Population pharmacokinetic modeling of GS-441524, the active metabolite of remdesivir, in Japanese COVID-19 patients with renal dysfunction

Pharmacokinetics of GS-441524, the active metabolite of remdesivir, in patients receiving continuous renal replacement therapy: A case series

Remdesivir plays a key role in the treatment of coronavirus disease in 2019 (COVID-19). Haemodialysis is sometimes required for hospitalised patients with COVID-19, and patients undergoing haemodialysis are at an increased risk of severe COVID-19. In the present study, we report the serum concentrations of GS-441524, the active metabolite of remdesivir, in four patients undergoing continuous renal replacement therapy (CRRT). Patient 1, a male aged 70s, received a loading dose of 200 mg remdesivir on day 1, followed by 100 mg remdesivir from day 2, according to the package insert as in non-haemodialysis patients. The mean trough serum concentration of GS-441524 was 783.5 ng/mL, which was approximately 7-fold higher than the mean for patients with an estimated glomerular filtration rate (eGFR) ≥ 60 mL/min. Patients 2-4 received a loading dose of 200 mg remdesivir on day 1, followed by 100 mg once every 2 days from day 2. The mean trough serum concentrations of GS-441524 were 302.2 ng/mL, 585.8 ng/mL and 677.3 ng/mL, respectively. These were 3 to 6-fold higher than the mean for patients with eGFR ≥60 mL/min. The target doses for patients 1, 2, 3, and 4 receiving CRRT were 13.6 mL/kg/h, 6.0-12.5 mL/kg/h, 20.1 mL/kg/h, and 15.1 mL/kg/h, respectively, using a polysulphone membrane. The package insert dose of remdesivir is an overdose for CRRT patients with a target dose of 10-20 mL/kg/h. In low-intensity CRRT, as in Japan, it may be necessary to extend the interval between the doses of remdesivir.

Transient Lactic Acidosis and Elevation of Transaminases after the Introduction of Remdesivir in a Patient with Acute Kidney Injury

A 56-year-old woman was transferred to the intensive care unit (ICU) two days after an allogeneic stem cell transplantation (ASCT) when she presented acute respiratory distress due to the relapse of a SARS-CoV-2 infection. Following that, she received two intravenous doses of 100 mg remdesivir. Subsequently, the patient developed multiple instances of diarrhea, progressing to oliguria and acute kidney injury, necessitating continuous venovenous hemofiltration (CVVH). Despite the absence of signs of hypoxemia or cardiocirculatory failure requiring vasopressor intervention, a progressive lactic acidosis emerged. Two days after the onset of lactic acidosis, a significant rise in aminotransferases and lactate dehydrogenase occurred, in the absence of encephalopathy and coagulation disorders. Remdesivir therapy had been interrupted upon the initial signs of lactic acidosis. Despite an improvement in liver function tests and lactic acidosis, the patient's condition deteriorated, ultimately leading to her demise on day 29 due to newly arising hematological complications.

Population pharmacokinetics and exposure-clinical outcome relationship of remdesivir major metabolite GS-441524 in patients with moderate and severe COVID-19

Although remdesivir, a prodrug of nucleoside analog (GS-441524), has demonstrated clinical benefits in coronavirus disease 2019 (COVID-19) treatment, its pharmacokinetics (PKs) in patients with COVID-19 remain poorly understood. Therefore, in this study, the PKs of remdesivir and its major metabolite, GS-441524, were evaluated using a population PK (PopPK) approach to understand the PK aspect and exposure-clinical outcome relationship. The serum concentrations of remdesivir and GS-441524 (102 points in 39 patients) were measured using liquid chromatography-tandem mass spectrometry. All patients received 200 mg remdesivir on the first day, followed by 100 mg on 2-5 days, except for one patient who discontinued remdesivir on day 4. The median (range) age, body surface area, and estimated glomerular filtration rate (eGFR) were 70 (42-85), 1.74 m² (1.36-2.03), and 68 mL/min/1.73 m² (33-113), respectively. A compartment model with first-order elimination combined with remdesivir and GS-441524 was used for nonlinear mixed-effects model analysis. Remdesivir was rapidly eliminated after infusion, whereas GS-441524 was eliminated relatively slowly (half-time = 17.1 h). The estimated apparent clearance (CL) and distribution volume of GS-441524 were 11.0 L/h (intersubject variability [ISV]% = 43.0%) and 271 L (ISV% = 58.1%), respectively. The CL of GS-441524 was significantly related to the eGFR (CL × [eGFR/68]^0.745 ). The post hoc area under the curve of GS-441524 was unrelated to the recovery rate or aspartate aminotransferase/alanine aminotransferase elevation. Overall, PopPK analysis showed the rapid elimination of remdesivir in the blood, and GS-441524 accumulation depended on eGFR in patients with COVID-19. However, no relevance of exposure-clinical outcome was not suggestive of the dose adjustment of remdesivir.

