505. Impact of Remdesivir on SARS-CoV-2 Clearance in a Real-Life Setting: A Matched-Cohort Study
Authors: Spagnuolo Vincenzo , Voarino Marta , Tonelli Marco , Galli Laura , Poli Andrea , Bruzzesi Elena , Racca Sara , Clementi Nicola , Oltolini Chiara , Tresoldi Moreno , Querini Patrizia Rovere , Dagna Lorenzo , Zangrillo Alberto , Ciceri Fabio , Clementi Massimo , Castagna Antonella 
Published: December 2021

Abstract

Background
Evidence regarding the impact of remdesivir (RDV) on SARS-CoV-2 viral clearance (VC) is scarce. Aim of this study was to compare VC timing in COVID-19 patients who received RDV with those who did not.

Methods
Matched-cohort study conducted (25 February 2020-15 April 2021) at the IRCSS San Raffaele, Milan, Italy. The study enrolled hospitalized patients with pneumonia and a SARS-CoV-2 positive nasopharyngeal swab (NPS) at admission and at least one NPS during follow-up. Follow-up started at hospital admission and ended at the date of the first negative NPS (within 30 days after discharge). Patients who received RDV (cases) and patients who did not (controls) were matched based on age (±5 years), sex and PaO2/FiO2 (P/F; ±10 mmHg) values at admission. NPS were analyzed with RT-PCR. Results described as median (IQR) or frequency (%). Time to VC was estimated with Kaplan-Meier curve and compared with log-rank test.

Results
648 patients were enrolled: 216 cases and 432 controls. Patients’ characteristics at admission are reported in Table 1. VC was observed in 490 patients (75.6%) in a median time of 25 (16-34) days. Overall, time to VC was similar in patients receiving or not receiving remdesivir (p=0.519). However, time to VC was different when considering both the use of RDV (yes vs no) and age (≤ or &gt; 63 years), as shown in Figure 1A. A significant finding was also observed considering the use of RDV and P/F values at admission (≤ or &gt; 200 mmHg), as reported in Figure 1B. Among the 490 patients who reached VC during follow-up, overall time to VC was similar in patients receiving or not receiving RDV (p=0.075; Figure 2A); however, RDV use was associated with a higher probability of VC in the subgroup of patients with P/F admission values ≤ 200mmHg (p=0.035; Figure 2B), in the age group 55-65 years (p=0.025; Figure 2C) and in patients with comorbidities (p=0.028).

Time to viral clearance among the 490 patients who reached VC during follow-up. Panel A: time to VC according to RDV use. Panel B: time to VC according to RDV and P/F ratio value at admission. Panel C: time to VC according to RDV in the age group 55-65 years.

Conclusion
Time to viral clearance was similar in patients receiving or not receiving remdesivir; however the use of RDV was associated with a benefit on time to viral clearance in younger patients and in those with a P/F ratio at admission ≤200 mmHg.

Disclosures
Vincenzo Spagnuolo, MD, ViiV Healthcare (Other Financial or Material Support, Preparation of educational material) Antonella Castagna, MD, Gilead Sciences (Other Financial or Material Support, Speaking fee)Jansenn-Cilag (Other Financial or Material Support, Speaking fee)MSD (Other Financial or Material Support, Speaking fee)Theratechnologies (Other Financial or Material Support, Speaking fee)ViiV Healthcare (Other Financial or Material Support, Speaking fee)