Molnupiravir increases SARS-CoV-2 genome diversity and complexity: A case-control cohort study.

Molnupiravir, an oral direct-acting antiviral effective in vitro against SARS-CoV-2, has been largely employed during the COVID-19 pandemic, since December 2021. After marketing and widespread usage, a progressive increase in SARS-CoV-2 lineages characterized by a higher transition/transversion ratio, a characteristic signature of molnupiravir action, appeared in the Global Initiative on Sharing All Influenza Data (GISAID) and International Nucleotide Sequence Database Collaboration (INSDC) databases. Here, we assessed the drug effects by SARS-CoV-2 whole-genome sequencing on 38 molnupiravir-treated persistently positive COVID-19 outpatients tested before and after treatment. Seventeen tixagevimab/cilgavimab-treated outpatients served as controls. Mutational analyses confirmed that SARS-CoV-2 exhibits an increased transition/transversion ratio seven days after initiation of molnupiravir. Moreover we observed an increased G->A ratio compared to controls, which was not related to apolipoprotein B mRNAediting enzyme, catalytic polypeptide-like (APOBEC) activity. In addition, we demonstrated for the first time an increased diversity and complexity of the viral quasispecies.

Safety of RNA-Dependent RNA Polymerase Inhibitors, Molnupiravir and VV116, for Oral Treatment of COVID-19: A Meta-Analysis.

Background: The RNA-dependent RNA polymerase (RdRp) inhibitors, molnupiravir and VV116, have the potential to maximize clinical benefits in the oral treatment of COVID-19. Subjects who consume these drugs may experience an increased incidence of adverse events. This study aimed to evaluate the safety profile of molnupiravir and VV116. Methods: A comprehensive search of scientific and medical databases, such as PubMed Central/Medline, Embase, Web of Science, and Cochrane Library, was conducted to find relevant articles in English from January 2020 to June 2023. Any kind of adverse events reported in the study were pooled and analyzed in the drug group versus the control group. Estimates of risk effects were summarized through the random effects model using Review Manager version 5.2, and sensitivity analysis was performed by Stata 17.0 software. Results: Fifteen studies involving 32,796 subjects were included. Eleven studies were placebo-controlled, and four were Paxlovid-controlled. Twelve studies reported adverse events for molnupiravir, and three studies described adverse events for VV116. The total odds ratio (OR) for adverse events in the RdRp inhibitor versus the placebo-controlled group was 1.01 (95% CI=0.84-1.22; I2=26%), P=0.88. The total OR for adverse events in the RdRp inhibitor versus the Paxlovid-controlled group was 0.32 (95% CI=0.16-0.65; I2=87%), P=0.002. Individual drug subgroup analysis in the placebo-controlled study showed that compared with the placebo group, a total OR for adverse events was 0.97 (95% CI, 0.85-1.10; I2=0%) in the molnupiravir group and 3.77 (95% CI=0.08-175.77; I2=85%) in the VV116 group. Conclusion: The RdRp inhibitors molnupiravir and VV116 are safe for oral treatment of COVID-19. Further evidence is necessary that RdRp inhibitors have a higher safety profile than Paxlovid.

Molnupiravir versus favipiravir in at-risk outpatients with COVID-19: A randomized controlled trial in Thailand.

OBJECTIVES: Evaluate and compare the efficacy and safety of molnupiravir and favipiravir in outpatients with mild to moderate COVID-19 and at risk of severe COVID-19. METHODS: In an open-label, parallel-group, multicenter trial in Thailand, participants with moderate COVID-19 and at least one factor associated with severe COVID-19 were randomly assigned 1:1 to receive oral molnupiravir or oral favipiravir (standard of care). Phone calls for remote symptom assessment were made on Days 6, 15, and 29. Participants with worsening symptoms were instructed to return to the hospital. The primary endpoint was pulmonary involvement by Day 29, as evidenced by ≥2 of the following: dyspnea, oxygen saturation <92% or imaging. RESULTS: Nine hundred seventy-seven participants (487 molnupiravir, 490 favipiravir) were enrolled from 8 July 2022 to 19 January 2023. 98% had received ≥1 dose of COVID-19 vaccine and 83% ≥3 doses. By Day 29, pulmonary involvement occurred in 0% (0/483) in molnupiravir arm versus 1% (5/482) in favipiravir arm (-1.0%; Newcombe 95.2% CI: -2.4% to -0.0%; P = 0.021); all-cause death in 0% (0/483) and <1% (1/482); COVID-19 related hospitalization in <1% (1/483) and 1% (3/482); treatment-related adverse event in 1% (5/483) and 1% (4/486); and serious adverse event in 1% (4/483) and 1% (4/486). CONCLUSIONS: Favipiravir and molnupiravir had a similar efficacy and safety profile. Whether either of the two reduced the risk of complications during the omicron era in this population with a low risk of pulmonary involvement and a high vaccine coverage remains unclear. There were no differences in any of the safety endpoints. THAI CLINICAL TRIALS REGISTRY ID: TCTR20230111009.

