ABSTRACT
The aim of this study was to explore the effects of herbal drug pharmacokinetic interactions on the biotransformation of molnupiravir and its metabolite ß-D-N4-hydroxycytidine (NHC) in the blood and brain. To investigate the biotransformation mechanism, a carboxylesterase inhibitor, bis(4-nitrophenyl)phosphate (BNPP), was administered. Not only molnupiravir but also the herbal medicine Scutellaria formula-NRICM101 is potentially affected by coadministration with molnupiravir. However, the herb-drug interaction between molnupiravir and the Scutellaria formula-NRICM101 has not yet been investigated. We hypothesized that the complex bioactive herbal ingredients in the extract of the Scutellaria formula-NRICM101, the biotransformation and penetration of the bloodbrain barrier of molnupiravir are altered by inhibition of carboxylesterase. To monitor the analytes, ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLCMS/MS) coupled with the microdialysis method was developed. Based on the dose transfer from humans to rats, a dose of molnupiravir (100 mg/kg, i.v.), molnupiravir (100 mg/kg, i.v.) + BNPP (50 mg/kg, i.v.), and molnupiravir (100 mg/kg, i.v.) + the Scutellaria formula-NRICM101 extract (1.27 g/kg, per day, for 5 consecutive days) were administered. The results showed that molnupiravir was rapidly metabolized to NHC and penetrated into the brain striatum. However, when concomitant with BNPP, NHC was suppressed, and molnupiravir was enhanced. The blood-to-brain penetration ratios were 2% and 6%, respectively. In summary, the extract of the Scutellaria formula-NRICM101 provides a pharmacological effect similar to that of the carboxylesterase inhibitor to suppress NHC in the blood, and the brain penetration ratio was increased, but the concentration is also higher than the effective concentration in the blood and brain.
ABSTRACT
Background: Zotatifin (eFT226) is a potent and selective inhibitor of eukaryotic initiation factor 4A (eIF4A), a host RNA helicase required for SARS-CoV-2 replication. Zotatifin selectively inhibits translation of ribonucleic acids (RNAs) containing specific short polypurine motifs in their 5-prime (5') regions. Two such highly conserved motifs are found in the SARS-CoV-2 genome. Zotatifin is currently being evaluated in a Phase 1b dose escalation study in 36 patients with mild to moderate COVID disease. In this in vitro study, we evaluated the selectivity of zotatifin's inhibition of SARS-CoV-2 translation, the antiviral activity of zotatifin alone against different human coronaviruses and the antiviral activity of zotatifin in combination with other antivirals against SARSCoV-2. Method(s): The selectivity of zotatifin for viral translation was evaluated in a cell-based reporter assay wherein luciferase translation was driven by 5'-sequences from SARS-CoV-2 or tubulin, a housekeeping gene. The antiviral activity of zotatifin was evaluated against SARS-CoV-1, SARS-CoV-2 variants (Wash/1/2020 (ancestral), delta, omicron BA.2), MERS-CoV and HCoV-299E in primary or established cell lines using cytopathic effect or infectious virus as endpoints. The antiviral activity of zotatifin in combination with remdesivir, N-hydroxycytidine (NHC;active nucleoside analogue metabolite of molnupiravir), nirmatrelvir, baricitinib or sotrovimab was evaluated against SARS-CoV-2 and analyzed by the method of Pritchard and Shipman. Result(s): Zotatifin inhibited the translation of the SARS-CoV-2 luciferase reporter construct with a mean IC50 of 3 nM and was ~14-fold less potent in inhibiting the tubulin reporter construct. Zotatifin potently inhibited the replication of all human coronaviruses tested with 50% effective concentrations (EC50s) ranging from 0.016 to 37.3 nM. The 50% cytotoxic concentration (CC50) value for zotatifin was 250 to >100,000 nM, yielding selectivity indices of 7 to >6250. Zotatifin was ~20 to >100-fold more potent than remdesivir, nirmatrelvir or NHC (figure) and demonstrated additive interactions when combined with remdesivir, NHC, nirmatrelvir, baricitinib or sotrovimab in vitro. Conclusion(s): The potent broad-spectrum activity of zotatifin against a variety of human coronaviruses and additive activity when combined with different anti-SARS-CoV-2 antivirals highlight the advantages of eIF4A as a target and warrant further evaluation in human clinical trials.
