Activity of sotrovimab in early clearance of SARS CoV-2 infection in severe immunocompromised patients: results of a prospective, monocentric study.

Background: The combination of antivirals and monoclonal antibodies (mAbs) in the first phase of COVID-19 has demonstrated to reduce time to viral clearance, but the superiority of combination compared to antiviral monotherapy is still debated.

Research Design And Methods: In an observational, prospective study, we enrolled immunocompromised outpatients with mild-to-moderate COVID-19 treated with one antiviral monotherapy within 7 days from symptoms onset, with or without sotrovimab from January 1, 2024 to October 31, 2024, and we compared them to an identical cohort of patients treated with a combination of one antiviral and sotrovimab, from May 1, 2023 to December 30, 2023. 1st of May 2023 and 31st of October 2024. Sotrovimab administered until the end of October 2023 was considered to be presumably effective against the circulating viral variants, based on virological reports.

Results: We enrolled considered 98 patients treated with nirmatrelvir/ritonavir or remdesivir. Sotrovimab was co-administered in 50/98 cases. All the patients cleared SARS-CoV-2 infection within a median of 17 (IQR 10-22) days. At the multivariate Cox regression analysis, therapy administration within 3 days from symptoms' onset (aHR 1.68;  = 0.031) and presumed sotrovimab effectiveness (aHR 1.75;  = 0.02) were found to be independent factors associated with for shorter time to viral clearance.

Conclusions: The timing of administration of early antiviral therapy is crucial to reduce SARS-CoV-2 infection duration in immunocompromised patients and the combination with a mAb is associated with earlier viral clearance, as long asmAb is chosen among those effective against circulating variants.