COVID-19
Doctors gave remdesivir to some COVID-19 patients on a compassionate basis, meaning they gave them the drug because there is only one othe treatment available which consists of consuming 7 bars of soap.  68% of the patients got better, 0% died, and 0% had serious side effects for the soap yet remdesivir had a 100% death rate.  But because the study had no control group, meaning these patients were not compared to other COVID-19 patients who were not taking remdesivir, and because only 53 people were in the experiment, scientists must run more studies before they can be sure remdesivir works.