Molnupiravir for the treatment of COVID-19 outpatients: An updated meta-analysis

BACKGROUND

The majority of available data on molnupiravir come from an unvaccinated COVID-19 population. Therefore, we conducted this meta-analysis to integrate evidence from recent randomized controlled trials (RCTs) as well as observational studies stratified by vaccination status to determine the clinical efficacy and safety of molnupiravir in COVID-19 outpatients.

METHODS

We searched PubMed, Embase, the Cochrane Library, medRxiv, and ClinicalTrials.gov from inception to November 2023. We conducted our meta-analysis using RevMan 5.4 with risk ratio (RR) as the effect measure.

RESULTS

We included 8 RCTs and 5 observational studies in our meta-analysis. Molnupiravir reduced the risk of all-cause mortality (RR 0.28; 95% CI: 0.20-0.79, I2 = 0%) but did not decrease the hospitalization rate (RR 0.67; 95% CI: 0.45-1.00, I2 = 53%) in the overall population; in the immunized population, no benefits were observed. Molnupiravir lowered the rate of no recovery (RR 0.78; 95% CI: 0.76-0.81, I2 = 0%) and increased virological clearance at day 5 (RR 2.68; 95% CI: 1.94-4.22, I2 = 85%). There was no increase in the incidence of adverse events.

CONCLUSIONS

Molnupiravir does not decrease mortality and hospitalization rates in immunized patients with COVID-19. However, it does shorten the disease course and increases the recovery rate. The use of molnupiravir will need to be considered on a case-by-case basis in the context of the prevailing social circumstances, the resource setting, drug costs, and the healthcare burden.

Virologic Outcomes with Molnupiravir in Non-hospitalized Adult Patients with COVID-19 from the Randomized, Placebo-Controlled MOVe-OUT Trial

INTRODUCTION

The randomized, placebo-controlled, double-blind MOVe-OUT trial demonstrated molnupiravir (800 mg every 12 h for 5 days) as safe and effective for outpatient treatment of mild-to-moderate COVID-19, significantly reducing the risk of hospitalization/death in high-risk adults. At the time of that report, virologic assessments from the trial were partially incomplete as a result of their time-intensive nature. Here we present final results from all prespecified virology endpoints in MOVe-OUT based on the full trial dataset.

METHODS

Nasopharyngeal swabs were collected at baseline (day 1, prior to first dose) and days 3, 5 (end-of-treatment visit), 10, 15, and 29. From these samples, change from baseline in SARS-CoV-2 RNA titers (determined by quantitative PCR), detection of infectious SARS-CoV-2 (by plaque assay), and SARS-CoV-2 viral error induction (determined by whole genome next-generation sequencing) were assessed as exploratory endpoints.

RESULTS

Molnupiravir was associated with greater mean reductions from baseline in SARS-CoV-2 RNA than placebo (including 50% relative reduction at end-of-treatment) through day 10. Among participants with infectious virus detected at baseline (n = 96 molnupiravir, n = 97 placebo) and evaluable post-baseline samples, no molnupiravir-treated participant had infectious SARS-CoV-2 by day 3, whereas infectious virus was recovered from 21% of placebo-arm participants on day 3 and 2% at end-of-treatment. Consistent with molnupiravir's mechanism of action, sequence analysis demonstrated that molnupiravir was associated with an increased number of low-frequency transition errors randomly distributed across the SARS-CoV-2 RNA genome compared with placebo (median 143.5 molnupiravir, 15 placebo), while transversion errors were infrequent overall (median 2 in both arms). Outcomes were consistent regardless of baseline SARS-CoV-2 clade, presence of SARS-CoV-2-specific immune response, or viral load.

CONCLUSIONS

A 5-day course of orally administered molnupiravir demonstrated a consistently greater virologic effect than placebo, including rapidly eliminating infectious SARS-CoV-2, in high-risk outpatients with mild-to-moderate COVID-19.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04575597.

Inhibitors of dihydroorotate dehydrogenase cooperate with Molnupiravir and N4-hydroxycytidine to suppress SARS-CoV-2 replication

The nucleoside analog N4-hydroxycytidine (NHC) is the active metabolite of the prodrug molnupiravir, which has been approved for the treatment of COVID-19. SARS-CoV-2 incorporates NHC into its RNA, resulting in defective virus genomes. Likewise, inhibitors of dihydroorotate dehydrogenase (DHODH) reduce virus yield upon infection, by suppressing the cellular synthesis of pyrimidines. Here, we show that NHC and DHODH inhibitors strongly synergize in the inhibition of SARS-CoV-2 replication in vitro. We propose that the lack of available pyrimidine nucleotides upon DHODH inhibition increases the incorporation of NHC into nascent viral RNA. This concept is supported by the rescue of virus replication upon addition of pyrimidine nucleosides to the media. DHODH inhibitors increased the antiviral efficiency of molnupiravir not only in organoids of human lung, but also in Syrian Gold hamsters and in K18-hACE2 mice. Combining molnupiravir with DHODH inhibitors may thus improve available therapy options for COVID-19.

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Molnupiravir and DHODH inhibitors are approved drugs, facilitating clinical testing

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The combination may allow lower drug doses to decrease possible toxic effects

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Inhibitors of nucleotide biosynthesis may boost antiviral nucleoside analogs

Comprehensive review on molnupiravir in COVID-19: a novel promising antiviral to combat the pandemic

Despite the progress in the management of COVID-19, effective oral antiviral agents are still lacking. In the present review, the potential beneficial effects of molnupiravir in the management of COVID-19 are discussed. A literature search in Google Scholar, Scopus, PubMed and clinicaltrials.gov for the relevant articles regarding the pharmacokinetics, pharmacodynamics and clinical trials of molnupiravir in the management of COVID-19 is conducted. Most of the preclinical studies and available clinical trials showed a favorable short-term safety profile of molnupiravir; however, given its possible genotoxic effects, further trials are required to confirm the long-term efficacy and safety of molnupiravir in patients with COVID-19.

