Comparative Analysis of Early COVID-19 Treatment Efficacy in a Multicentric Regional Cohort in Italy: Emulation of a Series of Target Trials

Studies comparing all available strategies for the early treatment of mild-to-moderate COVID-19 during the Omicron era are lacking. We included people with mild-to-moderate COVID-19 and at high risk of progressing to severe disease attending five outpatient clinics in Italy over 2022–2023. The primary outcome was the proportion of participants who experienced Day-30 hospitalization due to COVID-19 or death. Participants received either nirmatrelvir/ritonavir (NMV/r), molnupiravir (MLP), remdesivir (RDV), sotrovimab (SOT), or tixagevimab/cilgavimab (TIX/CIL). We included 10 038 individuals: females 5052 (50%), median age 71 years (IQR 59–81). In total, 1919 (19%) received SOT, 3732 (37.2%) MLP, 1444 (14%) RDV, 2510 (25%) NMV/r, and 433 (4%) TIX/CIL. Only 1689 (17%) had incomplete vaccination, and 2435 (24.3%) were not immunocompetent. The rate of hospitalization/death was 2.40% (95% CI 2.10–2.71). Unadjusted rates were 0.88% (95% CI 0.55–1.32) for NMV/r, 1.69% (95% CI 1.30–2.15) for MLP, 3.0% (95% CI 1.61–5.08) for TIX/CIL, 3.54% (95% CI 2.76–4.47) for SOT and 5.12% (95% CI 4.05–6.39) for RDV. Weighted analysis showed that NMV/r and MLP were superior to all other interventions. In our population of individuals at high risk of progression to severe disease, there was clinical benefit in using NMV/r or MLP instead of mAbs-based therapies or RDV.