Oral administration of obeldesivir protects nonhuman primates against Sudan ebolavirus.

Obeldesivir (ODV, GS-5245) is an orally administered prodrug of the parent nucleoside of remdesivir (RDV) and is presently in phase 3 trials for COVID-19 treatment. In this work, we show that ODV and its circulating parent nucleoside metabolite, GS-441524, have similar in vitro antiviral activity against filoviruses, including Marburg virus, Ebola virus, and Sudan virus (SUDV). We also report that once-daily oral ODV treatment of cynomolgus monkeys for 10 days beginning 24 hours after SUDV exposure confers 100% protection against lethal infection. Transcriptomics data show that ODV treatment delayed the onset of inflammation and correlated with antigen presentation and lymphocyte activation. Our results offer promise for the further development of ODV to control outbreaks of filovirus disease more rapidly.

Comparison of Outcomes in Patients Requiring Mechanical Circulatory Support Who Received Cangrelor in Addition to Anticoagulation Versus Anticoagulation Alone.

OBJECTIVES: To evaluate the safety of cangrelor administered concurrently with heparin or bivalirudin in patients on mechanical circulatory support. DESIGN: A single-center, retrospective cohort study of adult patients consecutively admitted between January 2016 and October 2020. SETTING: A tertiary medical center. PARTICIPANTS: Adult patients admitted to the cardiovascular intensive care unit put on mechanical circulatory support for acute myocardial infarction (AMI) or non-AMI indications. Patients who received cangrelor underwent percutaneous coronary intervention with stenting during the index event or within the last year. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the incidence of major bleeding, defined by the Extracorporeal Life Support Organization criteria, in patients with mechanical circulatory support receiving cangrelor plus anticoagulation with heparin or bivalirudin with or without aspirin versus patients who did not receive cangrelor. Sixty-eight patients were included in the study. Twenty-nine patients received cangrelor, and 39 did not. Cangrelor was not associated with an increase in major bleeding; however, the CI was wide (adjusted hazard ratio 1.93, 95% CI 0.61-6.11; p = 0.262). CONCLUSIONS: Patients receiving cangrelor did not appear to be at higher risk of major bleeding compared to patients not receiving cangrelor. Larger trials should be conducted to better evaluate the safety of cangrelor in patients with mechanical circulatory support.

Functional properties of measles virus proteins derived from a subacute sclerosing panencephalitis patient who received repeated remdesivir treatments.

Subacute sclerosing panencephalitis (SSPE) is a rare but fatal late neurological complication of measles, caused by persistent measles virus (MeV) infection of the central nervous system. There are no drugs approved for the treatment of SSPE. Here, we followed the clinical progression of a 5-year-old SSPE patient after treatment with the nucleoside analog remdesivir, conducted a post-mortem evaluation of the patient's brain, and characterized the MeV detected in the brain. The quality of life of the patient transiently improved after the first two courses of remdesivir, but a third course had no further clinical effect, and the patient eventually succumbed to his condition. Post-mortem evaluation of the brain displayed histopathological changes including loss of neurons and demyelination paired with abundant presence of MeV RNA-positive cells throughout the brain. Next-generation sequencing of RNA isolated from the brain revealed a complete MeV genome with mutations that are typically detected in SSPE, characterized by a hypermutated M gene. Additional mutations were detected in the polymerase (L) gene, which were not associated with resistance to remdesivir. Functional characterization showed that mutations in the F gene led to a hyperfusogenic phenotype predominantly mediated by N465I. Additionally, recombinant wild-type-based MeV with the SSPE-F gene or the F gene with the N465I mutation was no longer lymphotropic but instead efficiently disseminated in neural cultures. Altogether, this case encourages further investigation of remdesivir as a potential treatment of SSPE and highlights the necessity to functionally understand SSPE-causing MeV.IMPORTANCEMeasles virus (MeV) causes acute, systemic disease and remains an important cause of morbidity and mortality in humans. Despite the lack of known entry receptors in the brain, MeV can persistently infect the brain causing the rare but fatal neurological disorder subacute sclerosing panencephalitis (SSPE). SSPE-causing MeVs are characterized by a hypermutated genome and a hyperfusogenic F protein that facilitates the rapid spread of MeV throughout the brain. No treatment against SSPE is available, but the nucleoside analog remdesivir was recently demonstrated to be effective against MeV in vitro. We show that treatment of an SSPE patient with remdesivir led to transient clinical improvement and did not induce viral escape mutants, encouraging the future use of remdesivir in SSPE patients. Functional characterization of the viral proteins sheds light on the shared properties of SSPE-causing MeVs and further contributes to understanding how those viruses cause disease.

