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Nat Commun ; 13(1): 719, 2022 02 15.
Article in English | MEDLINE | ID: covidwho-1692616


There is an urgent need for potent and selective antivirals against SARS-CoV-2. Pfizer developed PF-07321332 (PF-332), a potent inhibitor of the viral main protease (Mpro, 3CLpro) that can be dosed orally and that is in clinical development. We here report that PF-332 exerts equipotent in vitro activity against the four SARS-CoV-2 variants of concerns (VoC) and that it can completely arrest replication of the alpha variant in primary human airway epithelial cells grown at the air-liquid interface. Treatment of Syrian Golden hamsters with PF-332 (250 mg/kg, twice daily) completely protected the animals against intranasal infection with the beta (B.1.351) and delta (B.1.617.2) SARS-CoV-2 variants. Moreover, treatment of SARS-CoV-2 (B.1.617.2) infected animals with PF-332 completely prevented transmission to untreated co-housed sentinels.

COVID-19 Drug Treatment , Disease Models, Animal , Lactams/administration & dosage , Leucine/administration & dosage , Nitriles/administration & dosage , Proline/administration & dosage , SARS-CoV-2/drug effects , Viral Protease Inhibitors/administration & dosage , A549 Cells , Administration, Oral , Animals , COVID-19/prevention & control , COVID-19/transmission , COVID-19/virology , Chlorocebus aethiops , Coronavirus 3C Proteases/antagonists & inhibitors , Cricetinae , Humans , Lactams/pharmacokinetics , Leucine/pharmacokinetics , Mesocricetus , Nitriles/pharmacokinetics , Proline/pharmacokinetics , Respiratory Mucosa/drug effects , Respiratory Mucosa/virology , SARS-CoV-2/enzymology , SARS-CoV-2/physiology , Vero Cells , Viral Protease Inhibitors/pharmacokinetics , Virus Replication/drug effects
N Engl J Med ; 386(15): 1397-1408, 2022 04 14.
Article in English | MEDLINE | ID: covidwho-1692474


BACKGROUND: Nirmatrelvir is an orally administered severe acute respiratory syndrome coronavirus 2 main protease (Mpro) inhibitor with potent pan-human-coronavirus activity in vitro. METHODS: We conducted a phase 2-3 double-blind, randomized, controlled trial in which symptomatic, unvaccinated, nonhospitalized adults at high risk for progression to severe coronavirus disease 2019 (Covid-19) were assigned in a 1:1 ratio to receive either 300 mg of nirmatrelvir plus 100 mg of ritonavir (a pharmacokinetic enhancer) or placebo every 12 hours for 5 days. Covid-19-related hospitalization or death from any cause through day 28, viral load, and safety were evaluated. RESULTS: A total of 2246 patients underwent randomization; 1120 patients received nirmatrelvir plus ritonavir (nirmatrelvir group) and 1126 received placebo (placebo group). In the planned interim analysis of patients treated within 3 days after symptom onset (modified intention-to treat population, comprising 774 of the 1361 patients in the full analysis population), the incidence of Covid-19-related hospitalization or death by day 28 was lower in the nirmatrelvir group than in the placebo group by 6.32 percentage points (95% confidence interval [CI], -9.04 to -3.59; P<0.001; relative risk reduction, 89.1%); the incidence was 0.77% (3 of 389 patients) in the nirmatrelvir group, with 0 deaths, as compared with 7.01% (27 of 385 patients) in the placebo group, with 7 deaths. Efficacy was maintained in the final analysis involving the 1379 patients in the modified intention-to-treat population, with a difference of -5.81 percentage points (95% CI, -7.78 to -3.84; P<0.001; relative risk reduction, 88.9%). All 13 deaths occurred in the placebo group. The viral load was lower with nirmatrelvir plus ritonavir than with placebo at day 5 of treatment, with an adjusted mean difference of -0.868 log10 copies per milliliter when treatment was initiated within 3 days after the onset of symptoms. The incidence of adverse events that emerged during the treatment period was similar in the two groups (any adverse event, 22.6% with nirmatrelvir plus ritonavir vs. 23.9% with placebo; serious adverse events, 1.6% vs. 6.6%; and adverse events leading to discontinuation of the drugs or placebo, 2.1% vs. 4.2%). Dysgeusia (5.6% vs. 0.3%) and diarrhea (3.1% vs. 1.6%) occurred more frequently with nirmatrelvir plus ritonavir than with placebo. CONCLUSIONS: Treatment of symptomatic Covid-19 with nirmatrelvir plus ritonavir resulted in a risk of progression to severe Covid-19 that was 89% lower than the risk with placebo, without evident safety concerns. (Supported by Pfizer; number, NCT04960202.).

