John: Hello, I'm John Hilton, senior editor at Cochrane. Cochrane is producing a series of living reviews relevant to the COVID-19 pandemic and, in August 2021, we published the first version of our review on remdesivir. We asked one of the authors, Felicitas Grundeis from the University of Leipzig Medical Center in Germany to tell us about the need for the review and its results.

Felicitas: Remdesivir was found to have anti-viral properties during the search for effective therapies for Ebola during the outbreak of that virus in West Africa a few years ago. This led to trials of it as a possible treatment for COVID-19 and the findings of early studies during the pandemic led to it being approved for emergency use in some countries. However, as more research was done, this produced inconsistent results and led to uncertainty about whether it should be recommended as a treatment.
To help resolve this, our living review investigates the effects of remdesivir compared to placebo or standard care alone in patients who are hospitalised with COVID-19. 
When we did the searches in April 2021, we found five completed randomised trials, involving a total of just under 7500 patients, and judged the overall quality of the available evidence to be moderate to very low. We were able to combine the results of four of the trials in our meta-analyses, using data from approximately 7100 patients. These four studies were all multicentred but most of the patients were in high- and middle-income countries. For the review, we wanted to focus in particular on the outcomes of mortality, course of clinical status, adverse events and quality of life; but there was limited reporting of these outcomes in the studies, which reported instead on outcomes such as time to improvement or recovery, or short-term clinical progression. None of them reported any data on quality of life.
Turning to our results, remdesivir probably has little or no effect on deaths within 28 days of its administration. It may decrease the need for invasive mechanical ventilation within this time period. However, the limited evidence means that the overall effect on clinical improvement and worsening is uncertain, although the drug does not seem to cause more adverse events then placebo or standard care alone.
In summary, this current version of our review shows that remdesivir probably does not have a relevant benefit on deaths and probably does not increase the risk of adverse events, but its effects on clinical progression or within specific population subgroups are uncertain. To resolve this, additional data on efficacy and safety, especially for different stages of the disease are needed, as well as agreement on, and use of, a set of core outcomes for measurement in COVID-19 research.

John: If you would like to read this first version of this living review of remdesivir, and watch for future updates as new research becomes available, the full text is available online. If you go to Cochrane Library dot com and search 'remdesivir and COVID-19', you'll find it.