Therapeutic advances in COVID-19

Over 2 years have passed since the start of the COVID-19 pandemic, which has claimed millions of lives. Unlike the early days of the pandemic, when management decisions were based on extrapolations from in vitro data, case reports and case series, clinicians are now equipped with an armamentarium of therapies based on high-quality evidence. These treatments are spread across seven main therapeutic categories: anti-inflammatory agents, antivirals, antithrombotics, therapies for acute hypoxaemic respiratory failure, anti-SARS-CoV-2 (neutralizing) antibody therapies, modulators of the renin-angiotensin-aldosterone system and vitamins. For each of these treatments, the patient population characteristics and clinical settings in which they were studied are important considerations. Although few direct comparisons have been performed, the evidence base and magnitude of benefit for anti-inflammatory and antiviral agents clearly outweigh those of other therapeutic approaches such as vitamins. The emergence of novel variants has further complicated the interpretation of much of the available evidence, particularly for antibody therapies. Importantly, patients with acute and chronic kidney disease were under-represented in many of the COVID-19 clinical trials, and outcomes in this population might differ from those reported in the general population. Here, we examine the clinical evidence for these therapies through a kidney medicine lens.

A population pharmacokinetic model of remdesivir and its major metabolites based on published mean values from healthy subjects

Remdesivir is a direct-acting anti-viral agent. It was originally evaluated against filoviruses. However, during the COVID-19 pandemic, it was investigated due to its anti-viral activities against (SARS-CoV-2) virus. Therefore remdesivir received conditional approval for treatment of patients with severe coronavirus disease. Yet, its pharmacokinetic properties are inadequately understood. This report describes the population pharmacokinetics of remdesivir and its two plasma-detectable metabolites (GS-704277 and GS-441524) in healthy volunteers. The data was extracted from published phase I single escalating and multiple i.v remdesivir dose studies conducted by the manufacturer. The model was developed by standard methods using non-linear mixed effect modeling. Also, a series of simulations were carried out to test suggested clinical doses. The model describes the distribution of remdesivir and each of its metabolites by respective two compartments with sequential metabolism between moieties, and elimination from central compartments. As individual data were not available, only inter-cohort variability could be assessed. The estimated point estimates for central (and peripheral) volumes of distribution for remdesivir, GS-704277, and GS-441524 were 4.89 L (46.5 L), 96.4 L (8.64 L), and 26.2 L (66.2 L), respectively. The estimated elimination clearances of remdesivir, GS704277, and GS-441524 reached 18.1 L/h, 36.9 L/h, and 4.74 L/h, respectively. The developed model described the data well. Simulations of clinically approved doses showed that GS-441524 concentrations in plasma exceeded the reported EC₅₀ values during the complete duration of treatment. Nonetheless, further studies are needed to explore the pharmacokinetics of remdesivir and its relationship to clinical efficacy, and the present model may serve as a useful starting point for additional evaluations.