Antiviral Agents , COVID-19 Drug Treatment , Lactams , Leucine , Nitriles , Proline , Ritonavir , Administration, Oral , Adult , Antiviral Agents/administration & dosage , Antiviral Agents/adverse effects , Antiviral Agents/therapeutic use , Disease Progression , Double-Blind Method , Hospitalization , Humans , Lactams/administration & dosage , Lactams/adverse effects , Lactams/therapeutic use , Leucine/administration & dosage , Leucine/adverse effects , Leucine/therapeutic use , Nitriles/administration & dosage , Nitriles/adverse effects , Nitriles/therapeutic use , Proline/administration & dosage , Proline/adverse effects , Proline/therapeutic use , Ritonavir/administration & dosage , Ritonavir/adverse effects , Ritonavir/therapeutic use , SARS-CoV-2 , Treatment Outcome , Vaccination , Viral Load/drug effects , Viral Protease Inhibitors/administration & dosage , Viral Protease Inhibitors/adverse effects , Viral Protease Inhibitors/therapeutic use
Science ; 374(6575): 1586-1593, 2021 Dec 24.
Article in English | MEDLINE | ID: covidwho-1666355


The worldwide outbreak of COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic. Alongside vaccines, antiviral therapeutics are an important part of the healthcare response to countering the ongoing threat presented by COVID-19. Here, we report the discovery and characterization of PF-07321332, an orally bioavailable SARS-CoV-2 main protease inhibitor with in vitro pan-human coronavirus antiviral activity and excellent off-target selectivity and in vivo safety profiles. PF-07321332 has demonstrated oral activity in a mouse-adapted SARS-CoV-2 model and has achieved oral plasma concentrations exceeding the in vitro antiviral cell potency in a phase 1 clinical trial in healthy human participants.

COVID-19 Drug Treatment , Lactams/pharmacology , Lactams/therapeutic use , Leucine/pharmacology , Leucine/therapeutic use , Nitriles/pharmacology , Nitriles/therapeutic use , Proline/pharmacology , Proline/therapeutic use , SARS-CoV-2/drug effects , Viral Protease Inhibitors/pharmacology , Viral Protease Inhibitors/therapeutic use , Administration, Oral , Animals , COVID-19/virology , Clinical Trials, Phase I as Topic , Coronavirus/drug effects , Disease Models, Animal , Drug Therapy, Combination , Humans , Lactams/administration & dosage , Lactams/pharmacokinetics , Leucine/administration & dosage , Leucine/pharmacokinetics , Mice , Mice, Inbred BALB C , Microbial Sensitivity Tests , Nitriles/administration & dosage , Nitriles/pharmacokinetics , Proline/administration & dosage , Proline/pharmacokinetics , Randomized Controlled Trials as Topic , Ritonavir/administration & dosage , Ritonavir/therapeutic use , SARS-CoV-2/physiology , Viral Protease Inhibitors/administration & dosage , Viral Protease Inhibitors/pharmacokinetics , Virus Replication/drug effects
Nature ; 601(7894): 496, 2022 01.
Article in English | MEDLINE | ID: covidwho-1641925

