505. Impact of Remdesivir on SARS-CoV-2 Clearance in a Real-Life Setting: A Matched-Cohort Study

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 > 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 > 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)

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 > 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 > 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) Background. Monoclonal Antibodies directed at the spike protein of SARS-COV-2 are approved by the FDA for Emergency Use for outpatients with COVID-19 who are at risk for severe complications. Here we present a single center experience using Bamlanivimab and Casirivimab/Imdevimab to prevent hospitalizations due to SARS-COV-2.

Outpatient Bamlanivimab, Casirivimab and
Methods. Adult patients who tested positive for SARS-COV-2 in our health system were offered outpatient monoclonal antibody infusion if: (1) testing was done within the previous 7 days, (2) the patient had fewer than 10 days of symptoms, (3) the patient was not currently hospitalized, and (4) met at least 1 of 8 criteria in the FDA EUA Fact Sheet for Bamlanivimab and Casirivimab/Imdevimab. Patients who met the criteria were offered the monoclonal antibody available at time of infusion. Those who declined antibody infusion were used as potential controls. The primary outcome was the discrepancy in hospitalization rates at 14-days past the infusion date for patients receiving the monoclonal antibody regimen versus 14-days past when those in control group would have been scheduled for infusion had they accepted. Secondary outcomes included emergency room visits, duration of hospitalization, and Intensive Care Unit stays. Coarsened exact matching (CEM) was used to obtain balance between treatment and control groups. A logistic regression model measured statistical differences between the groups.
Results. Between November 23, 2021 and February 8, 2021, 5567 patients were offered a monoclonal antibody infusion. A total of 894 patients completed infusion who were able to be matched with patients in the control group. Patients who received the infusion were statistically less likely to be hospitalized than those who did not receive the infusion (2.68% vs 6.70%, p< 0.001).
Conclusion. This feasibility study shows reduction in hospitalization in patients who received monoclonal antibody versus standard care. It provides real-world information regarding using monoclonal antibodies as a tertiary prevention strategy to limit the progression of SARS-CoV2 infections, which will lead to improved clinical outcomes and decreased healthcare costs.
Disclosures. Background. There is a lack of data specifically addressing the effects of triple therapy consisting of baricitinib plus remdesivir plus dexamethasone compared to dual therapy with remdesivir plus dexamethasone among patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pneumonia.