Remdesivir plus dexamethasone is associated to improvement in the clinical outcome of COVID-19 hospitalized patients regardless of their vaccination status / Remdesivir más dexametasona se asocian a una reducción de los eventos clínicos en los pacientes hospitalizados por COVID-19, independientemente de su estado de vacunación

Introduction Remdesivir seems to reduce the risk of hospitalization and improve clinical outcome in hospitalized patients with COVID-19. Objectives To compare the clinical outcome of COVID-19 hospitalized patients treated with remdesivir plus dexamethasone versus dexamethasone alone, according to their vaccination status. Material and methods A retrospective observational study was carried out in 165 patients hospitalized for COVID-19 from October 2021 to January 2022. Multivariate logistic regression, Kaplan–Meier and the log-rank tests were used to evaluate the event (need for ventilation or death). Results Patients treated with remdesivir plus dexamethasone (n=87) compared with dexamethasone alone (n=78) showed similar age (60±16, 47–70 vs. 62±37, 51–74 years) and number of comorbidities: 1 (0–2) versus 1.5 (1–3). Among 73 fully vaccinated patients, 42 (47.1%) were in remdesivir plus dexamethasone and 31 (41%) in dexamethasone alone. Patients treated with remdesivir plus dexamethasone needed intensive care less frequently (17.2% vs. 31%; p=0.002), high-flow oxygen (25.3% vs. 50.0%; p=0.002) and non-invasive mechanical ventilation (16.1% vs. 47.4%; p<0.001). Furthermore, they had less complications during hospitalization (31.0% vs. 52.6%; p=0.008), need of antibiotics (32.2% vs. 59%; p=0.001) and radiologic worsening (21.8% vs. 44.9%; p=0.005). Treatment with remdesivir plus dexamethasone (aHR, 0.26; 95% CI: 0.14–0.48; p<0.001) and vaccination (aHR 0.39; 95% CI: 0.21–0.74) were independent factors associated with lower progression to mechanical ventilation or death. Conclusions Remdesivir in combination with dexamethasone and vaccination independently and synergistically protects hospitalized COVID-19 patients requiring oxygen therapy from progression to severe disease or dead (AU)

