Australia Provisionally Approves Two Oral COVID Treatments, So What Does This Mean?

Australia Provisionally Approves Two Oral COVID Treatments, So What Does This Mean?
Image: Merck via AP

As of yesterday, 92.7 per cent of Australians over the age of 16 are fully vaccinated, with 5.5 million of us having received a third shot. But as this number continues to rise, the Australian government is looking to add another weapon to its COVID-19 armoury, with the TGA provisionally approving two oral treatments.

On Thursday, the Therapeutic Goods Administration (TGA) granted provisional approval to two oral COVID-19 treatments:

  • PAXLOVID (nirmatrelvir + ritonavir) – Pfizer Australia Pty Ltd
  • LAGEVRIO (molnupiravir) – Merck Sharp & Dohme (Australia) Pty Ltd

The Australian government has secured access to 500,000 treatment courses of PAXLOVID, after announcing in October it had secured 300,000 does of LAGEVRIO (molnupiravir). The first deliveries of both medicines are anticipated in the coming weeks, here’s what you should know.

What are nirmatrelvir + ritonavir and molnupiravir?

These pills are oral antiviral medication for treating COVID-19.

LAGEVRIO (molnupiravir) was originally developed to treat influenza. Ridgeback Biotherapeutics and Merck are collaborating on the development of the antiviral.

Patients take four pills of molnupiravir twice a day for five days.

Molnupiravir works by inhibiting replication of the SARS-CoV-2 virus. When you boil it down, molnupiravir works by causing genetic mutations that confuse the virus.

Regarding PAXLOVID, the nirmatrelvir component blocks the activity of a protease enzyme that the coronavirus needs in order to replicate. Nirmatrelvir is administered in combination with low-dose ritonavir to maintain plasma levels of nirmatrelvir for the duration of the treatment.

Who can take them?

Both of these products can be taken by adults with COVID-19 who do not require initiation of oxygen and who are at increased risk of progression to hospitalisation or death.

The TGA says either medicine should be administered as soon as possible after diagnosis of COVID-19 and within five days of the start of symptoms. LAGEVRIO (molnupiravir) is available as capsules, while PAXLOVID comprise separate tablets of nirmatrelvir and ritonavir. In both cases, the medicines are taken twice a day for five days.

Do these pills work?

Both PAXLOVID and LAGEVRIO have received conditional marketing authorisation from the UK Medicines and Healthcare products Regulatory Agency and emergency use authorisation from the U.S. Food and Drug Administration, and PAXLOVID was authorised by Health Canada earlier this week.

The TGA says:

Australians can be confident that the TGA’s review process of both medicines was rigorous. The decision to provisionally approve the medicine was informed by expert advice from the Advisory Committee on Medicines (ACM), an independent committee with expertise in scientific, medical and clinical fields including consumer representation.

According to Merck, molnupiravir ‘significantly’ reduced the risk of hospitalisation or death from COVID in at-risk patients with mild or moderate cases.

Its findings were published following a clinical trial of 775 adult COVID-19 patients.

Interim results found that 29 days after treatment, 7.3 per cent were hospitalised and there was not a single death. 14.1 per cent of those given a placebo in the trial were hospitalised and eight unfortunately passed away.

Are molnupiravir/nirmatrelvir + ritonavir different to sotrovimab?

You might have heard last year that Australia received 15,000 new supplies of a drug called sotrovimab.

Like molnupiravir/nirmatrelvir + ritonavir, sotrovimab helps to protect people against developing severe symptoms. The TGA approved sotrovimab back in August.

Unlike the two pills, sotrovimab requires a single dose to be administered intravenously.

LAGEVRIO (molnupiravir) and PAXLOVID (nirmatrelvir + ritonavir) will mean patients can take a pill at home, instead of visiting a healthcare facility. It’s also way less invasive.

Should I still get the vaccine?

Yes.

LAGEVRIO (molnupiravir) and PAXLOVID (nirmatrelvir + ritonavir) are both treatments. Neither product is intended to be used as a substitute for vaccination against COVID-19. It won’t protect against COVID like the vaccines do, rather it will (hopefully) be there to prevent those with COVID from feeling the full brunt of symptoms.

This article was originally published in October and has been updated to reflect current information.