ABSTRACT
Molnupiravir, a broad-spectrum antiviral is an isopropyl ester prodrug of beta-D-N4-hydroxycytidine. Molnupiravir targets RNA-dependent RNA-polymerase enzyme of the viruses. A new stability-indicating HPLC-method was developed to determine related substances and assay of molnupiravir. Separation was achieved by using Shim-pack GWS C18 column. The method was validated according to current ICH requirements. The calibration plot gave a linear relationship for all known analytes over the concentration range from LOQ to 200%. LOD and LOQ for all known analytes were found in 0.05-0.08 microg mL-1 and 0.12-0.20 microg mL-1, respectively, the mean recovery was found to be 97.79-102.44 %. Study showed that the method, results of robustness, solution stability studies are precise and within the acceptable limits. Molnupiravir was found to degrade in acid, alkali, and oxidative conditions, and was stable in thermal, moisture, and photolytic degradation condition. The method is simple, accurate, precise, and reproducible for routine purity analysis of drug-samples.Copyright © 2022 Indian Drug Manufacturers' Association. All rights reserved.
ABSTRACT
Molnupiravir is an antiviral agent recently used for treating COVID-19. Here, we demonstrate that N4-hydroxycytidine (NHC), a molnupiravir metabolite, treated with cytidine deaminase (CDA) induced Cu(II)-mediated oxidative DNA damage in isolated DNA. A colorimetric assay revealed hydroxylamine generation from CDA-treated NHC. The site specificity of DNA damage also suggested involvement of hydroxylamine in the damage. Furthermore, Cu(I) and H2O2 play an important role in the DNA damage. We propose oxidative DNA damage via CDA-mediated metabolism as a possible mutagenic mechanism of NHC, highlighting the need for careful risk assessment of molnupiravir use in therapies for viral diseases including COVID-19.
ABSTRACT
Abstract: The recent emergence of the severe acute respiratory disease caused by a novel coronavirus remains a concern posing many challenges to public health and the global economy. The resolved crystal structure of the main protease of SARS-CoV-2 or SCV2 (Mpro) has led to its identification as an attractive target for designing potent antiviral drugs. Herein, we provide a comparative molecular impact of hydroxychloroquine (HCQ), remdesivir, and β-D-N4-Hydroxycytidine (NHC) binding on SCV2 Mpro using various computational approaches like molecular docking and molecular dynamics (MD) simulation. Data analyses showed that HCQ, remdesivir, and NHC binding to SARS-CoV-2 Mpro decrease the protease loop capacity to fluctuate. These binding influences the drugs' optimum orientation in the conformational space of SCV2 Mpro and produce noticeable steric effects on the interactive residues. An increased hydrogen bond formation was observed in SCV2 Mpro–NHC complex with a decreased receptor residence time during NHC binding. The binding mode of remdesivir to SCV2 Mpro differs from other drugs having van der Waals interaction as the force stabilizing protein–remdesivir complex. Electrostatic interaction dominates in the SCV2 Mpro−HCQ and SCV2 Mpro–NHC. Residue Glu166 was highly involved in the stability of remdesivir and NHC binding at the SCV2 Mpro active site, while Asp187 provides stability for HCQ binding. © 2022, Pleiades Publishing, Ltd.
