Remdesivir study in China shows no benefit for COVID-19

In a conflict with findings of two recent trials of the remdesivir drug, a small study in China has found that treatment with Gilead Sciences' investigational antiviral drug does not speed up recovery from COVID-19, compared with placebo in hospitalised patients who are critically ill.

The study involved 237 adults (aged 18 and older) from 10 hospitals in Wuhan, China.

Although this study, published in the journal The Lancet, is a randomised controlled trial (considered the gold standard for evaluating the effectiveness of interventions) of remdesivir, the authors caution that interpretation of their findings is limited.

This is because the study was stopped early after they were unable to recruit enough patients due to the steep decline in cases in China.

The original target was to include 453 patients in the study.

In the trial, all patients received standard care including lopinavir-ritonavir, interferons, and corticosteroids.

"Unfortunately, our trial found that while safe and adequately tolerated, remdesivir did not provide significant benefits over placebo," said Professor Bin Cao from China-Japan Friendship Hospital and Capital Medical University in China, who led the research.

"This is not the outcome we hoped for, but we are mindful that we were only able to enrol 237 of the target 453 patients because the COVID-19 outbreak was brought under control in Wuhan."

These results conflict with findings of two other trials of the drug.

Announcing the results of one of these trials, the US National Institutes of Health (NIH) on Wednesday said that patients hospitalised around the world with COVID-19 who received remdesivir (1,063 patients in total) had a 31 per cent faster recovery rate -- 11 days on average until discharge from hospital – compared to those receiving a placebo who took an average of 15 days.

In addition to this study, results of the company's open-label Phase 3 SIMPLE trial in patients with severe Covid-19 disease demonstrated that patients receiving a 10-day treatment course of remdesivir achieved similar improvement in clinical status compared with those taking a 5-day treatment course.

Results of these two trials have raised hope that remdesivir could emerge as a possible treatment for COVID-19, leading US President Donald Trump to express his wish that the Food and Drug Administration (FDA) approve the antiviral as soon as possible so that it can be administered against the virus.

However, the results of the study in China did not do much to bolster this optimism.

In this study, 237 adults hospitalised with severe laboratory-confirmed SARS-CoV-2 infection were enrolled between February 6 and March 12.

Participants were randomly assigned to either daily infusions of remdesivir (158 patients; 200mg on day 1 followed by 100mg on days 2-10) or a placebo infusions (79 patients) for 10 days. One patient in the placebo group withdrew before receiving treatment.

The results showed no statistically significant difference in time to clinical improvement was noted between the groups --average time to clinical improvement 21 days for remdesivir group vs 23 days placebo group.

The researchers of the study, however, concluded that more evidence from ongoing clinical trials is needed to better understand whether remdesivir can provide meaningful clinical benefit.

In the absence of any known treatment for COVID-19, remdesivir is one of a handful of experimental drugs undergoing clinical trials worldwide.

It has only been available to patients with COVID-19 on compassionate grounds (the use of unapproved drugs when no other treatment is available).

Remdesivir was originally developed to treat Ebola, and is designed to interfere with the way a virus reproduces, thereby stopping it from multiplying inside the body.

It has been shown to successfully block SARS-CoV-2 from replicating in vitro, and had activity against other coronavirus infections like severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and COVID-19 in animal studies.

Case studies have also reported benefit in some severely ill patients with COVID-19.

However, the maker of the drug warned that remdesivir has not yet been licensed or approved anywhere globally and has not yet been demonstrated to be safe or effective for the treatment of COVID-19.