ABSTRACT
Remdesivir is a broad-spectrum antiviral agent able to inhibit the RNA polymerase of SARS-CoV-2. At present, studies focusing on the effect of remdesivir on viral load (VL) are few and with contrasting results. Aim of the present study was to evaluate the effect of remdesivir on SARS-CoV-2 VL from nasopharyngeal swabs (cycle threshold criterion) in a sample of patients treated with the drug, compared with patients who did not receive the antiviral treatment. This retrospective analysis evaluated patients with (1) real-time polymerase chain reaction (RT-PCR) confirmed COVID-19 diagnosis and (2) availability of at least two positive nasopharyngeal swabs analysed with the same analytic platform (ORF target gene, Ingenius ELITe, ELITechGroup, Puteaux, France). Upper respiratory specimens from nasopharyngeal swabs were collected at admission (T0) and 7-14 days after treatment, upon clinical decision. A total of 27 patients treated with remdesivir (Group A) met the inclusion criteria and were compared with 18 patients (Group B) treated with standard care, matched for baseline clinical characteristics. At baseline, both remdesivir-treated and nontreated patients showed comparable VLs (21.73 ± 6.81 vs. 19.27 ± 5.24, p = 0.348). At the second swab, remdesivir-treated patients showed a steeper VL reduction with respect to controls (34.28 ± 7.73 vs. 27.22 ± 3.92; p < 0.001). Longitudinal linear model estimated a mean decrease in cycle threshold equal to 0.61 (SE: 0.09) per day in remdesivir-treated versus 0.33 (SE: 0.10) per day in remdesivir nontreated patients (p for heterogeneity = 0.045). The present study shows that the administration of remdesivir in hospitalized COVID-19 patients significantly reduces the VL on nasopharyngeal swabs.