Yesterday many news reports announced positive results for remdesivir in treating Covid-19 patients. I found them so vague that I had trouble understanding their full impact. I finally found the link for that remdesivir clinical trial, and another link for an NIH press release describing it's results so far.
The clinical trial itself:
clinicaltrials.gov
This is a very big trial, more than 1,000 patients, taking place in as many as 100 different locations around the world. It's still going on. It was designed to allow interim analysis while the trial is still going on. This can give results faster than if we had to wait for final results:
"There will be interim monitoring to introduce new arms and allow early stopping for futility, efficacy, or safety. If one therapy proves to be efficacious, then this treatment may become the control arm for comparison(s) with new experimental treatment(s)."
The NIH press release from April 29, 2020.
Preliminary results indicate that patients who received remdesivir had a 31% faster time to recovery than those who received placebo.
www.nih.gov
Two paragraphs from the press release said:
An independent data and safety monitoring board (DSMB) overseeing the trial met on April 27 to review data and shared their interim analysis with the study team. Based upon their review of the data, they noted that remdesivir was better than placebo from the perspective of the primary endpoint, time to recovery, a metric often used in influenza trials. Recovery in this study was defined as being well enough for hospital discharge or returning to normal activity level.
Preliminary results indicate that patients who received remdesivir had a 31% faster time to recovery than those who received placebo (p<0.001). Specifically, the median time to recovery was 11 days for patients treated with remdesivir compared with 15 days for those who received placebo. Results also suggested a survival benefit, with a mortality rate of 8.0% for the group receiving remdesivir versus 11.6% for the placebo group (p=0.059).
interim analysis – This was the analysis of about 400 patients, half of whom received remdesivir. The faster time-to-recovery for remdesivir patients met the study's primary goal at the interim analysis time point. The p value,
p<0.001, means that this data fit the statistical model's prediction extremely well. In non-statistical language, this means the results are highly reliable. Data from a secondary goal, patient survival, had a p value of 0.059. In most statistical analyses of this kind of data, a p value of <0.05 is desired. So,
p=0.059 is close but no cigar. Hence the words "suggested a survival benefit" are used, instead of saying the data demonstrated or indicated a survival benefit.
Preliminary results – This trial is still going on. It's final results will be evaluated closely at a later time. It is possible that the final results may differ from those reported after interim analysis.
Overall, these results for remdesivir are very encouraging.
Compare the remdesivir reports with those we previously saw with hydroxychloroquine. Instead of a well designed clinical trial of hundreds, we were told "What have you got to loose?".