ABSTRACT
Introduction. Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus (severe acute respiratory syndrome-related coronavirus 2). COVID-19 is now expected to stay with us for many years as a recurring disease. Molnupiravir and favipiravir are oral antiviral drugs with anti-RNA polymerase activity. The Russian Health Ministry has approved molnupiravir and favipiravir for the treatment of COVID-19. The study describes development and validation of high-performance liquid chromatography – tandem mass spectrometry (HPLC-MS/MS) method for the simultaneous determination of β-D-N4-Hydroxycytidine and favipiravir in human blood plasma. The method could be applied in pharmacokinetic study of molnupiravir and favipiravir. Aim. The aim of this study is to develop and validate a HPLC-MS/MS bioanalytical method for the determination of β-D-N4-Hydroxycytidine and favipiravir in human plasma. Materials and methods. The determination of β-D-N4-Hydroxycytidine and favipiravir in human plasma by HPLC-MS/MS. The samples were processed by 0.1 % formic acid in acetonitrile. Internal standard: promethazine. Mobile phase: 0.01 mol/L Ammonium formate buffer solution (Eluent A), 0.1 % formic acid and 0.08 % aqueous ammonia in water/acetonitrile 10: 90 (Eluent B). Column: Shim-pack GWS C18, 150 × 4.6 mm, 5 μm. Analytical range: 50.00–10000.00 ng/mL for β-D-N4-Hydroxycytidine, 250.00–20000.00 ng/mL for favipiravir in human plasma. Ionization source: electrospray ionization. Detection conditions: 260.00 m/z → 82.10 m/z, 260.00 m/z → 111.00 m/z, 260.00 m/z → 127.95 m/z (β-D-N4-Hydroxycytidine);156.15 m/z → 65.95 m/z, 156.15 m/z → 85.00 m/z, 156.15 m/z → 113.10 m/z (favipiravir);285.05 m/z → 198.05 m/z (promethazine). Results and discussion. This method was validated by selectivity, suitability of reference standard, matrix effect, calibration curve, accuracy, precision, spike recovery, the lower limit of quantification, carry-over effect and stability. Conclusion. The HPLC-MS/MS method for quantitative determination of β-D-N4-Hydroxycytidine and favipiravir in human plasma was developed and validated. The analytical range was 50.00–10000.00 ng/mL for β-D-N4-Hydroxycytidine, 250.00–20000.00 ng/mL for favipiravir in human plasma. This method was applied to investigate the pharmacokinetics of molnupiravir and favipiravir. © Komarov T. N., Karnakova P. K., Archakova O. A., Shchelgacheva D. S., Bagaeva N. S., Shohin I. E., Zaslavskaya K. Ya., Bely P. A., 2023.
ABSTRACT
Molnupiravir is one of the drugs for the etiotropic therapy of a new coronavirus infection COVID-19. It has confirmed its clinical efficacy in the treatment of patients with mild and moderate COVID-19, including those who are at high risk of progressing to severe disease. The aim of the study was to evaluate bioequivalence of the generic drug molnupiravir ALARIO-TL and the original drug Lagevrio with a single oral administration in healthy volunteers. Materials and methods. This bioequivalence study was an open, randomized, two-period crossover study. In each of the two periods, volunteers received a single dose of the test drug, or reference drug molnupiravir, in the form of capsules at the dose of 200 mg. The washout period between the doses was 3 days. To determine pharmacokinetic (PK) parameters and bioequivalence, the concentration the concentration of N-hydrozycytidine (NHC), the main molnupiravir metabolit in the blood plasma of volunteers was evaluated. The blood plasma sampling was carried out in the range from 0 to 16 hours in each of the study periods. Bioequivalence was assessed by comparing 90% confidence intervals (CIs) for the ratio of geometric means of AUC(0-16) and Cmax of the test drug and reference drugs with the established equivalence limits of 80.00 - 125.00%. Results. A total of 28 healthy male volunteers were included in the study. According to the results of the statistical analysis, after the administration of the test and reference drugs, the 90% CIs for the ratio of the geometric means of AUC (0-16) and Cmax were 96.31% - 113.64% and 91.37% - 114.8%, respectively. These intervals fit within the established limits of 80.00-125.00%, which confirms the bioequivalence of the drugs. When comparing the frequency of the individual adverse events registration, no significant differences were found out after the administration of the test and reference drugs. Conclusion. Based on the results of this study, it can be concluded that the test and reference drugs of molnupiravir are bioequivalent. In addition, the data obtained indicate that the drugs have similar safety profiles.Copyright © 2022 Volgograd State Medical University, Pyatigorsk Medical and Pharmaceutical Institute. All rights reserved.
