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The antiviral medicine remdesivir from Gilead Sciences failed to speed the improvement of patients with Covid-19 or prevent them from dying, according to results from a long-awaited clinical trial conducted in China. Gilead, however, said the data suggest a “potential benefit.”

A summary of the study results was inadvertently posted to the website of the World Health Organization and seen by STAT on Thursday, but then removed.

“A draft manuscript was provided by the authors to WHO and inadvertently posted on the website and taken down as soon as the mistake was noticed. The manuscript is now undergoing peer review and we are waiting for a final version before WHO comments on it,” said WHO spokesperson Daniela Bagozzi.


Gilead spokesperson Amy Flood said the company believes “the post included inappropriate characterization of the study.” Because the study was stopped early because it had too few patients, she said, it cannot “enable statistically meaningful conclusions.” However, she said, “trends in the data suggest a potential benefit for remdesivir, particularly among patients treated early in disease.”

The data (for details, see screenshot below) will be closely scrutinized but are also likely imperfect. The study was terminated prematurely, which could have affected the results. The context that would be provided by a full manuscript is missing, and the data have not been reviewed as normally occurs before publication.


Many studies are being run to test remdesivir, and this one will not be the final word. Results are expected soon from a Gilead-run study in severe Covid-19 patients, although that study may be difficult to interpret because the drug is not compared to patients receiving only standard treatment. Encouraging data from patients in that study at the University of Chicago were described by researchers at a virtual town hall and obtained by STAT last week. However, unlike those data, these new results are from a randomized controlled trial, the medical gold standard.

Gilead is also running a study with a control group in more moderate Covid-19 patients, and the National Institute of Allergy and Infectious Diseases is running a study that compares remdesivir to placebo. There are even more studies of the drug ongoing.

According to the summary of the China study, remdesivir was “not associated with a difference in time to clinical improvement” compared to a standard of care control. After one month, it appeared 13.9% of the remdesivir patients had died compared to 12.8% of patients in the control arm. The difference was not statistically significant.

“In this study of hospitalized adult patients with severe COVID-19 that was terminated prematurely, remdesivir was not associated with clinical or virological benefits,” the summary states. The study was terminated prematurely because it was difficult to enroll patients in China, where the number of Covid-19 cases was decreasing.

An outside researcher said that the results mean that any benefit from remdesivir is likely to be small.

“If there is no benefit to remdesivir in a study this size, this suggests that the overall benefit of remdesivir in this population with advanced infection is likely to be small in the larger Gilead trial,” said Andrew Hill, senior visiting research fellow at Liverpool University.

He added that the results of the study should be pooled with larger studies being conducted by Gilead using a technique called meta-analysis to allow for “a balanced view of the efficacy of remdesivir from all randomized trials.”

STAT contacted the lead investigator of the study but did not receive an immediate response.

As originally designed, the China study was meant to enroll 453 patients. The patients were allowed to enter the study up to 12 days from the onset of Covid-19 symptoms. Once enrolled, the patients were randomized in a double-blind fashion and were treated with daily infusions of remdesivir or a placebo for 10 days.

The primary goal is to show that the drug is better than placebo at improving symptoms within 28 days. That improvement is measured with a six-point scoring system ranging from hospital discharge (a score of 1) to death (a score of 6). In order to count as someone who responded to the drug, a patient must improve by at least two points. Patients can remain hospitalized at the end of the 28-day period of the clinical trial but still improve enough clinically — no longer needing intubation or supplemental oxygen, for example — to count as a responder.

According to the abstract, 158 patients received remdesivir and 79 patients were in the control arm; one patient in the control arm withdrew before receiving treatment. The abstract said that for time to clinical improvement, the hazard ratio was 1.23, which would normally mean the patients on remdesivir improved more slowly than those in the control group.

However, in a previous note to investors preparing them for the data, Umer Raffat, a biotech analyst at Evercore ISI, had said to expect the opposite arrangement: that a hazard ratio of 1.2 would show patients were doing better. It is not certain how the hazard ratio is being described in the abstract.

Whether or not the drug benefit is trending in a positive or negative direction, the difference described in the abstract is not statistically significant, meaning that the study failed.

There are differences in the enrollment criteria of Covid-19 patients and the way remdesivir is being used that make extrapolating results from this China study to the ongoing studies difficult.