Safety Evaluation of Remdesivir for COVID-19 Patients with eGFR < 30 mL/min without Renal Replacement Therapy in a Japanese Single-Center Study

There are limited reports on the safety of remdesivir for patients with severe kidney disease. We investigated the safety of remdesivir administration for COVID-19 patients with estimated glomerular filtration rate (eGFR) <30 mL/min. This single-center retrospective study was conducted between March 2020 and April 2022 at Tosei General Hospital, Japan. Propensity score matching was performed between patients with eGFR ≤ 30 mL/min and eGFR >30 mL/min with remdesivir administration. The primary outcome was 30-day mortality after the first administration. Adverse events, including development of acute kidney injury (AKI), liver function disorder, anemia, and thrombocytopenia 48 h after the end of remdesivir administration, were evaluated. After propensity score matching, 23 patients were selected from each group. There were no differences in the 30-day mortality (risk ratio [RR] 1.00; 95% confidence interval [CI] 0.18−5.56). Development of AKI and liver function disorder was not statistically different between the two groups (RR 1.05; 95% CI 0.96−1.14 and RR 0.48; 95% CI 0.04−5.66, respectively). There was no trend toward a significant increase in adverse events in the eGFR < 30 mL/min group and severe renal dysfunction had little effect on the safety of remdesivir treatment.

Remdesivir in treating hospitalized patients with COVID-19: A renewed review of clinical trials

Since December 2019, COVID-19 has spread across the world almost through 2.5 years. As of 16 June 2022, the cumulative number of confirmed cases of COVID-19 worldwide has reached 542.62 million, and the death toll has risen to 6.33 million. With the increasing number of deaths, it is urgent to find effective treatment drugs. Remdesivir, an investigational broad-spectrum antiviral drug produced by Gilead has been shown to inhibit SARS-CoV-2, in vitro and in vivo. This review is aimed to analyze the feasibility of remdesivir in COVID-19 and put forward the shortcomings of present clinical studies. We systematically searched PubMed and Web of Science up until 24 May 2022, using several specific terms such as “remdesivir” or “GS-5734” and “COVID-19” or “SARS-CoV-2” and retrieved basic researches and clinical studies of remdesivir in COVID-19. In this review, we summarized and reviewed the mechanism of remdesivir in SARS-COV-2, clinical trials of using remdesivir in COVID-19, analyzed the efficacy and safety of remdesivir, and judged whether the drug was effective for the treatment of COVID-19. In different clinical trials, remdesivir showed a mixed result in the treatment of COVID-19. It seemed that remdesivir shortened the time to recovery and had an acceptable safety profile. However, more clinical trials are needed to test the efficacy and safety of remdesivir.

Interpatient variability in the pharmacokinetics of remdesivir and its main metabolite GS-441524 in treated COVID-19 subjects

Background

Remdesivir is the first antiviral drug against SARS-CoV-2 approved for use in COVID-19 patients.

Objectives

To study the pharmacokinetic inter-individual variability of remdesivir and its main metabolite GS-441524 in a real-world setting of COVID-19 inpatients and to identify possible associations with different demographic/biochemical variables.

Methods

Inpatients affected by SARS-CoV-2 infections, undergoing standard-dose remdesivir treatment, were prospectively enrolled. Blood samples were collected on day 4, immediately after (C₀) and at 1 h (C₁) and 24 h (C₂₄) after infusion. Remdesivir and GS-441524 concentrations were measured using a validated UHPLC-MS/MS method and the AUC_0–24 was calculated. At baseline, COVID-19 severity (ICU or no ICU), sex, age, BMI and renal and liver functions were assessed. Transaminases and estimated glomerular filtration rate (e-GFR) were also evaluated during treatment. Linear regression, logistic regression and multiple linear regression tests were used for statistical comparisons of pharmacokinetic parameters and variables.

Results

Eighty-five patients were included. The mean (CV%) values of remdesivir were: C₀ 2091 (99.1%) ng/mL, C₁ 139.7 (272.4%) ng/mL and AUC_0–24 2791 (175.7%) ng·h/mL. The mean (CV%) values of GS-441524 were: C₀ 90.2 (49.5%) ng/mL, C₁ 104.9 (46.6%) ng/mL, C₂₄ 58.4 (66.9) ng/mL and AUC_0–24 1976 (52.6%) ng·h/mL. The multiple regression analysis showed that age (P < 0.05) and e-GFR (P < 0.01) were independent predictors of GS-441524 plasma exposure.

Conclusions

Our results showed a high interpatient variability of remdesivir and GS-441524 likely due to both age and renal function in COVID-19 inpatients. Further research is required to understand whether the pharmacokinetics of remdesivir and its metabolites may influence drug-related efficacy or toxic effect.