Introducción Remdesivir parece reducir el riesgo de hospitalización y mejorar el resultado clínico en pacientes hospitalizados con COVID-19. Objetivos Comparar el desenlace clínico de pacientes hospitalizados con COVID-19 tratados con remdesivir más dexametasona vs. dexametasona sola, según su estado de vacunación. Material y métodos Se realizó un estudio observacional retrospectivo en 165 pacientes hospitalizados por COVID-19 desde octubre de 2021 hasta enero de 2022. Se consideró como evento la necesidad de ventilación o muerte. esultados Los pacientes tratados con remdesivir más dexametasona (n=87) en comparación con dexametasona sola (n=78) mostraron una edad similar (60±16, 47-70 vs. 62±37, 51-74 años) y número de comorbilidades: 1 (0-2) vs. 1,5 (1-3). Entre 73 pacientes completamente vacunados, 42 (47,1%) estaban en remdesivir más dexametasona y 31 (41%) en dexametasona sola. Los pacientes tratados con remdesivir más dexametasona necesitaron cuidados intensivos con menos frecuencia (17,2 vs. 31%; p=0,002), oxígeno de alto flujo (25,3 vs. 50%; p=0,002) y ventilación mecánica no invasiva (16,1 vs. 47,4%, p<0,001). Además, tuvieron menos complicaciones durante la hospitalización (31 vs. 52,6%; p=0,008), necesidad de antibióticos (32,2 vs. 59%; p=0,001) y empeoramiento radiológico (21,8 vs. 44,9%; p=0,005). El tratamiento con remdesivir más dexametasona (aHR, 0,26; IC 95% 0,14-0,48; p<0,001) y la vacunación (aHR 0,39; IC 95% 0,21-0,74>) fueron factores independientes asociados con una menor progresión a ventilación mecánica o muerte. Conclusiones Remdesivir en combinación con dexametasona protegieron de forma independiente y sinérgica a los pacientes hospitalizados con COVID-19 que requieren oxigenoterapia de la progresión a la enfermedad grave o la muerte (AU)

Remdesivir for the treatment of patients in hospital with COVID-19 in Canada: a randomized controlled trial.

BACKGROUND: The role of remdesivir in the treatment of patients in hospital with COVID-19 remains ill defined in a global context. The World Health Organization Solidarity randomized controlled trial (RCT) evaluated remdesivir in patients across many countries, with Canada enrolling patients using an expanded data collection format in the Canadian Treatments for COVID-19 (CATCO) trial. We report on the Canadian findings, with additional demographics, characteristics and clinical outcomes, to explore the potential for differential effects across different health care systems. METHODS: We performed an open-label, pragmatic RCT in Canadian hospitals, in conjunction with the Solidarity trial. We randomized patients to 10 days of remdesivir (200 mg intravenously [IV] on day 0, followed by 100 mg IV daily), plus standard care, or standard care alone. The primary outcome was in-hospital mortality. Secondary outcomes included changes in clinical severity, oxygen- and ventilator-free days (at 28 d), incidence of new oxygen or mechanical ventilation use, duration of hospital stay, and adverse event rates. We performed a priori subgroup analyses according to duration of symptoms before enrolment, age, sex and severity of symptoms on presentation. RESULTS: Across 52 Canadian hospitals, we randomized 1282 patients between Aug. 14, 2020, and Apr. 1, 2021, to remdesivir (n = 634) or standard of care (n = 648). Of these, 15 withdrew consent or were still in hospital, for a total sample of 1267 patients. Among patients assigned to receive remdesivir, in-hospital mortality was 18.7%, compared with 22.6% in the standard-of-care arm (relative risk [RR] 0.83 (95% confidence interval [CI] 0.67 to 1.03), and 60-day mortality was 24.8% and 28.2%, respectively (95% CI 0.72 to 1.07). For patients not mechanically ventilated at baseline, the need for mechanical ventilation was 8.0% in those assigned remdesivir, and 15.0% in those receiving standard of care (RR 0.53, 95% CI 0.38 to 0.75). Mean oxygen-free and ventilator-free days at day 28 were 15.9 (± standard deviation [SD] 10.5) and 21.4 (± SD 11.3) in those receiving remdesivir and 14.2 (± SD 11) and 19.5 (± SD 12.3) in those receiving standard of care (p = 0.006 and 0.007, respectively). There was no difference in safety events of new dialysis, change in creatinine, or new hepatic dysfunction between the 2 groups. INTERPRETATION: Remdesivir, when compared with standard of care, has a modest but significant effect on outcomes important to patients and health systems, such as the need for mechanical ventilation. Trial registration: ClinicalTrials.gov, no. NCT04330690.

Subcutaneous remdesivir administration prevents interstitial pneumonia in rhesus macaques inoculated with SARS-CoV-2.

