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08 Nov 2023

Could nafamostat, an antiviral drug, help treat COVID-19? ASCOT’s randomised clinical trial reveals all

The Australasian COVID-19 Trial (ASCOT), a study into treatment effectiveness in patients hospitalised with COVID-19, published a new paper in the journal NEJM Evidence presenting the results of their antiviral research.  

As part of the trial, researchers sought to determine whether receipt of an antiviral treatment, Nafamostat mesylate (nafamostat), showed more benefit compared to not receiving it. Nafamostat has been safely used in humans for other conditions, such as pancreatitis, but has not yet been approved for use in COVID-19.

Antiviral treatments may work by blocking the virus from entering human cells, therefore preventing the viruses’ ability to multiply. Laboratory studies have shown that nafamostat may have high antiviral activity, as well as blood thinning properties which may help to treat blood clots associated with COVID-19.

160 participants from Australia, New Zealand and Nepal took part in the ASCOT trial.

Participants who received the nafamostat antiviral had a 93 per cent probability of better outcomes than those not receiving nafamostat. Specifically, those receiving nafamostat were less likely to require ventilator support for their breathing. However, those who received the treatment experienced elevated potassium levels (hyperkalaemia) and high rates of bleeding events compared to those who did not receive the drug.  

Due to declining numbers of patients needing hospital treatment for pneumonia with COVID-19, the trial stopped early, so no prespecified stopping criteria were reached. More participants would have provided more data to inform the certainty of the results.

These results are important as the benefit may be sufficient to change practice if nafamostat were low cost, low risk and easily implemented. But as nafamostat requires a continuous intravenous infusion and has shown increased rates of side effects, the researchers think a higher probability of effectiveness is needed to recommend its use.

Outcomes from this study will add to the current pool of evidence and help inform standard practice to treat COVID-19 in non-critically ill patients. The data generated will also be combined with data from other trials to provide a broader picture of the role for nafamostat and related drugs for COVID-19.

This article was adapted from an article first published by ASCOT.

ASCOT is a clinical trial that generates clinical evidence about treatment for COVID-19 to reduce mortality or the need for mechanical ventilation in patients hospitalised with COVID-19 but who are not critically ill.

ASCOT is supported by the Australian Partnership for Preparedness Research on Infectious Disease Emergencies (APPRISE), the BHP Foundation, the Health Research Council (HRC) of New Zealand, the Hospital Research Foundation, the Macquarie Group Foundation, the Minderoo Foundation, the Pratt Foundation, the Royal Brisbane and Women’s Hospital Foundation, the Common Good (the Prince Charles Hospital Foundation), Wesley Medical Research, Chong Kun Dang Pharmaceutical Corp, the NSW Office for Health and Medical Research, the Medical Research Future Fund (MRFF) and the Russell and Womersley Foundation.