Researchers just retracted a massive study on whether a common malaria pill can help treat coronavirus

• Some of the authors of a massive observational study of the antimalarial medication hydroxychloroquine published in The Lancet have retracted it.
• The study, published in May, had initially found that hydroxychloroquine and chloroquine did not appear to benefit coronavirus patients who took them and instead found that those who received one of the medications had a higher risk of death.
• The initial study led to the World Health Organization putting a temporary pause on the hydroxychloroquine arm of a trial it's running in light of the data. It later restarted the trial.
• In the weeks since, scientists had raised questions about the paper's statistical analysis and integrity of the data.

The authors of a massive study on the use of the antimalarial medication hydroxychloroquine in coronavirus patients published in the medical journal The Lancet retracted it on Thursday.

Initially published in May, the study had found that the treatments didn't appear to help patients hospitalized with the novel coronavirus and instead were associated with heart complications and an increased risk of death.

But in the weeks since the study was published, scientists have been raising questions about the paper's statistical analysis and integrity of the data, which are held by a US company called Surgisphere.

Initially, editors at The Lancet issued an "Expression of Concern," saying that serious scientific questions had been raised.

Some of the study's authors launched an independent third party peer review of the data used in the study, but said that Surgisphere wouldn't transfer over the full dataset.

"Based on this development, we can no longer vouch for the veracity of the primary data sources," the authors wrote on Thursday.

Another coronavirus study published in the New England Journal of Medicine that relied on Surgisphere data was retracted at the request of its authors on Thursday. That study, published May 1, centered on the use of certain heart drugs in patients with COVID-19.

The retracted Lancet analysis claimed to look at the hospital outcomes of 96,032 hospitalized patients, 14,888 of whom got some form of the antimalarial treatments chloroquine and hydroxychloroquine over the course of four months.

The patients came from 671 hospitals from six continents, and the study was led by researchers at the Brigham and Women's Hospital in Boston. Though it was not a randomized controlled trial, it was the largest study of its kind in patients with COVID-19, the disease caused by the novel coronavirus.

"The Lancet takes issues of scientific integrity extremely seriously, and there are many outstanding questions about Surgisphere and the data that were allegedly included in this study," The Lancet wrote in an accompanying note, adding that "institutional reviews of Surgisphere's research collaborations are urgently needed."

Read more: Drugmakers are racing to find ways to treat the novel coronavirus by repurposing existing medications. Here's what you need to know about remdesivir and 15 other leading treatments.

Shortly after the data was published, the World Health Organization put a temporary pause on the hydroxychloroquine arm of a trial it's running, then later restarted it. Additional randomized controlled trials — which preemptively assign patients either to the medication or a placebo control at random — are still underway.

Early in the pandemic, the drug caught the eyes of doctors, experts, and the Trump administration as a potential coronavirus treatment. Some early, promising results regarding the drug were published in late March.

President Donald Trump on May 18 said he had been taking hydroxychloroquine every day for a week and a half.

Other studies have cast doubt on how effective the drug might be in treating the novel coronavirus. A clinical trial taking place in Brazil was halted in April after a spike in deaths among patients who had received the drug.

The drug has not been approved by the US Food and Drug Administration for the treatment of COVID-19.

The University of Minnesota on Wednesday released results from its randomized controlled trial testing whether hydroxychloroquine can prevent coronavirus. The study is the first high-quality look at the medication's use in COVID-19. It focused on people who had been recently exposed to the virus and found that the drug did not help prevent infections.

Two observational studies, published in the New England Journal of Medicine and the Journal of the American Medical Association, found that among thousands of hospitalized coronavirus patients, those who received the antimalarial medication hydroxychloroquine didn't fare better or worse than patients who didn't receive the drug.

This article has been updated to show that the article was retracted at the request of some of its authors.