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 (Vd ) of GS-441524. A one-compartment model described serum GS-441524 concentration data. The CL and Vd 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.

Transparency, health equity, and strategies in state-based protocols for remdesivir allocation and use.

BACKGROUND: The Emergency Use Authorization (EUA) of remdesivir for coronavirus disease 2019 raised questions on transparency of applied strategy, and how to equitably allocate and prioritize eligible patients given limited supply of the medication. The absence of federal oversight highlighted the critical role by states in health policymaking during a pandemic. OBJECTIVE: To identify public state-based protocols for remdesivir allocation and clinical guidance for prioritizing remdesivir use and assess approaches and inclusion of language promoting equitable access or mitigating health disparities. METHODS: We identified remdesivir allocation strategies and clinical use guidelines for all 50 states in the U.S. and the District of Columbia accessible on state health department websites or via internet searches. Public protocols dated between May 1, 2020 and September 30, 2020 were included in the study. We reviewed strategies for allocation and clinical use, including whether protocols contained explicit language on equitable access to remdesivir or mitigating health disparities. RESULTS: A total of 38 states had a remdesivir allocation strategy, with 33 states (87%) making these public. States used diverse allocation strategies, and only 10 (30%) of the 33 states included language on equitable allocation. A total of 30 states had remdesivir clinical use guidelines, where all were publicly accessible. All guidelines referenced recommendations by federal agencies but varied in their presentation format. Of the 30 states, 12 (40%) had guidelines that included language on equitable use. Neither an allocation strategy or clinical use guideline were identified (public or non-public) for 10 states and the District of Columbia during the study period. CONCLUSIONS: The experience with the remdesivir EUA presents an opportunity for federal and state governments to develop transparent protocols promoting fair and equal access to treatments for future pandemics.

Assessment of adverse events associated with remdesivir use for coronavirus disease 2019 using real-world data.

Background: Remdesivir has been used for treating patients with moderate to severe coronavirus disease 2019 (COVID-19) although there is conflicting evidence regarding its usefulness. Data regarding its safety largely come from the clinical trials conducted to support its emergency use authorization (EUA). This study aimed to identify the adverse events of remdesivir with disproportionately high reporting using real-world data.Research design and methods: The adverse event reports submitted to the United States Food and Drug Administration Adverse Event Reporting System (FAERS) by health-care professionals for drugs that have received EUA or approved for the treatment of COVID-19 in the US were studied. Adisproportionality analysis was performed to determine adverse events more frequently reported with remdesivir compared with other COVID-19 drugs in the database.Results: Elevated liver enzymes, acute kidney injury, raised blood creatinine levels, bradycardia, cardiac arrest, and death had disproportionately higher reporting with remdesivir as asuspect drug compared with other drugs. There is no significant difference in the reporting of these events based on patient sex or age.Conclusions: Our study confirms the drug label information regarding liver enzyme elevation. The renal and cardiac safety signals identified necessitate reevaluation for potential drug-labeling changes.

Were it business opportunities or hidden risks: Observations on clinical trials and marketing authorizations of Gilead Science's remdesivir in China.

New drugs against the in COVID-19 pandemic are urgently needed. Gilead Science's remdesivir has been introduced to China through special approval procedures, and was directly conducting the Phase III clinical trial. As expected, the marketing authorization process was completed soon. The drug brought hope to patients as well as business opportunities to companies. However, we must pay attention to the patent competition, generic drug competition and other unfair competition that remdesivir may face in China. China also needs to strengthen the innovation ability and international cooperation ability of local pharmaceutical companies by taking advantages of the opportunity to introduce remdesivir.

Simulated Assessment of Pharmacokinetically Guided Dosing for Investigational Treatments of Pediatric Patients With Coronavirus Disease 2019.

Importance: Children of all ages appear susceptible to severe acute respiratory syndrome coronavirus 2 infection. To support pediatric clinical studies for investigational treatments of coronavirus disease 2019 (COVID-19), pediatric-specific dosing is required. Objective: To define pediatric-specific dosing regimens for hydroxychloroquine and remdesivir for COVID-19 treatment. Design, Setting, and Participants: Pharmacokinetic modeling and simulation were used to extrapolate investigated adult dosages toward children (March 2020-April 2020). Physiologically based pharmacokinetic modeling was used to inform pediatric dosing for hydroxychloroquine. For remdesivir, pediatric dosages were derived using allometric-scaling with age-dependent exponents. Dosing simulations were conducted using simulated pediatric and adult participants based on the demographics of a white US population. Interventions: Simulated drug exposures following a 5-day course of hydroxychloroquine (400 mg every 12 hours × 2 doses followed by 200 mg every 12 hours × 8 doses) and a single 200-mg intravenous dose of remdesivir were computed for simulated adult participants. A simulation-based dose-ranging study was conducted in simulated children exploring different absolute and weight-normalized dosing strategies. Main Outcomes and Measures: The primary outcome for hydroxychloroquine was average unbound plasma concentrations for 5 treatment days. Additionally, unbound interstitial lung concentrations were simulated. For remdesivir, the primary outcome was plasma exposure (area under the curve, 0 to infinity) following single-dose administration. Results: For hydroxychloroquine, the physiologically based pharmacokinetic model analysis included 500 and 600 simulated white adult and pediatric participants, respectively, and supported weight-normalized dosing for children weighing less than 50 kg. Geometric mean-simulated average unbound plasma concentration values among children within different developmental age groups (32-35 ng/mL) were congruent to adults (32 ng/mL). Simulated unbound hydroxychloroquine concentrations in lung interstitial fluid mirrored those in unbound plasma and were notably lower than in vitro concentrations needed to mediate antiviral activity. For remdesivir, the analysis included 1000 and 6000 simulated adult and pediatric participants, respectively. The proposed pediatric dosing strategy supported weight-normalized dosing for participants weighing less than 60 kg. Geometric mean-simulated plasma area under the time curve 0 to infinity values among children within different developmental age-groups (4315-5027 ng × h/mL) were similar to adults (4398 ng × h/mL). Conclusions and Relevance: This analysis provides pediatric-specific dosing suggestions for hydroxychloroquine and remdesivir and raises concerns regarding hydroxychloroquine use for COVID-19 treatment because concentrations were less than those needed to mediate an antiviral effect.

