Exploration of the optimal GS-441524 trough concentration for treating COVID-19.

• GS-441524 trough ≥70 ng/mL leads to symptom improvement in COVID-19 pneumonia. • Probability of GS-441524 trough ≥70 ng/mL was associated with eGFR and BMI. • An individualised remdesivir dosing schedule may optimise its efficacy. Remdesivir (RDV) is the cornerstone for treating coronavirus disease 2019 (COVID-19). The active metabolite of RDV, GS-441524 (a nucleoside analogue), has high interindividual variability in plasma concentrations; however, its concentration–response relationship is still unclear. This study investigated the target GS-441524 trough concentration for symptom improvement in COVID-19 pneumonia. This single-center, retrospective, observational study included Japanese patients (age ≥15 years) with COVID-19 pneumonia who were administered RDV for ≥3 days from May 2020 to August 2021. To determine the cut-off value of GS-441524 trough concentration on Day 3, achievement of the National Institute of Allergy and Infectious Disease Ordinal Scale (NIAID-OS) ≤3 after RDV administration was evaluated using the cumulative incidence function (CIF) with the Gray test and time-dependent receiver operating characteristic (ROC) analysis. Multivariate logistic regression analysis was performed to determine factors influencing GS-441524 target trough concentrations. The analysis comprised 59 patients. The CIF revealed that GS-441524 trough concentration ≥70 ng/mL was associated with the achievement of NIAID-OS ≤3 (P = 0.047), which was significant based on the time-dependent ROC analysis. Factors influencing GS-441524 trough concentration ≥70 ng/mL included a decrease in estimated glomerular filtration rate (eGFR) [adjusted odds ratio (aOR) = 0.96, 95% confidence interval (CI) 0.92–0.99; P = 0.027] and BMI ≥25 kg/m2 (aOR = 0.26, 95% CI 0.07–0.86; P = 0.031). GS-441524 trough concentration ≥70 ng/mL is a predictor of efficacy in COVID-19 pneumonia. The presence of lower eGFR or BMI ≥25 kg/m2 was associated with achieving GS-441524 trough concentration ≥70 ng/mL. [ABSTRACT FROM AUTHOR]