This was a phase 2/3 trial. So there was some side effect data collected, but enough people went through the trial to see any large/common side effects. I gene

This was a phase 2/3 trial. So there was some side effect data collected, but enough people went through the trial to see any large/common side effects. I generally think of the phases like this (this is just how I think of it): Phase 1 - is it safe? If you don’t see severe toxicity then you can go to phase 2. Phase 2 - does it work? You look for good outcomes (cures, better survival, etc). If there is significantly better outcomes relative to placebo, then go to phase 3. Phase 3 - does it work for a large population? What is the appropriate dose? Dialing in the numbers before public release. Phase 4 - after you’ve made the drug public, monitor the larger population for side effects or adverse events. You can’t hope to cover all patients in a phase 2/3 trial, so you keep monitoring the first waves of patients that get the drug.