Population Pharmacokinetics of Remdesivir and GS-441524 in Hospitalized COVID-19 Patients

The objective of this study was to describe the population pharmacokinetics of remdesivir and GS-441524 in hospitalized coronavirus disease 2019 (COVID-19) patients. A prospective observational pharmacokinetic study was performed in non-critically ill hospitalized COVID-19 patients with hypoxemia. For evaluation of the plasma concentrations of remdesivir and its metabolite GS-441524, samples were collected on the first day of therapy. A nonlinear mixed-effects model was developed to describe the pharmacokinetics and identify potential covariates that explain variability. Alternative dosing regimens were evaluated using Monte Carlo simulations. Seventeen patients were included. Remdesivir and GS-441524 pharmacokinetics were best described by a one-compartment model. The estimated glomerular filtration rate (eGFR) on GS-441524 clearance was identified as a clinically relevant covariate. The interindividual variability in clearance and volume of distribution for both remdesivir and GS-441524 was high (remdesivir, 38.9% and 47.9%, respectively; GS-441525, 47.4% and 42.9%, respectively). The estimated elimination half-life for remdesivir was 0.48 h, and that for GS-441524 was 26.6 h. The probability of target attainment (PTA) of the in vitro 50% effective concentration (EC₅₀) for GS-441524 in plasma can be improved by shortening the dose interval of remdesivir and thereby increasing the total daily dose (PTA, 51.4% versus 94.7%). In patients with reduced renal function, the metabolite GS-441524 accumulates. A population pharmacokinetic model for remdesivir and GS-441524 in COVID-19 patients was developed. Remdesivir showed highly variable pharmacokinetics. The elimination half-life of remdesivir in COVID-19 patients is short, and the clearance of GS-441524 is dependent on the eGFR. Alternative dosing regimens aimed at optimizing the remdesivir and GS-441524 concentrations may improve the effectiveness of remdesivir treatment in COVID-19 patients.

Remdesivir for COVID‐19 pneumonia in patients with severe chronic kidney disease: A Case series and review of the literature

Remdesivir was the first antiviral agent to receive FDA authorization for severe COVID‐19 management, which restricts its use with severe renal impairment due to concerns that active metabolites might accumulate, causing renal toxicities. With limited treatment options, available evidence on such patient groups is important to assess for future safety.

Our report suggests that Remdesivir is well tolerated and potentially safe among hospitalized patients with severe COVID‐19 infection with the background of advanced kidney diseases where benefits outweigh potential risks.

Population pharmacokinetic modeling of GS-441524, the active metabolite of remdesivir, in Japanese COVID-19 patients with renal dysfunction

Remdesivir, a prodrug of the nucleoside analog GS‐441524, plays a key role in the treatment of coronavirus disease 2019 (COVID‐19). However, owing to limited information on clinical trials and inexperienced clinical use, there is a lack of pharmacokinetic (PK) data in patients with COVID‐19 with special characteristics. In this study, we aimed to measure serum GS‐441524 concentrations and develop a population PK (PopPK) model. Remdesivir was administered at a 200 mg loading dose on the first day followed by 100 mg from day 2, based on the package insert, in patients with an estimated glomerular filtration rate (eGFR) greater than or equal to 30 ml/min. In total, 190 concentrations from 37 Japanese patients were used in the analysis. The GS‐441524 trough concentrations were significantly higher in the eGFR less than 60 ml/min group than in the eGFR greater than or equal to 60 ml/min group. Extracorporeal membrane oxygenation in four patients hardly affected the total body clearance (CL) and volume of distribution (V_d) of GS‐441524. A one‐compartment model described serum GS‐441524 concentration data. The CL and V_d of GS‐441524 were significantly affected by eGFR readjusted by individual body surface area and age, respectively. Simulations proposed a dose regimen of 200 mg on day 1 followed by 100 mg once every 2 days from day 2 in patients with an eGFR of 30 ml/min or less. In conclusion, we successfully established a PopPK model of GS‐441524 using retrospectively obtained serum GS‐441524 concentrations in Japanese patients with COVID‐19, which would be helpful for optimal individualized therapy of remdesivir.