This wasn’t a randomized clinical trial of the sort that confirmed the efficacy of remdesivir. This was just an observational trial, i.e. doctors at New York-Presbyterian started giving the drug to certain coronavirus patients to see if it would help based on the encouraging small studies out of China and France.

It didn’t work. The result does come with a footnote: Hydroxychloroquine tended to be given to patients who started off sicker than those who didn’t receive the drug, which makes sense under the circumstances. The more desperate someone’s condition is, the more a doctor will be willing to try anything to help them recover. But “widely accepted methods [of analysis] were used to take that into account and still no benefit was seen for the drug,” said the AP of the results. Maybe a clinical trial will show that HCQ has some benefit if administered earlier in the course of the illness.

But the number of discouraging observational studies is growing. A different preliminary study conducted in New York hospitals also found no benefit. Same with a study of patients at VA hospitals, where those who received the drug actually died more often than those who didn’t.

The study published Thursday is the largest to date to investigate the drug, which is approved by the U.S. Food and Drug Administration to treat malaria and certain autoimmune disorders, as a treatment for COVID-19. Dr. Neil Schluger, chief of the division of pulmonary, allergy and critical care medicine at Columbia, and his team studied more than 1,300 patients admitted to New York-Presbyterian Hospital-Columbia University Irving Medical Center for COVID-19. Some received hydroxychloroquine on an off-label basis, a practice that allows doctors to prescribe a drug that has been approved for one disease to treat another — in this case, COVID-19. About 60% of the patients received hydroxychloroquine for about five days. They did not show any lower rate of needing ventilators or a lower risk of dying during the study period compared to people not getting the drug.

“We don’t think at this point, given the totality of evidence, that it is reasonable to routinely give this drug to patients,” says Schluger. “We don’t see the rationale for doing that.” While the study did not randomly assign people to receive the drug or placebo and compare their outcomes, the large number of patients involved suggests the findings are solid.

“Our guidance early on had suggested giving hydroxychloroquine to hospitalized patients, and we updated that guidance to remove that suggestion,” said Schluger afterward. That seems dramatic at first blush; if the jury’s still out on HCQ, why not continue to give it until results from a clinical trial is in? The answer, presumably, is that it’s foolish to risk side effects to patients when there’s no measurable benefit thus far. If a clinical trial proves otherwise they can always resume giving the drug later.

Thousands of people are being recruited in Michigan right now by the Henry Ford Health System for a clinical trial of hydroxychloroquine. But it sounds like doctors there have already started to sour on the drug too based on observations of how it’s working:

“There was a lot of hope for [hydroxychloroquine] initially, but it has not panned out,” said Dr. Dennis Cunningham, medical director of infection control at McLaren Health Care…

Last week, a research team lead by a Harvard Medical School doctor published a review of several studies, raising concerns about whether the drug might actually impair the body’s ability to fight the COVID-19 virus. The review called for limiting the drug to COVID-19 patients in a “carefully constructed randomized clinical trial.”…

Michigan Medicine also has stopped using hydroxychloroquine to treat COVID, unless the patient is enrolled in a clinical trial. That’s because of side effects ranging from vomiting to heart and liver problems, said Dr. Vineet Chopra, Michigan Medicine’s Chief of Hospital Medicine.

At least one doctor interviewed for that piece is still using it, believing that it might be keeping patients off ventilators and isn’t causing noticeable side effects. Cunningham, though, believes “that doctors are moving away from using it. It’s just not effective.”

Because not even medications are exempt from our increasingly surreal tribal culture wars, read Politico’s story from last week about champions of hydroxychloroquine questioning the efficacy of remdesivir because that drug never got the Trump/MAGA seal of approval like HCQ did.