Doing drug development without animal testing is like trying to modify a huge, messy, legacy code base without integration tests. Our computer models are like

Doing drug development without animal testing is like trying to modify a huge, messy, legacy code base without integration tests. Our computer models are like unit tests. They are relatively self-contained and quick to run. However, they cannot test all the interactions and stuff we do t know about, so we have animal testing as a kind of integration test to make sure stuff works like expected. And a phase 3 clinical trial is like pre-prod. When you think everything works, you expose test it in the real world with very careful monitoring and plan to keep it from going out into prod if problems are found.