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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
  • As Peter Lynch says, “buy good companies on bad news”. Make a decision about GILD based on whether or not you’d want to own it irrespective of Remdesivir. Remdesivir is merely the cherry on top. I’ve read there are 20 different drugs in trial from different companies so no telling who will get there first. The big question is does it work and there needs to be a sense of urgency for this and the other trials. My concern isn’t about making money . People are dying!!!!

  • Gilead is trying to save its expensive bacon with an old, prior not successful project on their shelves. Contradicting news is bad news. In a larger trial this drug also had no real improvement over “standard care”. But Mesoblast’s RYONCIL did (yesterday) : a whopping 83% success rate via 2 intravenous treatments of their remestemcel-L in 4 days. Ventilated moderate and severe Covid patients got off ventilators and are still alive. THAT is worth writing about : what the little, nimble, fast, innovative companies can do and ARE doing !

    • I would take anything from China with a little concern….Univ of Chicago or Stanford or any other medical/research/university in US, I would give a lot more credibility to. This does not mean our institutions are perfect….

  • People are dying while all this medical BS is going on. For example, the study is complete and we’ll see the results in mid May. How many people at the hospital in NY with the 88 percent mortality rate of ventilators patients would have been saved like the six critical patients from the cruise ship in Japan. As for side effects Remdesivir has been on the market a good while so there should be a lot of history. If it looks like a duck and walks like a duck it’s most likely a duck. If I were ever in the situation I ant the drug. Ps I am not an investor in GILD and have intention to do so.

  • I would be very interested to see interviews with the six people stuck on the cruise ship in Japan, 4 on ventilators 2 on heart lung machines who were treated with Remdesivir. What were their experiences both before and after treatment, particularly right after treatment? Particularly right after treatment. Also comments from the attending physician. This represents 6 out of 6 severe cases recovering. Then I read 88 percent of people on ventilators in a NY hospital dying. Wonder if any were on Remdesivir?

  • And the negative tests aren’t anecdotal, just as the news media calls everything positive that comes out of the Administrations meetings. Definitely let’s listen to the Chinese and WHO as reliable sources.

  • From another source about the same trial(s) including Dr Kathleen Mullane from University of Chicago Medical Center. Complete opposite of this article….Why don’t you guys interview Dr Mullane for her results????

    The world is watching and waiting for data to see whether Gilead Sciences’ investigational antiviral remdesivir can help fight COVID-19. And while some leaked early results suggest that it can, industry watchers will need to wait for data from Gilead’s own controlled phase 3 study to know for sure.

    Researchers at the University of Chicago Medical Center, which is treating patients with severe COVID-19, have seen remdesivir swiftly tamp down both fever and respiratory symptoms, according to a report from Stat. Gilead’s shares leapt more than 15% in after-hours trading following the report.

    “The best news is that most of our patients have already been discharged, which is great. We’ve only had two patients perish,” Kathleen Mullane, the University of Chicago infectious disease specialist overseeing the remdesivir studies for the hospital, said. She made the comments this week during a video discussion about the trial results with other University of Chicago faculty members. The discussion was recorded, and Stat obtained a copy of the video.

  • The WHO webpage image has incorrectly labeled the remdesivir study as “NEGATIVE”. It should be (should have been) INCONCLUSIVE given the confidence intervals of all studied outcomes cross zero, indicating statistical insignificance, so therefore neither ‘Positive’ nor ‘Negative’ can be claimed. (side note: a hazard ratio of 1.23 here would suggest remdesivir patients took ~23% longer to clinically recover compared to the control. However, given the CI of 0.87-1.75, it crosses zero so it could range anywhere from about 15% faster to 75% slower)

  • I suspect that someone in China is trying to short Gilead and/or the market to make a quick buck. Again another error from the WHO. What a joke they are. I bought GILD after the story broke, Gilead is a sound company and has a dividend of 3.5% with or without remdesivir.

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