A path from synthesis to emergency use authorization of molnupiravir as a COVID-19 therapy.

Coronaviruses are a group of enveloped viruses with non-segmented, single-stranded, and positive-sense RNA genomes. It belongs to the 'Coronaviridae family', responsible for various diseases, including the common cold, SARS, and MERS. The COVID-19 pandemic, which began in March 2020, has affected 209 countries, infected over a million people, and claimed over 50,000 lives. Significant efforts have been made by repurposing several approved drugs including antiviral, to combat the COVID-19 pandemic. Molnupiravir is found to be the first orally acting efficacious drug to treat COVID-19 cases. It was approved for medical use in the UK in November 2021 and other countries, including USFDA, which granted approval an emergency use authorization (EUA) for treating adults with mild to moderate COVID-19 patients. Considering the importance of molnupiravir, the present review deals with its various synthetic strategies, pharmacokinetics, bio-efficacy, toxicity, and safety profiles. The comprehensive information along with critical analysis will be very handy for a wide range of audience including medicinal chemists in the arena of antiviral drug discovery especially anti-viral drugs against any variant of COVID-19.

Comparison of effectiveness and safety of molnupiravir versus sotrovimab for COVID-19: A systematic review and meta-analysis.

BACKGROUND AND AIM: This systematic review and meta-analysis aimed to compare the effectiveness and safety of molnupiravir and sotrovimab in the treatment of patients with coronavirus disease 2019 (COVID-19). METHODS: Cochrane Library, Web of Science, PubMed, medRxiv, and Google Scholar were systematically searched to identify relevant evidence up to December 2023. The risk of bias was assessed using the risk of bias in nonrandomized studies of interventions tool. Data were analyzed using Comprehensive Meta-Analysis (CMA). RESULTS: Our search identified and included 13 studies involving 16166 patients. The meta-analysis revealed a significant difference between the molnupiravir and sotrovimab groups in terms of the mortality rate (odds ratio [OR] = 2.07, 95% confidence interval [CI]: 1.16, 3.70). However, no significant difference was observed between the two groups in terms of hospitalization rate (OR = 0.71, 95% CI: 0.47, 1.06), death or hospitalization rate (OR = 1.51, 95% CI: 0.81, 2.83), and intensive care unit admission (OR = 0.59, 95% CI: 0.07, 4.84). In terms of safety, molnupiravir was associated with a higher incidence of adverse events (OR = 1.67, 95% CI: 1.21, 2.30). CONCLUSION: The current findings indicate that sotrovimab may be more effective than molnupiravir in reducing the mortality rate in COVID-19 patients. However, no statistical difference was observed between the two treatments for other effectiveness outcomes. The certainty of evidence for these findings was rated as low or moderate. Further research is required to provide a better comparison of these interventions in treating COVID-19 patients.

Effect of molnupiravir on SARS-CoV-2 evolution in immunocompromised patients: a retrospective observational study.

INTRODUCTION: Continued SARS-CoV-2 infection among immunocompromised individuals is likely to play a role in generating genomic diversity and the emergence of novel variants. Antiviral treatments such as molnupiravir are used to mitigate severe COVID-19 outcomes, but the extended effects of these drugs on viral evolution in patients with chronic infections remain uncertain. This study investigates how molnupiravir affects SARS-CoV-2 evolution in immunocompromised patients with prolonged infections. METHODS: The study included five immunocompromised patients treated with molnupiravir and four patients not treated with molnupiravir (two immunocompromised and two non-immunocompromised). We selected patients who had been infected by similar SARS-CoV-2 variants and with high-quality genomes across timepoints to allow comparison between groups. Throat and nasopharyngeal samples were collected in patients up to 44 days post treatment and were sequenced using tiled amplicon sequencing followed by variant calling. The UShER pipeline and University of California Santa Cruz genome viewer provided insights into the global context of variants. Treated and untreated patients were compared, and mutation profiles were visualised to understand the impact of molnupiravir on viral evolution. FINDINGS: Patients treated with molnupiravir showed a large increase in low-to-mid-frequency variants in as little as 10 days after treatment, whereas no such change was observed in untreated patients. Some of these variants became fixed in the viral population, including non-synonymous mutations in the spike protein. The variants were distributed across the genome and included unique mutations not commonly found in global omicron genomes. Notably, G-to-A and C-to-T mutations dominated the mutational profile of treated patients, persisting up to 44 days post treatment. INTERPRETATION: Molnupiravir treatment in immunocompromised patients led to the accumulation of a distinctive pattern of mutations beyond the recommended 5 days of treatment. Treated patients maintained persistent PCR positivity for the duration of monitoring, indicating clear potential for transmission and subsequent emergence of novel variants. FUNDING: Australian Research Council.

