisis, prompting research efforts and accelerating drug development. As part of this response, we conducted a phase 2b, multicentre, open-label, randomized (1:1) clinical trial to compare the effects of siltuximab versus corticosteroids on disease progression in hospitalized adults with COVID-19 pneumonia. Between April 2020 and January 2021, 82 patients were randomized to receive siltuximab and 80 corticosteroids (20 methylprednisolone and 60 dexamethasone). Median (IQR) age was 61 years (50-72). Nineteen patients allocated to siltuximab were admitted to the intensive care unit compared to eight receiving corticosteroids (p = 0.025). Corticosteroid treatment was independently associated with a higher risk of avoiding intensive care unit admission (2.7; 95% CI, 1.11-6.62), lower risk of requiring mechanical ventilation (0.43; 95% CI, 0.20-0.93) and shorter hospitalization duration (p = 0.008). Mortality was similar between arms (p = 0.675). Twenty-eight patients receiving siltuximab required rescue therapy while only 5 receiving corticosteroids (p < 0.001). Furthermore, patients receiving corticosteroids had a 53% lower risk of confirmed bacterial or fungal invasive infections (RR 0.47; 95% CI, 0.23-0.95; p = 0.0096). Our results show that initial treatment with corticosteroids was more effective than siltuximab in preventing disease progression, reducing intensive care unit admission, mechanical ventilation, with shorter hospital stays, and fewer infection in COVID-19 pneumonia. Despite numerous challenges, these findings provide valuable insights into optimizing therapeutic strategies, supporting corticosteroids as a preferred treatment over siltuximab in this setting.