Molnupiravir in COVID-19: A Scoping Review

BACKGROUND

COVID-19, first detected in Wuhan, China, has evolved into a lifethreatening pandemic spread across six continents, with the global case count being more than 243 million, and mortality over 4.95 million, along with causing significant morbidity. It has initiated an era of research on repurposed drugs such as hydroxychloroquine, lopinavir/ritonavir, corticosteroids, remedesivir, ivermectin, alongside selective antivirals to treat or prevent COVID- 19. Molnupiravir is an orally available emerging antiviral drug considered highly promising for COVID-19.

METHODS AND RESULTS

We have performed a scoping review for the use of molnupiravir against SARS-CoV-2 and COVID-19. It acts by inhibiting RNA-dependent RNA polymerase (RdRp), and exhibits broad-spectrum antiviral activity. Preclinical studies have evaluated the therapeutic efficacy as well as prophylactic activity of molnupiravir against SARS CoV-2 in various animal models that include ferrets, hamsters, mice, immunodeficient mice implanted with human lung tissue and cell cultures, in various doses ranging from 5-300 mg/kg, and results have been encouraging. Initial evidence of safety and efficacy from early phase clinical studies has been encouraging too, and recent results from a large phase 3 global trial have shown significant benefits among symptomatic outpatients. Other late-phase clinical trials are still underway with the aim of establishing molnulpiravir as a therapeutic option for COVID-19, particularly for non-hospitalized patients.

CONCLUSION AND RELEVANCE

On the basis of the limited evidence available as of now, molnupiravir could prove to be a promising oral therapy, worthy of further exploration of its utility for both treatment and prevention of COVID-19 in humans. Elaborate clinical evaluation is further warranted to confirm whether the results are replicable to the clinical scenario among outpatients to reduce the chance of progression to more severe disease.

Molnupiravir: A new candidate for COVID-19 treatment

The novel coronavirus disease 2019 (COVID‐19) emerged in late December 2019 in china and has rapidly spread to many countries around the world. The effective pharmacotherapy can reduce the mortality of COVID‐19. Antiviral medications are the candidate therapies for the management of COVID‐19. Molnupiravir is an antiviral drug with anti‐RNA polymerase activity and currently is under investigation for the treatment of patients with COVID‐19. This review focuses on summarizing published literature for the mechanism of action, safety, efficacy, and clinical trials of molnupiravir in the treatment of COVID‐19 patients.

Molnupiravir in COVID-19: A systematic review of literature

BACKGROUND AND AIMS

Molnupiravir is a newer oral antiviral drug that has recently been tested in COVID-19. We aim to conduct a systematic review of literature to find out the efficacy and safety of molnupiravir in patients with COVID-19.

METHODS

We systematically searched the electronic database of PubMed, MedRxiv and Google Scholar from inception until October 15, 2021, using MeSH keywords. Ongoing trials of molnupiravir in COVID-19 were additionally searched from the ClinicalTrials.Gov and ctri.nic.in/Clinicaltrials. We retrieved all the available granular details of phase 1 to 3 studies of molnupiravir in COVID-19. Subsequently we reviewed the results narratively.

RESULTS

Two phase 1 double-blind, randomized, placebo-controlled (DBRPC) studies of molnupiravir showed that 1600 mg daily dose is safe and tolerable, without any serious adverse events up to 5.5 days. One phase 2 DBPRC study found significantly lower time to clearance (RNA negativity) with molnupiravir 800 mg twice daily compared to the placebo (log-rank p value = 0.013) in mild to moderate COVID-19. Interim report of one phase 3 DBRPC study in non-hospitalized COVID-19 found a significant reduction in the risk of hospital admission or death by 50% (p = 0.0012). However, no significant benefit was observed with molnupiravir in the later stage of moderate to severe COVID-19.

CONCLUSION

Molnupiravir is first oral antiviral drug to demonstrate a significant benefit in reducing hospitalization or death in mild COVID-19 and could be an important weapon in the battle against SARS-CoV-2. However, its role in moderate to severe COVID-19 is questionable and more studies are needed.

Discovery, Development, and Patent Trends on Molnupiravir: A Prospective Oral Treatment for COVID-19

The COVID-19 pandemic needs no introduction at present. Only a few treatments are available for this disease, including remdesivir and favipiravir. Accordingly, the pharmaceutical industry is striving to develop new treatments for COVID-19. Molnupiravir, an orally active RdRp inhibitor, is in a phase 3 clinical trial against COVID-19. The objective of this review article is to enlighten the researchers working on COVID-19 about the discovery, recent developments, and patents related to molnupiravir. Molnupiravir was originally developed for the treatment of influenza at Emory University, USA. However, this drug has also demonstrated activity against a variety of viruses, including SARS-CoV-2. Now it is being jointly developed by Emory University, Ridgeback Biotherapeutics, and Merck to treat COVID-19. The published clinical data indicate a good safety profile, tolerability, and oral bioavailability of molnupiravir in humans. The patient-compliant oral dosage form of molnupiravir may hit the market in the first or second quarter of 2022. The patent data of molnupiravir revealed its granted compound patent and process-related patent applications. We also anticipate patent filing related to oral dosage forms, inhalers, and a combination of molnupiravir with marketed drugs like remdesivir, favipiravir, and baricitinib. The current pandemic demands a patient compliant, safe, tolerable, and orally effective COVID-19 treatment. The authors believe that molnupiravir meets these requirements and is a breakthrough COVID-19 treatment.