ABSTRACT
The nucleoside analog ß-D-N4-hydroxycytidine is the active metabolite of the prodrug molnupiravir and is accepted as an efficient drug against COVID-19. Molnupiravir targets the RNA-dependent RNA polymerase (RdRp) enzyme, which is responsible for replicating the viral genome during the replication process of certain types of viruses. It works by disrupting the normal function of the RdRp enzyme, causing it to make mistakes during the replication of the viral genome. These mistakes can prevent the viral RNA from being transcribed, converted into a complementary DNA template, translated, or converted into a functional protein. By disrupting these crucial steps in the viral replication process, molnupiravir can effectively inhibit the replication of the virus and reduce its ability to cause disease. This review article sheds light on the impact of molnupiravir and its metabolite on SARS-CoV-2 variants of concern, such as delta, omicron, and hybrid/recombinant variants. The detailed mechanism and molecular interactions using molecular docking and dynamics have also been covered. The safety and tolerability of molnupiravir in patients with comorbidities have also been emphasized.
ABSTRACT
Drug repurposing approach was applied to find a potent antiviral agent against RNA viruses such as SARS-CoV-2, influenza viruses and dengue virus with a concise strategy of small change in parent molecular structure. For this purpose, ß-D-N4-hydroxycytidine (NHC, 1) with a broad spectrum of antiviral activity was chosen as the parent molecule. Among the prepared NHC analogs (8a-g, and 9) from uridine, ß-D-N4-O-isobutyrylcytidine (8a) showed potent activity against SARS-CoV-2 (EC50 3.50 µM), Flu A (H1N1) (EC50 5.80 µM), Flu A (H3N2) (EC50 7.30 µM), Flu B (EC50 3.40 µM) and DENV-2 (EC50 3.95 µM) in vitro. Furthermore, its potency against SARS-CoV-2 was >5-fold, 3.4-fold, and 3-fold compared to that of NHC (1), MK-4482 (2), and remdesivir (RDV) in vitro, respectively. Ultimately, compound 8a was expected to be a potent inhibitor toward RNA viruses as a viral mutagenic agent like MK-4482.
Subject(s)
COVID-19 , Influenza A Virus, H1N1 Subtype , Humans , SARS-CoV-2 , Influenza A Virus, H3N2 Subtype , Virus Replication , Antiviral Agents/chemistryABSTRACT
Molnupiravir is an antiviral agent recently used for treating coronavirus disease 2019 (COVID-19). Here, we demonstrate that N-4-hydroxycytidine (NHC), a molnupiravir metabolite, treated with cytidine deaminase (CDA) induced Cu(II)mediated oxidative DNA damage in isolated DNA. A colorimetric assay revealed hydroxylamine generation from CDA-treated NHC. The site specificity of DNA damage also suggested involvement of hydroxylamine in the damage. Furthermore, Cu(I) and H2O2 play an important role in the DNA damage. We propose oxidative DNA damage via CDA-mediated metabolism as a possible mutagenic mechanism of NHC, highlighting the need for careful risk assessment of molnupiravir use in therapies for viral diseases, including COVID-19.
ABSTRACT
INTRODUCTION: Molnupiravir (MOV) is a broad-spectrum oral antiviral agent approved for the treatment of COVID-19. The results from in vitro and in vivo studies suggested MOV activity against many RNA viruses such as influenza virus and some alphaviruses agents of epidemic encephalitis. MOV is a prodrug metabolized into the ribonucleoside analog ß-D-N4-hydroxycytidine. It is incorporated into the viral RNA chain causing mutations impairing coding activity of the virus, thereby inhibiting viral replication. AREAS COVERED: This review analyzes the in vitro and in vivo studies that have highlighted the efficacy of MOV and the main pre-authorization randomized controlled trials evaluating its safety, tolerability, and pharmacokinetics, as well as its antiviral efficacy against SARS-COV-2 infection. EXPERT OPINION: MOV is an antiviral agent with an excellent tolerability profile with few drug-drug interactions. Treatment of mild-to-moderate COVID-19 can benefit from MOV administration in the precocious phases of the disease, prior to the trigger of an aberrant immune response responsible for the parenchymal damage to pulmonary and extrapulmonary tissues. However, its suspected mutagenic effect can be a factor limiting its use at least in selected populations and studies on its teratogen effects should be planned before it is authorized for use in the pediatric population or in pregnant women.
