First: It seems that several major studies, including one in The Lancet suggesting that the drug is actually harmful, were based on rather questionable data. The Guardian has the details: “The US-based company Surgisphere, whose handful of employees appear to include a science fiction writer and an adult-content model, has provided data for multiple studies on Covid-19 co-authored by its chief executive, but has so far failed to adequately explain its data or methodology.” The company has a minimal online presence, and the “get in touch” function on its website doesn’t even work, yet it provided data it claimed to get from “more than a thousand hospitals worldwide.” These revelations follow concerns aired elsewhere that the data seemed fishy.
Second, though, a randomized trial found that the drug didn’t measurably help to prevent COVID-19 when given to individuals who’d been exposed to infected people. From the New York Times:
Conducted in the United States and Canada, this trial was the first to test whether the drug could prevent illness in people who have been exposed to the coronavirus. This type of study, in which patients are picked at random to receive either an experimental treatment or a placebo, is considered the most reliable way to measure the safety and effectiveness of a drug. The participants were health care workers and people who had been exposed at home to ill spouses, partners or parents.
“The take-home message for the general public is that if you’re exposed to someone with Covid-19, hydroxychloroquine is not an effective post-exposure, preventive therapy,” the lead author of the study, Dr. David R. Boulware, from the University of Minnesota, said in an interview.
The drug could still be effective against COVID-19 in other situations, and there are other trials in the works. And there are some weaknesses to the study itself:
Not all the participants could be tested for the virus, because when the study was being conducted, there was still a shortage of test kits.
There was no meaningful difference between the placebo group and those who took the drug. Among those taking hydroxychloroquine, 49 of 414, or 11.8 percent, became ill. In the placebo group, 58 or 407, or 14.3 percent, became ill. Analyzed statistically, the difference between those rates was not significant.
In other words, they couldn’t test everyone to make sure their illnesses were COVID-19, and people who got the drug were about 17 percent less likely to become “ill” — a difference that wasn’t statistically significant because the study was so small. But there’s no denying this is disappointing news.