An Australian research group has shown that the anti-parasitic drug ivermectin inhibits integrase protein import of COVID-19, according to a report published in Antiviral Research.
Ivermectin has previously been identified as an inhibitor of interaction between HIV-1 integrase protein (IN) and the importin (IMP) α/β1 heterodimer responsible for IN nuclear import.
In vitro cells were infected with COVID-19 isolate Australia/VIC01/2020 for two hours, followed by the addition of 5αM of ivermectin. At 24 hours, a 93% reduction in viral RNA was present in the supernatant of samples treated with Ivermectin that controls.
Similarly, a 99.8 per cent reduction in cell-associated viral RNA was seen at 48 hours, indicating unreleased and unpackaged virions. No further viral replication was observed at 72 hours.
The half-maximal inhibitory concentration (IC50) of ivermectin treatment was determined to be approximately 2αM under the same conditions. Reverse transcription-polymerase chain reaction (RT-PCR) using primers for the viral RdRp gene reproduced the results almost identically.
Ivermectin has an established safety profile for human use. This report raises the possibility that ivermectin could be a useful antiviral to limit COVID-19. A critical next step will be to evaluate dosing regimens.