The utility of remdesivir treatment in COVID-19 patients is currently limited by the necessity to administer this antiviral intravenously, which has generally limited its use to hospitalized patients. Here, we tested a novel, subcutaneous formulation of remdesivir in the rhesus macaque model of SARS-CoV-2 infection that was previously used to establish the efficacy of remdesivir against this virus in vivo. Compared to vehicle-treated animals, macaques treated with subcutaneous remdesivir from 12 h through 6 days post inoculation showed reduced signs of respiratory disease, a reduction of virus replication in the lower respiratory tract, and an absence of interstitial pneumonia. Thus, early subcutaneous administration of remdesivir can protect from lower respiratory tract disease caused by SARS-CoV-2.

Impact of cytokine storm on severity of COVID-19 disease in a private hospital in West Jakarta prior to vaccination.

BACKGROUND AND AIM: Coronavirus Disease 2019 (COVID-19) has become a worldwide pandemic and is a threat to global health. Patients who experienced cytokine storms tend to have a high mortality rate. However, to date, no study has investigated the impact of cytokine storms. MATERIALS AND METHODS: This retrospective cohort study included only COVID-19 positive patients hospitalized in a Private Hospital in West Jakarta between March and September 2020. All patients were not vaccinated during this period and treatment was based on the guidelines by the Ministry of Health Indonesia. A convenience sampling method was used and all patients who met the inclusion criteria were enrolled. RESULTS: The clinical outcome of COVID-19 patients following medical therapy was either cured (85.7%) or died (14.3%), with 14.3% patients reported to have cytokine storm, from which 23.1% led to fatalities. A plasma immunoglobulin (Gammaraas®) and/or tocilizumab (interleukin-6 receptor antagonist; Actemra®) injection was utilised to treat the cytokine storm while remdesivir and oseltamivir were administered to ameliorate COVID-19. Most (61.5%) patients who experienced the cytokine storm were male; mean age 60 years. Interestingly, all patients who experienced the cytokine storm had hypertension or/ and diabetes complication (100%). Fever, cough and shortness of breath were also the common symptoms (100.0%). Almost all (92.3%) patients with cytokine storm had to be treated in the intensive care unit (ICU). Most (76.9%) patients who had cytokine storm received hydroxychloroquine and all had antibiotics [1) azithromycin + levofloxacin or 2) meropenam for critically ill patients] and vitamins such as vitamins C and B-complex as well as mineral. Unfortunately, from this group, 23.1% patients died while the remaining 70% of patients recovered. A significant (p<0.05) correlation was established between cytokine storms and age, the presence of comorbidity, diabetes, hypertension, fever, shortness of breath, having oxygen saturation (SPO2) less than 93%, cold, fatigue, ward of admission, the severity of COVID-19 disease, duration of treatment as well as the use of remdesivir, Actemra® and Gammaraas®. Most patients recovered after receiving a combination treatment (oseltamivir + remdesivir + Antibiotics + Vitamin/Mineral) for approximately 11 days with a 90% survival rate. On the contrary, patients who received oseltamivir + hydroxychloroquine + Gammaraas® + antibiotics +Vitamin/Mineral, had a 83% survival rate after being admitted to the hospital for about ten days. CONCLUSION: Factors influencing the development of a cytokine storm include age, duration of treatment, comorbidity, symptoms, type of admission ward and severity of infection. Most patients (76.92%) with cytokine storm who received Gammaraas®/Actemra®, survived although they were in the severe and critical levels (87.17%). Overall, based on the treatment duration and survival rate, the most effective therapy was a combination of oseltamivir + favipiravir + hydroxychloroquine + antibiotics + vitamins/minerals.

The therapeutic efficacy of quercetin in combination with antiviral drugs in hospitalized COVID-19 patients: A randomized controlled trial.