Subject(s)
COVID-19 , Child , Female , Humans , Pregnancy , SARS-CoV-2 , Hydroxylamines , Antiviral Agents/adverse effectsABSTRACT
Objective: The mechanism of action, metabolic kinetics, efficacy, safety and drug-drug interaction of molnupiravir were reviewed to provide a basis for clinical use. Method(s): Literature related to molnupiravir was systematically searched in Chinese Clinical Trial Registry, clinicaltrials.gov, Pubmed, Chinese Journal Full-text Database (CNKI) and Wanfang database, and the relevant information was reviewed. Results & Conclusion(s): Molnupiravir was the world's first small-molecule oral drug for COVID-19, which had been approved or authorized for emergency use in more than 40 countries all over the world. Molnupiravir was a ribonucleoside analogue that could be caused mutations in RNA products by viral RNA polymerase, and thus halt viral replication. Clinical trial results showed that molnupiravir could be reduced hospitalization and mortality rates in patients with mild and moderate COVID-19, and might be effective against SARS-CoV-2 mutant strains.Molnupiravir had good safety and tolerability, to provide reference for the treatment of COVID-19 in the future. Copyright © 2022, Chinese Journal of New Drugs Co. Ltd. All right reserved.
ABSTRACT
Molnupiravir (MOV) has received FDA's Emergency Use Authorization for the treatment of COVID-19, which is caused by SARS-CoV-2 infection. MOV is a prodrug of the ribonucleoside analog, Nhydroxycytidine (NHC). Upon phosphorylation, NHC incorporates into nascent viral RNA during replication triggering “catastrophic” mutation of the viral genome. However, NHC can also enter the deoxy-ribonucleotide pool, become incorporated into DNA, and cause DNA mutations. In nonclinical safety assessments, MOV was positive (i.e., mutagenic) in the Ames assay but negative in regulatory in vitro and in vivo micronucleus assays. Multiple in vitro studies conducted in bacteriophages, bacteria, fungi, and mammalian cells have reported that NHC can induce DNA mutations, mainly A:T>G:C transitions. We used a recently developed error-corrected wholegenome sequencing technique for detecting mutations induced by MOV and NHC in cultures of E. coli, mouse L5178YTk+/-, and human TK6 cells. Treatment of bacterial and mammalian cultures (for 4 hours and 5 days, respectively) with either MOV or NHC increased mutation frequencies in a dose-dependent manner in all three models. The majority of induced mutations were A:T>G:C, consistent with the type of mutation caused by incorporation of dNHC opposite to dA in the first round of DNA replication and incorporation of dG opposite to dNHC in the subsequent round(s) of DNA replication. Trinucleotide mutational signatures in MOV/NHC-treated cells were similar in mouse and human cells and different from the background spontaneous mutational signatures in parental cell cultures. The specific mutational signature was evident in mammalian cells exposed to NHC concentrations comparable to those observed in the plasma of human subjects who received clinical doses of MOV. This data indicates more well-controlled rodent and clinical studies of MOV/NHC-induced mutagenicity should be done in the interest of public health safety.
ABSTRACT
Since the late 1950s researchers have developed nucleoside analogues to target viral replication and infections. Following the HIV/AIDS outbreak several early nucleoside analogues were employed. These compounds can interfere with viral transcription and translation events targeting DNA and RNA polymerases. The downside is that this is not necessarily restricted to the viral polymerases but can also target the host polymerases and have detrimental effects causing for instance mutations and carcinogenicity. In a retrospective study, we applied the ToxTracker® genotoxicity reporter assay to assess the potential of a selection of representative nucleoside analogues to cause genotoxicity. Among the early nucleoside analogues, several triggered a genotoxic response, in line with historical data. Generally, later generation nucleoside analogues did not trigger the genotoxicity reporters in ToxTracker but in some cases the reporters for oxidative stress and protein damage were activated. Remdesivir and Molnupiravir, two nucleoside analogues that are currently being repurposed for Covid-19 treatment, were designed as pro-drugs and will after metabolization release their respective active metabolites. Neither pro-drug nor their metabolites triggered any genotoxicity biomarkers but the metabolite of Molnupiravir (EIDD-1931) did trigger oxidative stress, p53 and protein damage at concentrations relevant for human treatment. Overall, the ToxTracker data were in line with the in vivo micronucleus assay while the AMES test for the nucleoside analogues had problems to assess their mutagenic potential. Nucleoside analogues continue to be attractive treatment options for viral infections. ToxTracker readily distinguished between the genotoxic analogues and those with different profiles and provides a basis for clustering and potency ranking, offering a comprehensive tool to assess the toxicity of nucleoside analogues.