Virology and safety profile of Molnupiravir at three different doses for treatment of SARS-CoV-2: a systematic review and meta-analysis.

Molnupiravir is incorporated into the viral genome, thereby increasing errors, mismatching, and misdirecting the viral polymerase thereby, halting viral RNA replication of SARS-CoV-2. Following PRISMA guidelines, a thorough literature search was performed on electronic and medical databases from December 2022 till January 2023. Molnupiravir 800 mg showed significance in creating viral RNA error rate at Day 5 (WMD: 4.91; 95% CI; [1.19, 8.63] p = 0.01; I2 = 0%). Similarly, at 400 mg, Molnupiravir creates an RNA error rate (WMD: 2.27; 95% CI; 2.27 [0.50, 4.65] p = 0.02; I2 = 0%). Furthermore, exhibit a significant outcome for mean change in SARS-CoV-2 RNA viral load from baseline in nasopharyngeal sample at 800 mg Molnupiravir on Day 3 (WMD: -0.22; 95% CI; [-0.35, -0.08] p = 0.002; I2 = 0%), Day 5 (WMD: -0.32; 95% CI; [-0.53, -0.11] p = 0.003; I2 = 24%) and overall pooled analysis (WMD: -0.17; 95% CI; [-0.29, 0.33] p = 0.003; I2 = 32%). Moreover, Molnupiravir 400 mg significantly reduced the incidence of death compared to the placebo group (RR: 0.17; 95% CI; [0.07, 0.43] p = 0.0002; I2 = 0%). Molnupiravir effectively treats SARS-CoV-2 patients by eliminating the virus from the host.

A molnupiravir-associated mutational signature in global SARS-CoV-2 genomes.

Molnupiravir, an antiviral medication widely used against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), acts by inducing mutations in the virus genome during replication. Most random mutations are likely to be deleterious to the virus and many will be lethal; thus, molnupiravir-induced elevated mutation rates reduce viral load1,2. However, if some patients treated with molnupiravir do not fully clear the SARS-CoV-2 infections, there could be the potential for onward transmission of molnupiravir-mutated viruses. Here we show that SARS-CoV-2 sequencing databases contain extensive evidence of molnupiravir mutagenesis. Using a systematic approach, we find that a specific class of long phylogenetic branches, distinguished by a high proportion of G-to-A and C-to-T mutations, are found almost exclusively in sequences from 2022, after the introduction of molnupiravir treatment, and in countries and age groups with widespread use of the drug. We identify a mutational spectrum, with preferred nucleotide contexts, from viruses in patients known to have been treated with molnupiravir and show that its signature matches that seen in these long branches, in some cases with onward transmission of molnupiravir-derived lineages. Finally, we analyse treatment records to confirm a direct association between these high G-to-A branches and the use of molnupiravir.

MYC-induced cytidine metabolism regulates survival and drug resistance via cGas-STING pathway in mantle cell lymphoma.

Lymphocyte proliferation and tumourigenesis are dependent on nucleotide synthesis to support DNA, RNA and phospholipid synthesis. Here, we identified that reprogramming of nucleotide metabolism as an important factor divides mantle cell lymphoma (MCL) into two groups with different transcriptional signalling pathways and varying prognoses. We establish a nucleotide metabolism-related prognostic model that includes six genes with different regression coefficients, which significantly predicts prognosis for MCL patients (p < 0.0001). Of these six genes, de novo CTP synthesis pathway enzyme CTPS1 whose inhibitor (STP938) is already in clinical trials for relapsed/refractory lymphomas (NCT05463263) has the highest regression coefficient. An increase in CTPS1 expression predicts adverse overall survival and progression-free survival with independent prognostic significance in 105 primary MCL samples and GEO database (GSE93291). CRISPR CTPS1 knockout causes DNA damage and proliferation defects in MCL. Additionally, MYC positively regulates CTPS1 expression, and TP53-aberrant and ibrutinib-resistant MCL cells also rely on cytidine metabolism. Furthermore, besides the obvious decreased CTP pool caused by CTPS1 deficiency, CTPS1 inhibition may also induce immune-related responses via activating dsDNA-cGAS-STING pathway, which plays a crucial role in impeding tumour growth in MCL patients.