In this study, the therapeutic efficacy of quercetin in combination with remdesivir and favipiravir, were evaluated in severe hospitalized COVID-19 patients. Our main objective was to assess the ability of quercetin for preventing the progression of the disease into critical phase, and reducing the levels of inflammatory markers related to SARS-Cov-2 pathogenesis. Through an open-label clinical trial, 60 severe cases were randomly divided into control and intervention groups. During a 7-day period, patients in the control group received antivirals, i.e., remdesivir or favipiravir, while the intervention group was treated with 1000 mg of quercetin daily in addition to the antiviral drugs. According to the results, taking quercetin was significantly associated with partial earlier discharge and reduced serum levels of ALP, q-CRP, and LDH in the intervention group. Furthermore, although the values were in normal range, the statistical outputs showed significant increase in hemoglobin level and respiratory rate in patients who were taking quercetin. Based on our observations, quercetin is safe and effective in lowering the serum levels of ALP, q-CRP, and LDH as critical markers involved in COVID-19 severity. However, according to the non-significant borderline results in comparing the mortality, the ICU-admission rate, and the duration of ICU-admission, further studies can be helpful to compensate the limitations of our study and clarify the therapeutic potential of quercetin in COVID-19 treatments.

Association and pharmacological synergism of the triple drug therapy baricitinib/remdesivir/rhACE2 for the management of COVID-19 infection.

A massive vaccination campaign against the global COVID-19 pandemic caused by SARS-CoV-2 virus began worldwide in January 2021. However, studies continue to investigate the most effective and safe drug therapies to manage the various stages of viral infection. It is critical in the therapeutic management of the patient, with ongoing COVID-19 infection, to reduce viral load and replication, and to regulate the generalized hyperinflammatory state caused by the cytokine storm that occurs in the most severe phases. Probably the right drug therapy is represented by the use of different drugs acting in different modalities and on different targets, to avoid also viral drug resistance. In this article, we describe an interesting scientific pharmacological hypothesis arising from the evidence in the literature; we believe that the association of baricitinib/remdesivir/rhACE2, administered at the right time and dose, represents an important pharmacological synergism that can be therapeutically more effective for the treatment of COVID-19 infection than the single administration of drugs and avoid the phenomenon of drug resistance caused by the virus.

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.

Randomized, double-blind, controlled trial of human anti-LIGHT monoclonal antibody in COVID-19 acute respiratory distress syndrome.

BACKGROUNDSevere coronavirus disease 2019 (COVID-19) is associated with a dysregulated immune response, which can result in cytokine-release syndrome and acute respiratory distress syndrome (ARDS). Patients with COVID-19-associated ARDS have elevated free serum levels of the cytokine lymphotoxin-like inducible protein that competes with glycoprotein D for herpesvirus entry on T cells (LIGHT; also known as TNFSF14). Such patients may benefit from LIGHT-neutralization therapy.METHODSThis randomized, double-blind, multicenter, proof-of-concept trial enrolled adults hospitalized with COVID-19-associated pneumonia and mild to moderate ARDS. Patients received standard of care plus a single dose of a human LIGHT-neutralizing antibody (CERC-002) or placebo. The primary endpoint was the proportion of patients receiving CERC-002 who remained alive and free of respiratory failure through day 28. Safety was assessed via adverse event monitoring.RESULTSFor most of the 83 enrolled patients, standard of care included systemic corticosteroids (88.0%) or remdesivir (57.8%). A higher proportion of patients remained alive and free of respiratory failure through day 28 after receiving CERC-002 (83.9%) versus placebo (64.5%; P = 0.044), including in patients 60 years of age or older (76.5% vs. 47.1%, respectively; P = 0.042). Mortality rates were 7.7% (CERC-002) and 14.3% (placebo) on day 28 and 10.8% and 22.5%, respectively, on day 60. Treatment-emergent adverse events were less frequent with CERC-002 than placebo.CONCLUSIONFor patients with COVID-19-associated ARDS, adding CERC-002 to standard-of-care treatment reduces LIGHT levels and might reduce the risk of respiratory failure and death.TRIAL REGISTRATIONClinicalTrials.gov NCT04412057.FUNDINGAvalo Therapeutics.

