Explained: What is Molnupiravir, the COVID ‘game-changer’?

The United Kingdom approved Molnupiravir, the COVID-19 antiviral pill, jointly developed by US-based Merck and Ridgeback Biotherapeutics, to treat the disease.

The drug, as suggested by Britain’s Medicines and Healthcare products Regulatory Agency (MHRA), is supposed to be administered as soon as a patient tests positive for COVID and within five days of the onset of symptoms.

Touted to be a game changer for high-risk and immunosuppressed individuals, Molnupiravir is said to reduce the risk of hospitalization and death in COVID patients by half.

Here’s all you need to know about the drug:

What is Molnupiravir and how it works?

It is the first antiviral medication for COVID-19 which can be taken as a pill.

The drug, just like remdesivir, is a nucleoside analogue that causes viruses to make errors while copying their own RNA. So, when SARS-CoV-2 invades a cell, it tries to duplicate the cell’s RNA genome to form new viruses. Molnupiravir acts by incorporating into the RNA strands and changing its configuration. Because of this, the RNA strands become faulty blueprints for the next round of viral genomes. The viral population then tends to collapse after enough mutations happen. This process is called lethal mutagenesis.

Also read: Gene common in South Asians may double risk of COVID death: Study

Molnupiravir was initially invented by scientists at Emory University to treat influenza virus.

What the trials said?

Phase 3 trials of the drug shows that it “significantly reduced the risk of hospitalization or death… in a risk, non-hospitalised adult patient with mild-to-moderate COVID-19.”

In the trials which involved 775 volunteers, half the people who were administered the drug within five days of showing COVID symptoms showed half the rate of hospitalization and death, as opposed to those who were given a placebo.

Merck said around 7.3 per cent of individuals who were given molnupiravir were either hospitalized or died by Day 29 compared to 14.1 per cent of those receiving placebo. It said no deaths were reported in patients who were given molnupiravir compared to eight deaths in patients who received placebo.

Quoting pre-clinical and clinical data, Merck has said that the drug has shown efficiency against COVID variants like Delta, Mu and Gamma.

However, 50 per cent efficacy also means 50 per cent inefficacy on the part of the drug.

It should be also noted that a week after Merck claimed about Molnupiravir’s 50 per cent efficiacy, two Indian drug-makers sought to conclude their trials of the same drug, stating that the drugs didn’t show any benefits on patients with moderate COVID-19.

Who should be given Molnupiravir?

Four pills of Molnupiravir should be given twice a day to vulnerable patients who have been recently diagnosed with COVID-19.

To ensure efficacy, the drug should be given within five days of a patient testing positive for COVID-19.

The MHRA has authorized the tablet for use in patients with mild to moderate COVID and at least one risk factor for developing severe illness like old age, heart disease, diabetes or obesity.

Also read: WHO’s grim warning for Europe: Half a million COVID deaths likely by Feb

Britain has already made a deal to purchase 480,000 courses of the drug in the first delivery in November.

Merck said it is expecting to produce 10 million courses of the drug by the end of 2021 and manufacture at least 20 million in 2022.