Results from an ongoing phase 3 study published in the New England Journal of Medicine:

"Adverse events occurred at similar rates in both groups: 70% in the 5-day group and 74% in the 10-day group. The most common side effects included nausea (9%); worsening respiratory failure (8%); elevated alanine aminotransferase level, indicating liver damage (7%); and constipation (7%). Overall, 21% of patients in the 5-day group and 35% in the 10-day group had serious adverse events.

In the 5-day group, 4% of patients stopped treatment because of adverse events, versus 10% in the 10-day group. Adjusting for baseline clinical status revealed that only serious adverse events were different between the two groups, the most common of which in the 10-day group were acute respiratory failure (9% versus 5%) and respiratory failure (5% versus 2%).

After 14 days, 16 patients (8%) in the 5-day group and 21 patients (11%) in the 10-day group had died."

70% 'adverse events' sounds not too good.