ABSTRACT
Molnupiravir is a ß-d-N4-hydroxycytidine-5'-isopropyl ester (NHC) compound that exerts antiviral activity against various RNA viruses such as influenza, SARS, and Ebola viruses. Thus, the repurposing of Molnupiravir has gained significant attention for combatting infection with SARS-CoV-2, the etiological agent of COVID-19. Recently, Molnupiravir was granted authorization for the treatment of mild-to-moderate COVID-19 in adults. Findings from in vitro experiments, in vivo studies and clinical trials reveal that Molnupiravir is effective against SARS-CoV-2 by inducing viral RNA mutagenesis, thereby giving rise to mutated complementary RNA strands that generate non-functional viruses. To date, the data collectively suggest that Molnupiravir possesses promising antiviral activity as well as favorable prophylactic efficacy, attributed to its effective mutagenic property of disrupting viral replication. This review discusses the mechanisms of action of Molnupiravir and highlights its clinical utility by disabling SARS-CoV-2 replication, thereby ameliorating COVID-19 severity. Despite relatively few short-term adverse effects thus far, further detailed clinical studies and long-term pharmacovigilance are needed in view of its mutagenic effects.
Subject(s)
COVID-19 Drug Treatment , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Cytidine/analogs & derivatives , Humans , Hydroxylamines , SARS-CoV-2ABSTRACT
Background: Molnupiravir (MOV), the orally administered prodrug of the antiviral ribonucleoside analogue, N-hydroxycytidine (NHC) has received emergency use authorization for treatment of COVID-19. NHC inhibits viral replication by introduction of random transition errors across the viral genome, resulting in non-infectious virus. In the Phase II/III (MOVe-OUT) study, non-hospitalized participants received MOV or placebo (PBO) for 5 days and followed to Day 29. Viral RNA was sequenced to determine the rate, distribution and type of viral errors observed. Methods: SARS-CoV-2 RNA isolated from nasopharyngeal swabs was quantified by RT-PCR followed by complete genome NGS using the Ion AmpliSeq SARS-CoV-2 Research panel and Ion Torrent sequencing. To distinguish between nucleotide errors resulting from the mechanism of action of MOV and those potentially associated with reduced susceptibility to NHC, two different analyses were used. To measure impact of MOV on accumulation of low-frequency errors in the viral quasispecies, nucleotide variants were identified using VarScan 2.4 mutation caller with 0.4% minimum variant allele frequency cut-off. Resistance-associated changes were identified as amino acid substitutions occurring in D3 or D5 samples from ≥2 participants with a frequency of ≥5% of NGS reads. Phenotypic analysis of selected amino acid substitutions was performed using a replicon model. Results: NGS results showed a relationship between the number of random errors across the viral genome with increasing MOV dose. By Day 5 the mean number of viral genome errors were 21, 83, 129 and 223 in the PBO, 200, 400 and 800 mg groups, respectively. Among the sequence changes observed, the majority were transitions errors, consistent with MOV's mechanism of action. After MOV treatment, few treatment-emergent amino acid substitutions were identified in the viral replicase genes. These included nsp12 (T731I) and nsp14 (A220S/T/V, V466I, S503L/P);none associated with loss of susceptibility to MOV. Changes in spike protein in both PBO and MOV groups were at sites previously described in circulating variants. Conclusion: Consistent with the mechanism of action, MOV treatment resulted in a dose-dependent increase in transition errors across the SARS-CoV-2 genome. No resistance-associated mutations were identified in the viral replicase and no evidence that MOV treatment selected for unique mutations in spike protein not previously observed in circulating variants.
