Drug touted by Trump ineffective

U.S.-Canada study says hydroxychloroquine doesn’t protect against COVID-19

OTTAWA— A new joint CanadaU.S. scientific study of hydroxychloroquine says the drug that U.S. President Donald Trump promotes as a preventive medication does not protect people who’ve been exposed to the coronavirus from developing the COVID-19 disease.

It is the first large, randomized, double-blind, placebocontrolled clinical trial of the drug to be published in a major peer-reviewed medical journal, the New England Journal of Medicine, and is the kind of “gold-standard” trial that gives reliable scientific results, said one of its Canadian researchers, Dr. Emily McDonald, of McGill University Health Centre.

The study published Wednesday comes on the same day as the Journal and Britain’s The Lancet issued major expressions of concern about separate earlier studies they had published containing data that raised major concerns about the safety of the drug.

The politics around use of hydroxychloroquine have been inflamed by Trump touting its benefits and claiming he was taking it to protect himself, while others have warned, without clear proof, that it is dangerous.

The latest study used participants in the U.S., Quebec, Manitoba and Alberta and shows no preventive benefit came from using hydroxychloroquine as a prophylaxis for people who had a high-risk exposure to the virus, according to a release by the McGill research team.

That suggests Trump is wrong to claim its use will prevent the disease. However, the study also showed the medication had no significant side effects, such as cardiac arrhythmia or irregular heartbeat, that many had feared after less-rigorous studies suggested hydroxychloroquine was unsafe and could even cause death in hospitalized patients.

“It really is a cautionary tale about the rush to publish and the rush to provide timely answers that can impact immediately on care, balanced with the scientific rigour that we’ve come to expect in modern-day research,” said Macdonald.

“It’s incredibly important that we complete randomized controlled trials so that we have the best available evidence for how to prevent the spread of COVID-19,” she said.

The latest study showed only minor side effects, like nausea and abdominal discomfort, in patients taking the medication compared to those taking a placebo — a harmless substitute used as a control in such tests.

That’s encouraging news for scientists whose studies were paused or suspended last week, based on early observational studies. The World Health Organization had ordered its global “Solidarity” trial into hydroxychloroquine paused while it reviewed safety data, and other countries followed suit.

“It is clear to me that we can continue to enrol patients in early-treatment trials in the community because it is the same type of population as in the post-exposure study,” she said. “So the question now that needs to be answered is, is it effective for early treatment.”

Dr. Ryan Zarychanski, who led the University of Manitoba’s research efforts in the trial, said in a statement the study’s results “set politics aside and provide unbiased evidence to guide practice in the prevention of COVID-19.”

The Canada-U.S. trial gave the drug and a placebo to a group that included 821 asymptomatic adults in the U.S., Quebec, Manitoba and Alberta, most of whom (719) had a high-risk exposure to a confirmed COVID-19 case. The others had moderate exposures.

Overall, 107 or 13 per cent of participants developed COVID-19 over two weeks of followup. Among those who received hydroxychloroquine, 49 developed the disease versus 58 in the control group that received a placebo. Two patients, one in each group, were hospitalized. No deaths occurred.

The participants were largely healthy people, with an average age of about 40, and mainly health-care workers who had been missing a piece of their personal protective equipment while in close quarters for longer than 10 minutes with someone who is infected. Within four days of exposure to the virus, participants in the study got either a dose of the drug or a placebo over five days.

McDonald said a separate study she is involved with is studying whether there is any benefit to the use of hydroxychloroquine as an early treatment of patients who have had a positive COVID-19 diagnosis but are well enough to stay in their homes in isolation.

“It’s incredibly important that we complete randomized controlled trials.”

DR. EMILY MCDONALD MCGILL RESEARCHER