Washington University researchers are launching an international study to test whether the drug chloroquine can prevent coronavirus infection.
Chloroquine and the closely related hydroxychloroquine have been used for decades for the prevention and treatment of malaria. But researchers are now examining whether the former might also be useful in the global fight against COVID-19. The collaborative team spanning four continents will enroll tens of thousands of health care workers in the clinical trial.
The severity of the coronavirus outbreak has accelerated the drug development process, which usually takes years, said Michael Avidan, a Washington University anesthesiology professor.
“We don’t have the luxury of time with COVID-19,” said Avidan, one of the study leaders. “We need to go from discovery to implementation within weeks to months. Any delay could potentially cost lives.”
For that reason, researchers are examining existing drugs, like chloroquine, that could be swiftly repurposed to prevent or treat COVID-19.
Early evidence suggests chloroquine might block the coronavirus from entering human cells, which it needs to do to replicate. Other lab research has shown chloroquine can prevent the spread of a related coronavirus that causes severe acute respiratory syndrome, or SARS.
“Although I’m optimistic, I’m also a skeptic,” Avidan said. “If you ask, ‘Do I think chloroquine works?’ I’ll say to you, ‘I really hope it does, but I don’t know.’”
Though chloroquine has undergone extensive safety testing as a malaria treatment, it has side effects. In some patients, it causes serious heart rhythm problems — particularly when taken in combination with certain medications, like azithromycin.
Last month, the FDA warned the public that taking hydroxychloroquine and chloroquine for COVID-19 “should be limited to clinical trial settings or for treating certain hospitalized patients.”
The Wash U clinical trial will enroll an estimated 30,000 health care workers in at least 10 countries, including Cameroon, Peru, South Africa and Switzerland. Local health care workers in St. Louis will also be eligible to enroll in the trial. Researchers plan to exclude high-risk participants, including people with heart or kidney disease, as well as those taking certain medications.
Some participants will receive chloroquine at various doses for three months, while one group will receive a placebo.
The research teams will monitor patients for an additional two months to determine if the drug prevents coronavirus infection or reduces the severity of COVID-19. They're also hoping to pinpoint the lowest possible effective dose, said Mary Politi, Wash U professor of surgery and study leader.
“The lower the dose, the less likely the chance of side effects and the more likely it will be widely available if this drug is successful,” Politi said. “Less is more for most things in medicine.”
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