Incidence, Predictors, and Outcomes of Acquired Thrombocytopenia After Percutaneous Coronary Intervention: A Pooled, Patient-Level Analysis of the CHAMPION Trials (Cangrelor Versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition).

BACKGROUND: The influence of cangrelor on the incidence and outcomes of post-percutaneous coronary intervention (PCI) thrombocytopenia is not defined. We aimed to explore the incidence, predictors, and clinical impact of thrombocytopenia after PCI in cangrelor-treated patients. METHODS AND RESULTS: This was a pooled, patient-level analysis of the CHAMPION trials (Cangrelor Versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition), which compared cangrelor with clopidogrel for prevention of thrombotic complications during and after PCI. Acquired thrombocytopenia was defined as either a drop in platelet count to <100 000 after PCI or a drop of >50% between baseline and a follow-up. The main efficacy outcome was major adverse cardiac events. The primary safety outcome was noncoronary artery bypass grafting-related Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries-defined severe bleeding at 48 hours. Patients (23 783) were enrolled, and 3009 (12.7%) received a GPI (glycoprotein IIb/IIIa inhibitor). Acquired thrombocytopenia occurred in 200 patients (0.8%). The adjusted rate of major adverse cardiovascular events at 48 hours was significantly higher in patients who developed thrombocytopenia compared with those who did not (odds ratio, 3.00; 95% confidence interval, 1.89-4.69; P<0.001), as was major bleeding (odds ratio, 14.71; 95% confidence interval, 5.96-36.30; P<0.001). GPI use was the strongest independent predictor of acquired thrombocytopenia (odds ratio, 2.93; 95% confidence interval, 2.15-3.97; P<0.0001). There was no difference in the rate of acquired thrombocytopenia in patients randomized to cangrelor or clopidogrel. CONCLUSIONS: Acquired thrombocytopenia after PCI is strongly associated with substantial early morbidity and mortality, as well as major bleeding. GPI use is a significant predictor of thrombocytopenia. Cangrelor is not associated with acquired thrombocytopenia, and its clinical efficacy and safety is consistent irrespective of thrombocytopenia occurrence. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifiers: NCT00305162, NCT00385138, and NCT01156571.

Adenosine monophosphate is not superior to histamine for bronchial provocation test for assessment of asthma control and symptoms.

BACKGROUND: Adenosine monophosphate (AMP) may reflect airway inflammation and hyperresponsiveness, but relationship between AMP and histamine (His, a conventional stimulus) bronchial provocation test (BPT) in asthma is not fully elucidated. OBJECTIVES: To compare both BPTs and determine their utility in reflecting changes of asthmatic symptoms. METHODS: BPTs were performed in a cross-over fashion, at 2-4 day intervals. Cumulative doses eliciting 20% FEV1 fall (PD20 FEV1 ), diagnostic performance and adverse events (AEs) were compared. Patients with PD20 FEV1 lower than geometric mean were defined as responders, otherwise poor responders. Patients with uncontrolled and partly controlled asthma, who maintained their original inhaled corticosteroids therapy, underwent reassessment of airway responsiveness and asthmatic symptoms 3 and 6 months after. RESULTS: Nineteen uncontrolled, 22 partly controlled and 19 controlled asthmatic patients and 24 healthy subjects were recruited. Lower PD20 FEV1 geometric means were associated with poorer asthma control in His-BPT (0.424 µmol vs 1.684 µmol vs 3.757 µmol), but not AMP-BPT (11.810 µmol vs 7.781 µmol vs 10.220 µmol). Both BPTs yielded similar overall diagnostic performance in asthma (area under curve: 0.842 in AMP-BPT vs 0.850 in His-BPT). AEs, including wheezing and tachypnea, were similar and mild. Ten patients with uncontrolled and 10 partly controlled asthma were followed-up. At months 3 and 6, we documented an increase in PD20 FEV1 -AMP and PD20 FEV1 -His, which did not correlate with reduction asthmatic symptom scores. This overall applied in responders and poor responders of AMP-BPT and His-BPT. CONCLUSION: Despite higher screening capacity of well-controlled asthma, AMP-BPT confers similar diagnostic performance and safety with His-BPT. AMP-BPT might not preferentially reflect changes asthmatic symptoms.