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Molnupiravir

Generic Name
Molnupiravir
Drug Type
Small Molecule
Chemical Formula
C13H19N3O7
CAS Number
2349386-89-4
Unique Ingredient Identifier
YA84KI1VEW
Background

Molnupiravir (EIDD-2801, MK-4482) is the isopropylester prodrug of N4-hydroxycytidine. With improved oral bioavailability in non-human primates, it is hydrolyzed in vivo, and distributes into tissues where it becomes the active 5’-triphosphate form. The active drug incorporates into the genome of RNA viruses, leading to an accumulation of mutations known as viral error catastrophe. Recent studies have shown molnupiravir inhibits replication of human and bat coronaviruses, including SARS-CoV-2, in mice and human airway epithelial cells. A remdesivir resistant mutant mouse hepatitis virus has also been shown to have increased sensitivity to N4-hydroxycytidine.

Molnupiravir was granted approval by the UK's Medicines and Health products Regulatory Agency (MHRA) on 4 November 2021 to prevent severe outcomes such as hospitalization and death due to COVID-19 in adults. Molnupiravir was also granted emergency use authorization by the FDA on December 23, 2021; however, it is not yet fully approved.

Indication

N4-hydroxycytidine and its prodrug molnupiravir are being studied for its activity against a number of viral infections including influenza, MERS-CoV, and SARS-CoV-2.

Molnupiravir is approved in the UK for reducing the risk of hospitalization and death in mild to moderate COVID-19 cases for patients at increased risk of severe disease (eg. with obesity, diabetes mellitus, heart disease, or are over 60 years old).

In the US, molnupiravir is authorized for emergency use for the treatment of high-risk adults With mild to moderate COVID-19.

Associated Conditions
Death, Hospitalizations
Clinical Trials
Related News

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Merck and Ridgeback Initiate Phase 3 Trial of Molnupiravir for High-Risk COVID-19 Adults

• Merck and Ridgeback Biotherapeutics have commenced a Phase 3 trial (MOVe-NOW) to assess molnupiravir's efficacy in high-risk, non-hospitalized adults with COVID-19. • The trial will evaluate a new formulation of molnupiravir, administered as two 400-mg tablets twice daily for five days, compared to placebo. • The study aims to enroll approximately 3,082 participants globally who cannot receive nirmatrelvir/ritonavir due to various contraindications. • Primary endpoints include hospitalization, death, or COVID-19-related medical visits through day 29, with extended follow-up for long-term COVID-19 effects.

PANORAMIC Trial Launches to Evaluate Oral Antivirals for Early COVID-19 Treatment

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FDA Updates Pemgarda EUA Due to Emerging SARS-CoV-2 Variants

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