Vaccine Info

Molnupiravir (MK-4482, EIDD-2801) Antiviral

Last Reviewed
January 10, 2021

Molnupiravir (MK-4482, EIDD-2801) Antiviral Description

Molnupiravir (MK-4482/EIDD-2801) is an experimental oral antiviral drug originally developed for the treatment of influenza. MK-4482/EIDD-2801 consists of the nucleoside analogue N4-hydroxycytidine (NHC). Molnupiravir has been evaluated against coronaviruses (CoVs), including SARS-1, MERS-CoV, and SARS-CoV-2.

The drug was originally developed at Emory University by its drug innovation company, Drug Innovation Ventures at Emory (DRIVE). It was later acquired by Ridgeback Biotherapeutics, which has partnered with Merck & Co. to continue developing the antiviral.

A study published on April 29, 2020, found the potency of NHC/EIDD-2801 against multiple CoVs, and oral bioavailability highlights its potential utility as an effective antiviral against SARS-CoV-2 and other future zoonotic CoVs.

On June 19, 2020, Miami-based Ridgeback Biotherapeutics announced the launch of two Phase 2 clinical trials to test the efficacy of EIDD-2801 as an anti-viral treatment for COVID-19. The Phase 2a randomized, placebo-controlled, double-blinded clinical trial of EIDD-2801 in adult men and women who have tested positive for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection within 144 hours of polymerase chain reaction confirmation and are hospitalized with a diagnosis of COVID-19. Rapid enrollment and treatment will be initiated such that the first dose of EIDD-2801 or placebo will be administered as soon as possible and within 7 days of onset of symptoms. Last Update Posted: January 5, 2021.

A study published by the journal Nature on December 3, 2020, identified oral MK-4482/EIDD-2801 as a promising antiviral countermeasure to break SARS-CoV-2 community transmission chains.

Ridgeback Biopharmaceuticals was co-founded by CEO Wendy Holman and Dr. Wayne Holman, a scientific advisor to the company, focusing on developing anti-viral medications for diseases with epidemic and pandemic risk.

Molnupiravir (MK-4482, EIDD-2801) Antiviral Indication

Molnupiravir (MK-4482/EIDD-2801) antiviral is indicated to mitigate SARS-CoV-2 infection and block transmission, preventing COVID-19 disease.

Molnupiravir (MK-4482, EIDD-2801) Antiviral News

December 21, 2020 - Results of the research by scientists at the Institute of Biomedical Sciences, Georgia State University, have been published in Nature Microbiology. And Indian researchers plan to apply to the drug regulator to conduct human trials with the drug. The antiviral drug Molnupiravir, or MK-4482/EIDD-2801, is taken orally. Molnupiravir is being developed by the biotechnology firm Ridgeback Biotherapeutics in collaboration with pharmaceutical firm Merck.

December 5, 2020 - Researchers in the Institute for Biomedical Sciences at Georgia State University, led by Dr. Richard Plemper, found treating a SARS-CoV-2 infection with a new antiviral drug, MK-4482/EIDD-2801 or Molnupiravir, completely suppresses virus transmission within 24 hours.

December 3, 2020 - Study: Therapeutically administered ribonucleoside analogue MK-4482/EIDD-2801 blocks SARS-CoV-2 transmission in ferrets. This study identified oral MK-4482/EIDD-2801 as a promising antiviral countermeasure to break SARS-CoV-2 community transmission chains.

July 7, 2020 - Ridgeback Biotherapeutics announced the start of enrollment in a Phase 2 trial of potential COVID-19 treatment EIDD-2801. The new trial will be conducted using the new COVID-19 drug testing platform, AGILE. AGILE will test multiple potential therapeutics, and EIDD-2801 was selected to be the first oral anti-viral to be studied in the AGILE platform.

July 1, 2020 - Miami based Ridgeback Biotherapeutics LP, announced an agreement with Merck that the U.S. Federal Trade Commission granted early termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act. All closing requirements have been completed for the previously announced partnership transaction to advance the development of EIDD-2801, an investigational orally-available antiviral agent currently in early clinical development for the treatment of patients with COVID-19.

August 1, 2020 - Merck & Co. plans to begin two large clinical trials in September of an experimental oral antiviral therapy for Covid-19, pushing ahead with efforts to bring another treatment option to the market. There is a “profound medical need for an orally active treatment,” Roger Perlmutter, the pharmaceutical giant’s top scientist, said Friday on Merck’s earnings conference call. The therapy, known as MK-4482.

Molnupiravir (MK-4482, EIDD-2801) Antiviral Clinical Trials

MK-4482/EIDD-2801 is currently being tested in various, advanced multi-center clinical trials:

Clinical Trial NCT04405739:  The Safety of Molnupiravir (EIDD-2801) and Its Effect on Viral Shedding of SARS-CoV-2 (END-COVID) - Last Update Posted: January 5, 2021

Phase 2a randomized, placebo-controlled, double-blinded clinical trial of EIDD-2801 in adult men and women who have tested positive for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection within 48 hours of polymerase chain reaction (PCR) confirmation and are hospitalized with a diagnosis of COVID-19.

Rapid enrollment and treatment will be initiated such that the first dose of EIDD-2801 or placebo will be administered as soon as possible and within 7 days of onset of symptoms.

Stratified randomization of participants will receive remdesivir at enrollment and those who will not receive remdesivir at enrollment.

Estimated Primary Completion Date: February 12, 2021.

Clinical Trial NCT04405570:  A Safety, Tolerability, and Efficacy of Molnupiravir (EIDD-2801) to Eliminate Infectious Virus Detection in Persons With COVID-19

This is a phase IIa, double-blind, placebo-controlled, randomized trial designed to compare the safety, tolerability, and antiviral activity of EIDD-2801 versus placebo as measured by infectious virus detection symptomatic adult outpatients with COVID-19.

The study is a multicenter trial that will be conducted in the United States.

In this study, up to approximately 108 participants will be randomized to receive EIDD-2801 or Placebo orally twice a day (BID) for 5 days. The study may enroll up to 5 parts with subsequent doses that may be higher or lower than doses studied in previous cohorts and will be doses that have been studied for safety in a Phase 1 study. Doses will be chosen based on emerging virology and safety data from this and ongoing studies.

Clinical Trial NCT04575584:  Efficacy and Safety of Molnupiravir (MK-4482) in Hospitalized Adult Participants With COVID-19 (MK-4482-001)

This study evaluates the safety, tolerability, and efficacy of molnupiravir (MK-4482) compared to placebo. The primary hypothesis is that molnupiravir is superior to placebo as assessed by the rate of sustained recovery through Day 29.

Clinical Trial NCT04575597: Efficacy and Safety of Molnupiravir (MK-4482) in Non-Hospitalized Adult Participants With COVID-19 (MK-4482-002)

This study evaluates the safety, tolerability, and efficacy of molnupiravir (MK-4482) compared to placebo. The primary hypothesis is that molnupiravir is superior to placebo as assessed by the percentage of hospitalized and/or dead participants through Day 29.