Chloroquine and hydroxychloroquine fail again in new studies

Two studies published on Wednesday in the journal Nature add to evidence that the malaria drugs chloroquine and hydroxychloroquine are not helpful against coronavirus disease 2019 (COVID-19). 

One study found no notable antiviral effect of hydroxychloroquine against COVID-19 in primates.

The other found no effect of chloroquine in infected human lung cells in test tubes.

Hydroxychloroquine has been touted by US President Donald Trump as a COVID-19 treatment and the two related drugs have been investigated for their potential to treat the illness caused by the novel coronavirus in more than 80 registered clinical trials.

But more and more data from clinical trials suggest the drugs are ineffective for either treating or preventing the disease.

In the Nature study of monkeys with coronavirus infections, hydroxychloroquine "showed no substantial antiviral activity, regardless of the timing of treatment initiation, either before infection, soon after infection or late after infection," the researchers said in a news release. -- Reuters