Safety of Intravenous Cangrelor Administration for Antiplatelet Bridging in Hospitalized Patients: A Retrospective Study.

OBJECTIVE: We aimed to characterize outcomes associated with cangrelor administration used in an antiplatelet bridging strategy in real-world clinical scenarios within a large academic medical system. BACKGROUND: Cangrelor has been used for antiplatelet bridging in perioperative settings or for patients unable to take oral medications. Prior studies in these settings have reported bleeding rates from 0%-40%. METHODS: Patients were retrospectively identified via chart review and included if they were over 18 years old, had coronary or peripheral arterial stents, and had received at least 1 hour of cangrelor infusion during inpatient admission. The primary endpoint was Bleeding Academic Research Consortium (BARC) 3-5 bleeding during cangrelor infusion or within 48 hours of discontinuation; secondary endpoints were bleeding events defined by Thrombolysis in Myocardial Infarction (TIMI), Global Use of Strategies to Open Occluded Arteries (GUSTO), and International Society on Thrombosis and Hemostasis (ISTH) criteria, as well as BARC 2 bleeding. RESULTS: Thirty-one patients met the inclusion criteria. Cangrelor indications were bridging to procedure in 22 patients (71.0%) and inability to take oral P2Y12 inhibitors in 9 patients (29.0%). Twenty-three patients (74.2%) were men, 11 patients (35.5%) were in cardiogenic shock, and 4 patients (12.9%) were on extracorporeal membrane oxygenation (ECMO) at the time of administration. No patients received cangrelor for routine percutaneous coronary intervention. Of the 31 patients, 13 (41.9%) had BARC 3-5 bleeding and 7 (22.6%) expired during hospitalization. All 4 patients on ECMO suffered BARC 3-5 bleeding. CONCLUSIONS: We reviewed the use of cangrelor for antiplatelet bridging in real-world clinical scenarios and observed higher rates of clinically significant bleeding than seen in other similar studies. Our study suggests careful consideration when using cangrelor in a sick patient population.

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.

Remdesivir: Quo vadis?

Remdesivir (GS-5734, Veklury®) has remained the only antiviral drug formally approved by the US FDA for the treatment of Covid-19 (SARS-CoV-2 infection). Its key structural features are the fact that it is a C-nucleoside (adenosine) analogue, contains a 1'-cyano function, and could be considered as a ProTide based on the presence of a phosphoramidate group. Its antiviral spectrum and activity in animal models have been well established and so has been its molecular mode of action as a delayed chain terminator of the viral RdRp (RNA-dependent RNA polymerase). Its clinical efficacy has been evaluated, but needs to be optimized with regard to timing, dosage and duration of treatment, and route of administration. Safety, toxicity and pharmacokinetics need to be further addressed, and so are its potential combinations with other drugs such as corticosteroids (i.e. dexamethasone) and ribavirin.

Preclinical characterization of an intravenous coronavirus 3CL protease inhibitor for the potential treatment of COVID19.

COVID-19 caused by the SARS-CoV-2 virus has become a global pandemic. 3CL protease is a virally encoded protein that is essential across a broad spectrum of coronaviruses with no close human analogs. PF-00835231, a 3CL protease inhibitor, has exhibited potent in vitro antiviral activity against SARS-CoV-2 as a single agent. Here we report, the design and characterization of a phosphate prodrug PF-07304814 to enable the delivery and projected sustained systemic exposure in human of PF-00835231 to inhibit coronavirus family 3CL protease activity with selectivity over human host protease targets. Furthermore, we show that PF-00835231 has additive/synergistic activity in combination with remdesivir. We present the ADME, safety, in vitro, and in vivo antiviral activity data that supports the clinical evaluation of PF-07304814 as a potential COVID-19 treatment.