Gilead shares tumble on reports that the Chinese trial of its coronavirus drug was not successful

April 23, 2020, 7:53 PM UTC

Gilead Sciences shares plunged after reports that its experimental drug being tested in Covid-19 patients failed to show a positive result in a Chinese trial.

The drug company and a scientist involved in the trial disputed that characterization, however.

According to reports from the Financial Times and Stat, the drug, called remdesivir, didn’t make a significant difference in the amount of time it took patients to improve, or their likelihood of death. A summary of the trial results was posted and quickly removed by the World Health Organization, according to the publications.

Gilead shares were down 4.3% to $77.82 at 1:09 p.m. in New York.

The summary posted by Stat shows results from 237 patients in the trial. Use of the drug wasn’t associated with patients getting better, faster. And 13.9% of patients getting the drug died, versus 12.8% getting standard care, according to the summary.

Frederick Hayden, an infectious disease expert at the University of Virginia School of Medicine who helped the Chinese doctors conduct the study, disputed the characterization that the study had failed.

“That is not correct,” Hayden said in an interview, when asked whether the results showed remdesivir had flopped. “My interpretation of them is not consistent with that headline.”

Gilead, in a statement, said that the summary mischaracterizes the results of the study, which was stopped early after not enough patients could be found. A study with low enrollment can lead to results that are less conclusive.

Hayden said there was a mistake in the original manuscript and that it had since been revised. He said that the study was under review at a journal, which he would not identify, and that the authors were still waiting for page proofs. He declined further comment or elaborate until the study was published.

Gilead’s stock has been whipsawed by incremental reports on the drug, as investors grasp for any sign of data that the company’s compound could be an effective therapy for Covid-19 patients. Last week, the shares surged 9.7% on April 17 after a report that the drug appeared to have helped a group of Chicago patients who were part of a separate, wider trial.

Gilead, in its statement, said that “trends in the data suggest a potential benefit for remdesivir, particularly among patients treated early in disease.” The company said that the full data are being submitted for review and publication.

The study in question was one of two main trials in China of remdesivir, and looked at patients with severe cases of Covid-19. This group was considered one of the hardest to treat with antiviral drugs, as by the time the disease becomes advanced there may already be significant lung damage. In addition, the immune system may spin out of control in some patients with advanced disease, a process that antivirals like the Gilead drug won’t help with.

The study ran into enrollment difficulties as the epidemic in China slowed down and wasn’t able to get anywhere near the number of patients it had aimed for. This meant the study was likely to show an inconclusive result, unless the drug was massively beneficial or massively harmful.

The authors of the study provided a draft document to the WHO, which had asked for information to be shared early, and it was inadvertently posted on a research-sharing platform, according to Tarik Jasarevic, a WHO spokesman. The study is undergoing peer review and the WHO is awaiting a final version before making any comments. The document was removed from the site as soon as the mistake was noticed, the spokesman said.

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