Remdesivir: Real-World Effectiveness and Safety in Individuals Hospitalized for Non-COVID Reasons and Non-Hospitalized High-Risk Patients During the Omicron Era in Greece.

Remdesivir is recommended for hospitalized patients with severe COVID-19 and for those at high risk of progression. Real-world Omicron-era data on incidental COVID-19 and high-risk outpatients remain limited. We conducted a multicenter retrospective cohort study (ReEs-COVID19) in Greece (June-December 2022) including adults with PCR-confirmed SARS-CoV-2 infection who received remdesivir. Hospitalized patients with incidental COVID-19 (Group A, n = 138) and high-risk outpatients (Group B, n = 312) were analysed. Outcomes included clinical deterioration, mortality, and adverse events. Group A patients were older with more comorbidities. Remdesivir was initiated earlier in Group A (median 1 vs. 2 days) but with a more heterogeneous duration (48.9% vs. 97.8% in Group B, which received the standard 3-day regimen). Clinical deterioration due to COVID-19 occurred in 5.8% vs. 0.6%, and 30-day mortality was 18.1% (25/138) in Group A, including 10 COVID-19-related deaths (7.2%). Group B had two deaths (0.6%), none COVID-19-related. Adverse events were uncommon, with mild kidney injury in 3.6% of Group A and hepatotoxicity in 2.2% vs. 0.3%. In high-risk outpatients, the ReEs-COVID19 study confirmed the effectiveness and safety of remdesivir's profile. Among incidental cases, two distinct disease patterns were identified, associated with different remdesivir regimens and highlighting the importance of comorbidities and the need for tailored clinical interventions.