Clinical trials of an experimental antiviral drug said to "show promise" in treating the deadly coronavirus are still far from fulfilling patient recruitment targets more than two weeks in, raising questions about whether they can be completed within previously projected timelines.
Double-blind trials of Gilead Sciences' drug, remdesivir, are now taking place in 10 hospitals in Wuhan, vice-minister of science and technology Xu Nanping said at a press conference on Friday.
Currently, the trials involve more than 200 severe patients and over 30 mild or moderate cases, according to Xu. This is up from the 168 severe and 17 mild or moderate cases reported by Xu's colleague Zhang Xinmin at a separate press conference on Saturday, but still less than a third of the targeted total of 760 patients, according to documents for the study listed on ClinicalTrials.gov, an international clinical trial registry run by the United States National Library of Medicine.
The researchers had aimed to recruit 308 mild and moderate patients with the novel coronavirus and 452 severe cases, with both trials involving hospitalised patients with Covid-19, the respiratory disease caused by the virus, taking a nine-day dose of the drug to test its efficacy and safety.
Patients who have received any other experimental treatments within 30 days of the time they are screened are excluded from the remdesivir trials, according to the documents on ClinicalTrials.gov, possibly limiting the pool of qualified candidates, especially as authorities ramp up containment measures.
Gilead's chief medical officer Merdad Parsey told state-run press agency Xinhua on Monday that the company was expecting the results of clinical trials for remdesivir in April. World Health Organisation (WHO) director-general Tedros Adhanom Ghebreyesus had also said at a press conference on Thursday that preliminary results for the remdesivir trials as well as another experimental coronavirus treatment involving the combination of two HIV drugs, lopinavir and ritonavir, were expected in three weeks.
Gilead did not immediately respond to enquiries about whether the current shortfall in patient recruitment numbers was likely to delay the completion of the clinical trials.
China began tests for remdesivir early this month, after a US patient infected by the novel coronavirus showed signs of improvement from treatment with the drug, which was initially developed to fight the Ebola virus. Another patient in Bordeau, France also recovered after having been treated with the drug, according to French reports.
The tests are among more than 200 clinical trials for the novel coronavirus in China, according to the latest list published by the Chinese Clinical Trial Registry on Friday morning, as researchers race to combat the deadly virus which has killed more than 76,000 and caused over 2,200 deaths worldwide as of Friday.
Other treatments being tested, which range in intended function from prevention to rehabilitation, include HIV drugs, traditional Chinese herbal medicine and even Tai Chi, a form of Chinese martial art.
At the press conference on Friday, Xu said in vitro tests of remdesivir so far have shown a "very good inhibiting effect" on the coronavirus, but added: "I am waiting for the results (of the clinical trials) just like everybody else; I don't know more than anyone else does".
The vice-minister added that Chinese authorities have been in touch with Gilead. "If the drug works well, putting the interest of the people as the priority, we will work with Gilead to find an appropriate way to supply the medicine," he said.
Xu said two other potential coronavirus treatments in particular have had positive results: an antiviral called favipiravir that showed "fairly good performance" in 80 controlled trials in Shenzhen, and stem cell therapy, which helped four patients recover from severe Covid-19 and check out of hospital, he said, adding that there are plans to expand trials for both treatments.
Another treatment recommended by the National Health Commission in guidelines updated on Tuesday was the transfusion of blood from recovered patients, which would contain antivirals.
Xu said that by the end of Thursday more than 100 Covid-19 survivors had donated their blood, enough to be administered to more than 200 acute or severe patients.
In addition to treatments, Chinese researchers are developing vaccines for the virus through five different approaches, according to Zeng Yixin, vice-minister of the National Health Commission.
These include inactivated vaccines, a common technique which entails growing a virus that has had its infectivity destroyed by chemicals or radiation in a culture, as well as newer techniques such as genetic engineering. Some of the vaccines will begin clinical trials in April or May, Zeng said.
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