Evaluation of molnupiravir (EIDD-2801) efficacy against SARS-CoV-2 in the rhesus macaque model.

Molnupiravir (EIDD-2801) is a prodrug of a ribonucleoside analogue that is currently being used under a US FDA emergency use authorization for the treatment of mild to moderate COVID-19. We evaluated molnupiravir for efficacy as an oral treatment in the rhesus macaque model of SARS-CoV-2 infection. Twenty non-human primates (NHPs) were challenged with SARS-CoV-2 and treated with 75 mg/kg (n = 8) or 250 mg/kg (n = 8) of molnupiravir twice daily by oral gavage for 7 days. The NHPs were observed for 14 days post-challenge and monitored for clinical signs of disease. After challenge, all groups showed a trend toward increased respiration rates. Treatment with molnupiravir significantly reduced viral RNA levels in bronchoalveolar lavage (BAL) samples at Days 7 and 10. Considering the mild to moderate nature of SARS-CoV-2 infection in the rhesus macaque model, this study highlights the importance of monitoring the viral load in the lung as an indicator of pharmaceutical efficacy for COVID-19 treatments. Additionally, this study provides evidence of the efficacy of molnupiravir which supplements the current ongoing clinical trials of this drug.

Trimethoxy Trityl Groups as a Potent Substituent for Anti-cancer Cytidine Analog Prodrugs.

Methoxy trityl groups are acid-responsive protecting groups that are routinely used in the process of nucleoside analog synthesis. This study investigated the potential of methoxy trityl groups, monomethoxy trityl (MMT), dimethoxy trityl (DMT), and trimethoxy trityl (TMT), as acid-responsive substituents for designing anti-cancer cytidine analog prodrugs. For this purpose, we synthesized six gemcitabine (GEM) derivatives, which were modified either 4-(N)- or 5'-(O)-sites with MMT, DMT, and TMT, as candidates for anti-cancer cytidine analog prodrugs. In vitro dissociation test of methoxy trityl groups clearly showed that the acid responsivity of the methoxy trityl moieties was in the order TMT>DMT>MMT. Furthermore, the rate of 5'-(O)-methoxy tritylation was higher than that of 4-(N)-methoxy tritylation. Along with high acid-responsivity, trimethoxy trityl-O-GEM (TMT-O-GEM) showed superior cytotoxicity against 2D cultured human breast cancer cells (MCF-7 and MDA-MB-231) and human pancreatic cancer cells (AsPC-1) compared to other methoxy-tritylated GEM derivatives. Moreover, TMT-O-GEM suppressed the growth of MCF-7 spheroids compared with trimethoxy trityl-N-GEM (TMT-N-GEM). Both TMT-O-GEM and TMT-N-GEM were negligibly deprotected and metabolized in mouse or human serum after 72 h, indicating that trimethoxy tritylation inhibits deamination by cytidine deaminase. These results indicate that 5'-(O)-trimethoxy tritylation is a potent approach for the development of anti-cancer cytidine analog prodrugs.

Molnupiravir in unvaccinated patients with COVID-19.

Overview of: Jayk Bernal A, Gomes da Silva MM, Musungaie DB, et al Molnupiravir for oral treatment of COVID-19 in nonhospitalized patients. NEJM 2021;doi:10.1056/NEJMoa2116044 [Epub ahead of print 16 Dec 2021].

Molnupiravir: First Approval.

Molnupiravir (Lagevrio®) is an orally-administered antiviral prodrug that inhibits replication of RNA viruses through viral error induction. It is being developed by Merck and Ridgeback Biotherapeutics for the prevention and treatment of Coronavirus disease 2019 (COVID-19). Molnupiravir received its first approval on 4 November 2021 in the UK for the treatment of mild to moderate COVID-19 in adults with a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostic test and who have at least one risk factor for developing severe illness. Molnupiravir is filed for approval and has emergency use authorization for the treatment of COVID-19 in several countries, including the USA, Japan and those in the EU. This article summarizes the milestones in the development of molnupiravir leading to this first approval for COVID-19.

Lethal mutagenesis as an antiviral strategy.

[Figure: see text].