Antiviral Agents/therapeutic use , COVID-19 Drug Treatment , COVID-19/virology , Drug Development/trends , Drug Resistance, Viral , Research Personnel , SARS-CoV-2/drug effects , Adenosine Monophosphate/administration & dosage , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/pharmacology , Adenosine Monophosphate/therapeutic use , Administration, Oral , Alanine/administration & dosage , Alanine/analogs & derivatives , Alanine/pharmacology , Alanine/therapeutic use , Antiviral Agents/administration & dosage , Antiviral Agents/pharmacology , Antiviral Agents/supply & distribution , COVID-19/mortality , COVID-19/prevention & control , COVID-19 Vaccines/supply & distribution , Cytidine/administration & dosage , Cytidine/analogs & derivatives , Cytidine/pharmacology , Cytidine/therapeutic use , Drug Approval , Drug Combinations , Drug Resistance, Viral/drug effects , Drug Resistance, Viral/genetics , Drug Therapy, Combination , Hospitalization/statistics & numerical data , Humans , Hydroxylamines/administration & dosage , Hydroxylamines/pharmacology , Hydroxylamines/therapeutic use , Lactams/administration & dosage , Lactams/pharmacology , Lactams/therapeutic use , Leucine/administration & dosage , Leucine/pharmacology , Leucine/therapeutic use , Medication Adherence , Molecular Targeted Therapy , Mutagenesis , Nitriles/administration & dosage , Nitriles/pharmacology , Nitriles/therapeutic use , Proline/administration & dosage , Proline/pharmacology , Proline/therapeutic use , Public-Private Sector Partnerships/economics , Ritonavir/administration & dosage , Ritonavir/pharmacology , Ritonavir/therapeutic use , SARS-CoV-2/enzymology , SARS-CoV-2/genetics
Int Immunopharmacol ; 103: 108463, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1587490


Therapeutics that impair the innate immune responses of the liver during the inflammatory cytokine storm like that occurring in COVID-19 are greatly needed. Much interest is currently directed toward Janus kinase (JAK) inhibitors as potential candidates to mitigate this life-threatening complication. Accordingly, this study investigated the influence of the novel JAK inhibitor ruxolitinib (RXB) on concanavalin A (Con A)-induced hepatitis and systemic hyperinflammation in mice to simulate the context occurring in COVID-19 patients. Mice were orally treated with RXB (75 and 150 mg/kg) 2 h prior to the intravenous administration of Con A (20 mg/kg) for a period of 12 h. The results showed that RXB pretreatments were efficient in abrogating Con A-instigated hepatocellular injury (ALT, AST, LDH), necrosis (histopathology), apoptosis (cleaved caspase-3) and nuclear proliferation due to damage (PCNA). The protective mechanism of RXB were attributed to i) prevention of Con A-enhanced hepatic production and systemic release of the proinflammatory cytokines TNF-α, IFN-γ and IL-17A, which coincided with decreasing infiltration of immune cells (monocytes, neutrophils), ii) reducing Con A-induced hepatic overexpression of IL-1ß and CD98 alongside NF-κB activation, and iii) lessening Con A-induced consumption of GSH and GSH peroxidase and generation of oxidative stress products (MDA, 4-HNE, NOx) in the liver. In summary, JAK inhibition by RXB led to eminent protection of the liver against Con A-deleterious manifestations primarily via curbing the inflammatory cytokine storm driven by TNF-α, IFN-γ and IL-17A.

Concanavalin A/toxicity , Cytokine Release Syndrome/chemically induced , Cytokine Release Syndrome/drug therapy , Nitriles/pharmacology , Pyrazoles/pharmacology , Pyrimidines/pharmacology , Aldehydes/metabolism , Animals , Chemical and Drug Induced Liver Injury , Dose-Response Relationship, Drug , Inflammation/chemically induced , Liver/drug effects , Liver/metabolism , Male , Malondialdehyde/metabolism , Mice , Mice, Inbred BALB C , Nitrates/metabolism , Nitriles/administration & dosage , Nitrites/metabolism , Oxidative Stress , Peroxidase/metabolism , Pyrazoles/administration & dosage , Pyrimidines/administration & dosage
Sci Rep ; 11(1): 3847, 2021 02 15.
Article in English | MEDLINE | ID: covidwho-1242037