Flood, the Gilead spokesperson, said the company regrets that “the WHO prematurely posted information regarding the study, which has since been removed” and emphasized that the researchers running the study “did not provide permission for publication of results.” She said the data are expected to be published in a peer-reviewed journal soon.

WHO Remdesivir Screen
A screenshot from the WHO website. Screen capture
  • so the drug wasn’t even given until 12 days after someone got symptoms.

    OK, why did the CCP set this trial up for failure? I wonder if they’ll force a homegrown company to have the same type of enrollment criteria.

    (yeah right…)

    • Many trials are designed like this. Some trials look at patients in early stages of disease after signs crop up. Some look at patients with more advanced disease, including many American trials.

  • Is it reasonable to expect a significant effect on patients with advanced coronavirus? With most antivirals, you need to give the drug within the first couple of days of being infected in order for it to be effective. It seems not surprising that Remdesivir would be similar. Coronavirus seems to be fatal because of the body’s reaction to the virus, not just to the virus itself. So, at a late stage, maybe the damage has already been done.

    Very unfortunate if it doesn’t work out though, Remdesivir seemed like it had a sound mechanism and was the best hope of the treatments available.

    • Like others have said, the sequence data on COVID19 and virtually all the other critical early data came out of China and have been backed up so yes, this is a case when believing in Beijing makes sense. The work they’ve done has been sound and corroborated in other labs and clinics.

  • You simply don’t understand China. Even scientific studies in China are under control by CCP to serve a bigger political agenda – make its people proud of their own culture and technology and make the west look either stupid or bad. In the early stage of pandemic, CCP President Xi publicly requested that Chinese herb medicines be better promoted and more used in the treatment of patients. There are doctors, who complained the use of herb medicines, punished by CCP. No surprise, under such political agenda, a study of western, especially US, medicines MUST NOT be reported successful. I think more and more people have now realized how “accurate” a CCP data could be. Nevertheless, there are many other on-going studies elsewhere in the world which we can comfortably rely on.

  • Because China is the biggest market. But don’t worry, president Trump can sign executive order to ban those drug companies and their drugs and vaccines from US, just like what did to Huawei. We will see more and more such executive orders to ban Chinese companies in the next ten years when american companies lose in competition in every field.

  • I would not believe any data from China. Publishing data in this fashion is totally irresponsible. The patients were not started on treatment for 12 days after presentation. This makes absolutely no sense from a medical standpoint. No clinician would withhold antibiotics or antiviral treatment for 12 days after a diagnosis and expect a favorable outcome. I would suggest great caution in using data from China, what is there motivation!

    • So then would you not believe the data on the COVID19 viral sequence either? That first came out of China, and it turned out to be correct which is why we have tests for the virus. Would you not believe Chinese publications on the details and sources of COVID19 spread, how it causes disease in the body? Because those too have been corroborated in the USA and Europe. China’s data has been among the best in the world on this, whether you like it or not. So rather than simply pulling these accusations out of nowhere, do your homework first.

  • Conflicting reports and errors from such organizations render incomplete information and such premature posts rarely provide factual representations. Clinical studies and future releases become even more suspect. That’s sad. However, he less severely impacted patients within the other studies may certainly, hopefully yield promising results. No need to join the cynics! Stick to the protocols of the studies and the facts.

  • This is a highly irresponsible headline !! The reason they removed the data is because it was flawed , and that was one study in China . Multiple studies in the US including the one at the University of Chicago showed great hope . Hundreds of patients 99% survival rate among the sickest hospitalized patients, which would be even higher among moderately ill patients. Miraculous fever drop within hours of the first dosage , off ventilators within a day , home within 3 days . Yes this antiviral has great promise, unlike the drug Trump promoted that did nothing and caused more deaths .

    • Unless trials in Chicago etc are control studies with a lot of people, it means very little. Are they? You can’t take a limited amount of people with no control group and give them a drug and say oh they got better so the drug must be a success. They may have gotten better without it since most do. That is the issue with a lot of what is going on out there. And the company did not deny the results exactly. But we can hope there are big studies going on with a control group. The problem with Trump encouraging drugs, everyone rushes out to get their unethical drs to prescribe it and then you have trouble finding large legit groups of people for a controlled study to perform the study on. A huge problem.

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