ABSTRACT
Background: Molnupiravir, a prodrug of the broadly active, direct-acting antiviral, ribonucleoside analogue EIDD-1931, is a promising COVID-19 drug. Given the primary route of SARS-CoV-2 transmission through respiratory droplets we evaluated EIDD-1931 PK in saliva, nasal secretions and tears of patients with mild-to-moderate COVID-19 through the phase Ib/IIa AGILE platform (NCT04746183). Methods: Patients with PCR-confirmed SARS-CoV-2 infection, within 5 days of symptom onset with mild-to-moderate disease were randomised to oral molnupiravir 300, 600 or 800 mg twice daily. Plasma and non-plasma (saliva, nasal and tear swabs) samples were collected pre-dose, 0.5, 1, 2, and 4 hours post-dose on study days 1 and 5 and molnupiravir and EIDD-1931 measured by LC/MS (lower limit of quantification, 2.5 ng/mL). PK parameters were determined (Phoenix 64, WinNonlin, v. 8.3) and non-plasma:plasma (NP:P) ratios (based on AUC0-4) calculated. Relationships between paired non-plasma and plasma samples were evaluated by linear regression. Results: Twelve participants (n=4 per dose;75% female) completed the study contributing 111, 112 and 97 saliva, nasal and tear samples, respectively. Molnupiravir was detected in 11% of saliva samples [median (range) 4.86 ng/mL (2.63-31.44)] and not evaluated in swabs. Quantifiable EIDD-1931, following molnupiravir 300, 600 and 800 mg twice daily were i) saliva: 17.7 (2.8-133), 16.6 (2.9-469), 25.8 (4.0-230) ng/mL, ii) nasal swabs: 182 (18-1700), 136 (18-917), 295 (24-1879) ng/mL and iii) tears: 297 (24-1650), 176 (16-1260), 307 (32-2760) ng/mL. PK parameters are shown (Table 1). Median (range, CV%) pooled NP:P ratio for saliva was 0.03 (0.01-0.11, 60%;n=16). Nasal and tear ratios were 6-fold higher with values of 0.21 (0.05-0.73, 70%;n=17) and 0.22 (0.09-1.05, 92%;n=12), respectively. Non-plasma and plasma concentrations were significantly correlated (r2: 0.360-0.677;p<0.0001). Of measured saliva, nasal and tear samples, 6, 50 and 61%, respectively were within or above the EIDD-1931 EC90 against SARS-CoV-2 in primary human airway epithelia cultures (approximately 0.5-1 μ M ≈ 130-260 ng/mL). Conclusion: This is the first report of EIDD-1931 PK at sites of initial SARS-CoV-2 exposure in patients with COVID-19. Investigations of PK/PD relationships are warranted;however, these data suggest therapeutic concentrations are potentially achieved in nasal and tear compartments, but not saliva and have important implications for prophylactic coverage.
ABSTRACT
Broad-spectrum antiviral agents targeting viral RNA-dependent RNA polymerase (RdRp) are expected to be a key therapeutic strategy in the ongoing coronavirus disease 2019 (COVID-19) pandemic and its future variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19. Molnupiravir is a nucleoside analog that in vivo experiments have been reported to inhibit the replication of SARS-CoV-2, the virus that causes COVID-19. Clinical trials of molnupiravir as a therapy for patients with mild-to-moderate COVID-19 also suggest its significant therapeutic efficacy in comparison to placebo. Molnupiravir is lethally mutagenic against viral RNA, but its effect on host cell DNA is being questioned. Herein, the safety concerns of molnupiravir are discussed with recent findings from published reports and clinical trials. The unchanged efficacy of molnupiravir against mutated SARS-CoV-2 variants is also highlighted. With its administration via the oral route, molnupiravir is expected to turn the tide of the COVID-19 pandemic.
