Remdesivir, an anti-viral drug first made to try and treat Ebola, has been used experimentally on Covid-19 patients since the outbreak’s early days.
It is approved for use by doctors in the UK and US based on early data suggesting it might be helpful, but scientific evidence has been mixed.
There are claims of miraculous recovery, improved survival odds and shorter illness, but other studies have found it makes no difference to patients in hospital with Covid-19.
Here is what research has found so far:
‘Highly effective’ in Chinese petri dish experiments (February)
Doctors writing in a study led by the Wuhan Institute of Virology, published in the prestigious scientific journal Nature in February, said: ‘Our findings reveal that remdesivir [is] highly effective in the control of 2019-nCoV infection in vitro.’
They added that, since the drug is proven to be safe in humans, it ‘should be assessed in human patients suffering from the novel coronavirus disease’.
Sudden turnaround in critically-ill US hospital patients (March)
George Thompson, an infectious disease specialist at the University of California Davis Medical Center, was part of a team that gave remdesivir to a sickly American woman with Covid-19 in February.
‘We thought they were going to pass away,’ Thompson told Science magazine. But 36 hours after the woman was admitted to hospital, doctors decided to treat her with remdesivir. Within a day, she saw a drop in the quantity of virus in her body and her condition began to improve.
Richard Childs, an assistant surgeon general and lung specialist at the National Institutes of Health, told The Wall Street Journal Friday that 14 American patients from the Diamond Princess cruise ship were treated with remdesivir in Japan.
‘Many of them were probably going to die in a short amount of time, and two weeks later nobody has died and more than half of them have recovered. It’s just absolutely amazing,’ he remarked.
‘Encouraging’ results from uncontrolled trial on 53 patients (April)
A study published in the New England Journal of Medicine in April revealed the effects the drug had on a group of 53 Covid-19 patients in the US, Europe, Canada and Japan.
Thirty-four of them were sick enough to require breathing machines. All were given the drug through an IV for 10 days or as long as they tolerated it.
After 18 days on average, 36 patients, or 68 per cent, needed less oxygen or breathing machine support. Eight others worsened. Four discontinued treatment because of health problems they developed.
Seven patients died, nearly all of them over age 70. That 13 per cent mortality rate appeared lower than seen in some other report, but comparisons were weak.
‘It looks encouraging,’ said Dr Elizabeth Hohmann, an infectious disease specialist at Massachusetts General Hospital.
Patients discharged after taking remdesivir in ‘hopeful’ Chicago trial (April)
University of Chicago Medicine recruited 125 people with COVID-19 as part of global clinical trials. Of those people, 113 had severe disease, STAT news reported in April.
All the patients were treated with daily infusions of remdesivir. The antiviral medication led to ‘rapid recoveries in fever and respiratory symptoms’, with ‘nearly all patients discharged in less than a week’, the study claimed.
Most of the patients were discharged after their symptoms eased over a week, and only two patients had died at the time of publication.
The paper’s author called the findings ‘hopeful,’ but cautioned it is difficult to interpret the results since they did not include comparison to a control group.
No benefit for patients with Covid-19, major Chinese study finds (April)
Chinese researchers published results from one of the first randomised controlled studies – the gold standard – of remdesivir in April.
Professor Bin Cao, from China-Japan Friendship Hospital and Capital Medical University in China, who led the research, said: ‘Unfortunately our trial found that, while safe and adequately tolerated, remdesivir did not provide significant benefits over placebo.’
Those on the placebo drug (78 people) had similar outcomes to those given remdesivir (158). It took a shorter time for the remdesivir-treated patients to get better, 21 days compared with 23, but this was not statistically significant.
There was a one per cent difference in mortality rate between the two groups, meaning it didn’t shower a clear benefit in survival rates.
It was also noted that a larger number stopped their treatment because of adverse events while on remdesivir, such as constipation and anaemia.
Independent scientists said the trial was too small to write off the drug and that it wasn’t the ‘end of the story’ for remdesivir.
Death rate cut from 12% to 7% among 1,000 patients (May)
A study published in the New England Journal of Medicine saw remdesivir cut the mortality rate of 1,063 hospital patients around the world.
Patients given remdesivir had a recovery time that was almost a third (31 per cent) faster than those given a placebo – 11 days compared to 14.
Results also suggested a survival benefit, with a lower mortality rate of 7.1 per cent for the group receiving the drug, compared with 11.9 per cent for the placebo group. But this is not deemed a significant difference.
Recovery rates improved by 65% (May)
Trial results published by remdesivir’s own manufacturer, Gilead, said it seemed to show improved recovery times for Covid-19 patients.
The ‘SIMPLE’ trial involved 600 people and evaluated five-day and 10-day courses of remdesivir plus standard care, versus standard care alone.
Each group in the study included around 200 patients who were hospitalised with moderate Covid-19, meaning they were sick but not in intensive care.
Patients in the five-day remdesivir treatment group were 65 per cent more likely to have clinical improvement at day 11 compared with those in the standard care group. The odds of improvement in clinical status with the 10-day treatment course of remdesivir versus standard care were also 31 per cent higher.
The statistic is favourable but did not reach statistical significance, Gilead said.
It was not clear why those given a longer treatment course did not get better as quickly as those in the five-day group.