Hydroxychloroquine proved ineffective against virus in trial

Hydroxychloroquine did not prevent healthy people exposed to COVID-19 from getting the disease caused by the coronavirus, according to a study being published Wednesday in the New England Journal of Medicine.

The study is the first randomized clinical trial that tested the antimalarial drug, touted by President Donald Trump, as a preventive measure. It showed that hydroxychloroquine was no more effective than a placebo — in this case, a vitamin — in protecting people exposed to COVID-19.

“As we say in Tennessee, ‘That dog won’t hunt’ — it didn’t work,” said William Schaffner, professor of preventive medicine and infectious diseases at Vanderbilt University Medical Center. Dr. Schaffner, who was not involved in the trial, praised it as “rigorously done.”

The results were the latest development on a highly charged medical and political issue — the efficacy of hydroxychloroquine in combating COVID-19. Mr. Trump has repeatedly touted the drug as a “game changer” for COVID19 and recently said he took it for several days. But federal regulators have said it should be used only for hospitalized patients or in clinical trials because of possible side effects, including serious heartrhythm issues.

Researchers at the University of Minnesota Medical School launched the trial in mid-March. They enrolled more than 800 adults in the United States and Canada who were exposed to someone with COVID-19 because of their jobs as health care workers or first responders, or because they lived with someone with the disease. The study was a randomized placebo-controlled trial and was double-blinded, meaning neither the participants nor the researchers knew what the participants received. Such a study is considered the gold standard for clinical trials.

The prevention trial released Wednesday showed 40% of the participants who took the drug developed side effects that weren’t serious — mostly nausea, upset stomach and diarrhea. The study found no serious side effects or cardiac complications, the researchers said.

Its findings reinforced previous studies showing the drug doesn’t provide benefit against COVID-19. “It’s not surprising given that there has not been efficacy established for this drug in any meaningful way.” said Eric Topol, director of the Scripps Research Translational Institute in San Diego. “It’s not a large study, but it extends the spectrum from the most severely ill patients to mildly ill and now preventive.”

Jeanne Marrazzo, an infectious disease expert at the University of Alabama at Birmingham, said the results “should provide a very big nail in the coffin” for the idea that hydroxychloroquine can help prevent COVID-19.

David Boulware, an infectious disease specialist at the University of Minnesota and senior investigator of the study, said he launched the trial because hydroxychloroquine had shown activity in a lab setting against the coronavirus.

About two-thirds of the trial participants were health care workers and the rest were a mix of other people exposed to someone with COVID-19, he said. They were given either hydroxychloroquine or a placebo for five days and then followed for two weeks to see who developed the disease.