Ruxolitinib is the first janus kinase 1 (JAK1) and JAK2 inhibitor that was approved by the United States Food and Drug Administration (FDA) agency for the treatment of myeloproliferative neoplasms. The drug targets the JAK/STAT signalling pathway, which is critical in regulating the gliogenesis process during nervous system development. In the study, we assessed the effect of non-maternal toxic dosages of ruxolitinib (0-30 mg/kg/day between E7.5-E20.5) on the brain of the developing mouse embryos. While the pregnant mice did not show any apparent adverse effects, the Gfap protein marker for glial cells and S100ß mRNA marker for astrocytes were reduced in the postnatal day (P) 1.5 pups' brains. Gfap expression and Gfap+ cells were also suppressed in the differentiating neurospheres culture treated with ruxolitinib. Compared to the control group, adult mice treated with ruxolitinib prenatally showed no changes in motor coordination, locomotor function, and recognition memory. However, increased explorative behaviour within an open field and improved spatial learning and long-term memory retention were observed in the treated group. We demonstrated transplacental effects of ruxolitinib on astrogenesis, suggesting the potential use of ruxolitinib to revert pathological conditions caused by gliogenic-shift in early brain development such as Down and Noonan syndromes.

Astrocytes/drug effects , Learning/drug effects , Maternal Exposure , Memory/drug effects , Neurogenesis/drug effects , Nitriles/administration & dosage , Protein Kinase Inhibitors/administration & dosage , Pyrazoles/administration & dosage , Pyrimidines/administration & dosage , Age Factors , Animals , Astrocytes/metabolism , Behavior, Animal/drug effects , Biomarkers , Female , Janus Kinases/antagonists & inhibitors , Male , Maternal Exposure/adverse effects , Mice , Neurogenesis/genetics , Nitriles/adverse effects , Organ Specificity/drug effects , Pregnancy , Protein Kinase Inhibitors/adverse effects , Pyrazoles/adverse effects , Pyrimidines/adverse effects
Naunyn Schmiedebergs Arch Pharmacol ; 394(3): 561-567, 2021 03.
Article in English | MEDLINE | ID: covidwho-1235720


Coronavirus disease 2019 (COVID-19) has been characterized by lymphopenia as well as a proinflammatory cytokine storm, which are responsible for the poor prognosis and multiorgan defects. The transcription factor nuclear factor-κB (NF-κB) modulates the functions of the immune cells and alters the gene expression profile of different cytokines in response to various pathogenic stimuli, while many proinflammatory factors have been known to induce NF-κB signalling cascade. Besides, NF-κB has been known to potentiate the production of reactive oxygen species (ROS) leading to apoptosis in various tissues in many diseases and viral infections. Though the reports on the involvement of the NF-κB signalling pathway in COVID-19 are limited, the therapeutic benefits of NF-κB inhibitors including dexamethasone, a synthetic form of glucocorticoid, have increasingly been realized. Considering the fact, the abnormal activation of the NF-κB resulting from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection might be associated with the pathogenic profile of immune cells, cytokine storm and multiorgan defects. Thus, the pharmacological inactivation of the NF-κB signalling pathway can strongly represent a potential therapeutic target to treat the symptomatology of COVID-19. This article signifies pharmacological blockade of the phosphorylation of inhibitor of nuclear factor kappa B kinase subunit beta (IKKß), a key downstream effector of NF-κB signalling, for a therapeutic consideration to attenuate COVID-19.

COVID-19 Drug Treatment , Drug Delivery Systems/trends , I-kappa B Kinase/antagonists & inhibitors , NF-kappa B/antagonists & inhibitors , Signal Transduction/physiology , Animals , COVID-19/epidemiology , COVID-19/metabolism , Cytokine Release Syndrome/drug therapy , Cytokine Release Syndrome/epidemiology , Cytokine Release Syndrome/metabolism , Heterocyclic Compounds, 3-Ring/administration & dosage , Humans , I-kappa B Kinase/metabolism , Lymphopenia/drug therapy , Lymphopenia/epidemiology , Lymphopenia/metabolism , NF-kappa B/metabolism , Nitriles/administration & dosage , Pyridines/administration & dosage , Signal Transduction/drug effects , Sulfones/administration & dosage