The Lancet, one of the world’s top medical journals, on Thursday retracted an influential study that raised alarms about the safety of the experimental Covid-19 treatments chloroquine and hydroxychloroquine amid scrutiny of the data underlying the paper.
Just over an hour later, the New England Journal of Medicine retracted a separate study, focused on blood pressure medications in Covid-19, that relied on data from the same company.
The retractions came at the request of the authors of the studies, published last month, who were not directly involved with the data collection and sources, the journals said.
“We can no longer vouch for the veracity of the primary data sources,” Mandeep Mehra of Brigham and Women’s Hospital, Frank Ruschitzka of University Hospital Zurich, and Amit Patel of University of Utah said in a statement issued by the Lancet. “Due to this unfortunate development, the authors request that the paper be retracted.”
The retraction of the Lancet paper is sure to add fuel to contentious arguments about the potential of chloroquine and hydroxychloroquine, two old malaria drugs, in Covid-19, the disease caused by the novel coronavirus. President Trump has touted them as valuable treatments, despite a lack of rigorous data showing they have a benefit.
Meanwhile, on Wednesday, researchers reported the results of the first gold-standard clinical trial of hydroxycholoroquine in Covid-19, concluding that it did not prevent infections any better than placebo. Other clinical trials, including some looking at the drugs as treatments, are ongoing.
The Lancet study gained so much attention because it went further than other observational studies that had similarly found the drugs were not associated with improved outcomes for patients. The study, which was purportedly based on patient data from 671 hospitals on six continents, reported the drugs also corresponded to higher mortality.
The findings led to the pause of some global clinical trials studying hydroxychloroquine so researchers could check for any safety concerns. Outside experts, however, quickly raised concerns after noticing inconsistencies in the data. They asked the company that compiled and analyzed the data, Surgisphere, to explain how it sourced its data.
As scrutiny grew, the authors on the paper not affiliated with Surgisphere called for an independent audit. In their Lancet statement Thursday, they said that Surgisphere was not cooperating with the independent reviewers and would not provide the data.
“As such, our reviewers were not able to conduct an independent and private peer review and therefore notified us of their withdrawal from the peer-review process,” the researchers wrote.
Outside experts raised similar concerns about the New England Journal study, which found that the blood pressure medications were safe to take for people with Covid-19. It was also based on data from Surgisphere.
In the New England Journal retraction statement, the study authors wrote, “Because all the authors were not granted access to the raw data and the raw data could not be made available to a third-party auditor, we are unable to validate the primary data sources underlying our article.” They apologized “for the difficulties that this has caused.”
Concerns about the health risks of chloroquine and hydroxychloroquine were based on evidence beyond the Lancet paper. Earlier, the Food and Drug Administration warned the drugs should not be used in Covid-19 outside a clinical trial or beyond hospitalized patients because of the risks to heart health.
The drugs are safe for people to take for malaria, rheumatoid arthritis, and lupus, for whom they are shown to have benefits, experts stress.