The most prescribed oral antiviral in the country is now regarded as a ‘last resort’, although it can still be accessed via the PBS.
Vulnerable covid patients should no longer be routinely treated with molnupiravir (Lagevrio), according to a recent change in guidance from the National COVID-19 Clinical Evidence Taskforce – a move which appears to have divided some experts.
The change was prompted by data from a large-scale UK trial of 25,000 covid patients, recently published in Social Science Research Network, examining the impact of molnupiravir against standard care.
However, Australia’s acting chief medical officer, Professor Michael Kidd, has disputed the Taskforce’s updated recommendations for prescribing molnupiravir and urged patients to continue asking their doctors for it.
In a statement published on the Department of Health and Aged Care’s website, Professor Kidd emphasised the efficacy of the antiviral in helping those most vulnerable to covid-19 avoid severe illness and death, referring to it as a “gamechanger” alongside nirmarelvir and ritonavir (Paxlovid).
“Australia’s real-world experience is that the two covid-19 oral antiviral treatments approved for local use are both highly effective at protecting older Australians – a key at-risk population group – from hospitalisation and death,” he said.
The UK trial findings showed that the antiviral did not reduce rates of hospitalisation or death in high-risk vaccinated adults, despite producing faster recovery times and a reduced viral load.
As a result, the Taskforce updated its recommendations to reflect the “high certainty evidence” that molnupiravir does not affect hospitalisation or death in mild covid patients who have received more than one vaccine, and who have one or more risk factors for disease progression.
The Taskforce It said the trial’s data supported nirmaltrelvir plus ritonavir (Paxlovid) and remdesivir as the preferred antivirals for treating mild covid, in line with the Taskforce’s existing advice.
“Current evidence provides greater certainty of clinical benefit for other antiviral agents in the broader population; therefore use of these other antivirals agents rather than molnupiravir is preferred,” wrote the authors of the Taskforce’s rationale for changing the guidelines.
“However, there may be specific circumstances for the highest risk patients, where all other treatment options are contraindicated or inappropriate, in which non-routine use of molnupiravir might be considered, in consultation with specialist clinicians where necessary.”
Arguing that the participants in the UK study behind the change were generally younger than those eligible for oral antivirals in Australia, Professor Kidd claimed that the findings were inaccurate for most Australian patients.
In his statement, Professor Kidd cited results from a Victorian study, yet to be published or peer-reviewed, which showed that both Lagevrio and Paxlovid reduced the risks of hospitalisation and death in over 27,000 participants aged 70 or older.
Alongside the study, whose findings he insisted were “applicable nationwide,” Professor Kidd also referred to a statement from the Pharmaceutical Benefits Advisory Committee (PBAC), highlighting Lagevrio as a suitable alternative for patients unable to take Paxlovid.
“It is very important Australians, particularly older Australians and those who are immunocompromised, talk to their doctors about their eligibility for COVID-19 antiviral treatments – and if eligible, make sure they can access and start their treatments as quickly as possible after a positive COVID-19 test result,” he said.
The Taskforce has also published a prescribing guide for nirmaltrelvir plus ritonavir (Paxlovid) on its website.
According to the most recent covid-19 update from the Department of Health and Aged Care, molnupiravir has been prescribed at more than three times the rate of Paxlovid since being listed on the PBS earlier this year.
Around 329,000 molnupiravir prescriptions have been dispensed as of 2 December, compared to 96,000 for Paxlovid.
First published as Molnupiravir no good for mild covid. Updated to include a statement from acting CMO Professor Michael Kidd