Subject(s)
COVID-19 Drug Treatment , SARS-CoV-2 , Antiviral Agents/adverse effects , Cytidine/analogs & derivatives , Humans , Hydroxylamines , Mutagens/pharmacology , Pandemics , Pharmaceutical PreparationsABSTRACT
This review considers antiviral nucleoside analog drugs, including ribavirin, favipiravir, and molnupiravir, which induce genome error catastrophe in SARS-CoV or SARS-CoV-2 via lethal mutagenesis as a mode of action. In vitro data indicate that molnupiravir may be 100 times more potent as an antiviral agent than ribavirin or favipiravir. Molnupiravir has recently demonstrated efficacy in a phase 3 clinical trial. Because of its anticipated global use, its relative potency, and the reported in vitro "host" cell mutagenicity of its active principle, ß-d-N4-hydroxycytidine, we have reviewed the development of molnupiravir and its genotoxicity safety evaluation, as well as the genotoxicity profiles of three congeners, that is, ribavirin, favipiravir, and 5-(2-chloroethyl)-2'-deoxyuridine. We consider the potential genetic risks of molnupiravir on the basis of all available information and focus on the need for additional human genotoxicity data and follow-up in patients treated with molnupiravir and similar drugs. Such human data are especially relevant for antiviral NAs that have the potential of permanently modifying the genomes of treated patients and/or causing human teratogenicity or embryotoxicity. We conclude that the results of preclinical genotoxicity studies and phase 1 human clinical safety, tolerability, and pharmacokinetics are critical components of drug safety assessments and sentinels of unanticipated adverse health effects. We provide our rationale for performing more thorough genotoxicity testing prior to and within phase 1 clinical trials, including human PIG-A and error corrected next generation sequencing (duplex sequencing) studies in DNA and mitochondrial DNA of patients treated with antiviral NAs that induce genome error catastrophe via lethal mutagenesis.
Subject(s)
Antiviral Agents/adverse effects , COVID-19 Drug Treatment , Cytidine/analogs & derivatives , DNA Damage/drug effects , Hydroxylamines/adverse effects , Nucleosides/adverse effects , SARS-CoV-2/genetics , Amides/adverse effects , Amides/therapeutic use , Antiviral Agents/therapeutic use , Cytidine/adverse effects , Cytidine/therapeutic use , Deoxyuridine/adverse effects , Deoxyuridine/analogs & derivatives , Deoxyuridine/therapeutic use , Genome, Human/drug effects , Humans , Hydroxylamines/therapeutic use , Mutagenesis/drug effects , Nucleosides/therapeutic use , Pyrazines/adverse effects , Pyrazines/therapeutic use , Ribavirin/adverse effects , Ribavirin/therapeutic use , SARS-CoV-2/drug effectsABSTRACT
In light of the recent global pandemic, Molnupiravir (MPV) or EIDD-2801, developed for the treatment of patients with uncomplicated influenza, is now being trialled for the treatment of infections caused by highly pathogenic coronaviruses, including COVID-19. A sensitive LC-MS/MS method was developed and validated for the simultaneous quantification of MPV and its metabolite ß-d-N4-hydroxycytidine (NHC) in human plasma and saliva. The analytes were extracted from the matrices by protein precipitation using acetonitrile. This was followed by drying and subsequently injecting the reconstituted solutions onto the column. Chromatographic separation was achieved using a polar Atlantis C18 column with gradient elution of 1 mM Ammonium acetate in water (pH4.3) and 1 mM Ammonium acetate in acetonitrile. Analyte detection was conducted in negative ionisation mode using SRM. Analysis was performed using stable isotopically labelled (SIL) internal standards (IS). The m/z transitions were: MPV (328.1â126.0), NHC (258.0â125.9) and MPV-SIL (331.0â129.0), NHC-SIL (260.9â128.9). Validation was over a linear range of 2.5-5000 ng/ml for both plasma and saliva. Across four different concentrations, precision and accuracy (intra- and inter-day) were 15%; and recovery of both analytes from plasma and saliva was between 95% and 100% and 65-86% respectively. Clinical pharmacokinetic studies are underway utilising this method for determination of MPV and its metabolite in patients with COVID-19 infection.