Singapore inks deal for antiviral pill to treat Covid-19 and its variants

SINGAPORE - The Republic has inked a supply and purchase agreement for an antiviral pill to treat Covid-19 that is said to be effective against all known variants of the virus, including the Delta variant.

The drug was developed by pharmaceutical firm Merck in the United States and Canada, together with Miami-based Ridgeback Biotherapeutics. Merck is known as MSD elsewhere in the world. 

The drug will be available in Singapore once it has received authorisation and approval for use, said MSD in an announcement on Wednesday (Oct 6).

The Straits Times has contacted the Ministry of Health for comment.

Known as molnupiravir, the drug comes in pill form and targets an enzyme that the virus needs to make copies of itself, by introducing errors into its genetic code.

This particular enzyme - known as the viral polymerase - is conserved across different variants, making molnupiravir effective across the Gamma, Delta and Mu variants.

Data from clinical trials suggests the drug is most effective when given early in the course of infection, said MSD.

Interim trial results last Friday showed the drug may reduce the chance of hospitalisation or death by half for patients who are at risk of severe disease.

The companies plan to seek US emergency use authorisation for the pill as soon as possible, and to submit applications to regulatory agencies worldwide.

"As the pandemic continues to evolve and surges are being reported in many places around the world, we are hopeful that we can make a meaningful impact on the pandemic through development of an effective oral antiviral that can be taken in the earlier stages of disease, outside of hospitalised settings to limit disease progression," said Dr Nick Kartsonis, senior vice-president, vaccines and infectious diseases, clinical research, MSD Research Laboratories.

So far, Australia has entered advance supply agreements with MSD to purchase 300,000 courses of the drug.

Other places such as South Korea, Thailand, Taiwan and Malaysia are also in talks with the company to purchase the drug.

Commenting on the drug, infectious diseases specialist Leong Hoe Nam of the Rophi Clinic at Mount Elizabeth Novena said: "It is a useful adjunct to the high vaccine coverage in Singapore. Very significantly, we can arm our front-line doctors with the oral medication that may make a difference at the point of diagnosis. This may shift treatment from hospitals to general practitioners and polyclinics as Singapore pivots towards endemic living with Covid-19."

Dr Shawn Vasoo, clinical director of the National Centre for Infectious Diseases, told The Straits Times that it is not so clear at this point how molnupiravir might compare with other therapies for mild-to-moderate Covid-19, such as antibody treatment or remdesivir, and how clinicians may decide to choose one drug over the other. 

“Certainly, oral medication has greater convenience over intravenous medications, but such data is lacking at this point. This may be a potential area for further study,” he added.

Currently, molnupiravir is being evaluated as a Covid-19 treatment and a preventive drug.

The global phase three treatment trial enrolled Covid-19 patients with mild to moderate Covid-19 who had symptoms for up to five days.

All of them had at least one risk factor associated with poor disease outcomes, including obesity, diabetes, heart disease and those aged above 60.

The trial results are expected early next month, said MSD.

In anticipation of the results, MSD expects to produce 10 million courses of treatment by the end of the year, with more doses to be produced next year.

The second trial, looking at molnupiravir as a preventative drug, will study the efficacy and safety of administering the drug to prevent the spread of Covid-19 within household settings.

Results are likely to be available in the first half of next year.

Local researchers had in their own study also identified molnupiravir as an effective drug against the original Sars-CoV-2 virus, as well as the Beta and Delta variants.

A team led by Professor Dean Ho, director of the National University of Singapore's Institute for Digital Medicine, together with the DSO National Laboratories, found that molnupiravir, combined with baricitinib, an anti-inflammatory drug, could be a possible combination for Covid-19 treatment.

Prof Ho had told ST in August that both drugs come in a pill format and can therefore be administered to those with mild illness who are recovering at home, or in a community care setting.