I'm not a doctor. I haven't worked in a wet lab. All this is from second hand conversations and anecdotes.
Mice aren't human.
There's lots of ways to cure cancer in mice. it's practically a joke. Mice can tell you a bit about danger - if your treatment kills the mouse, think pretty hard about that treatment on a human. It might kill the human too, but maybe not. Might be ok for the mouse but not the human, like maybe thalidomide.
The impression I get is, if it's ok for mice it _might_ be ok for humans, so it helps avoid a large swath of super dangerous stuff. But doesn't tell you a whole lot about what happens in humans. I'm sure there are things that kill mice that are effective treatments for humans, but both of those edges are outlier-ish. If it kills the mouse it's probably not worth continuing without a good understanding of why it might work in humans.
Mice aren't human.
There's lots of ways to cure cancer in mice. it's practically a joke. Mice can tell you a bit about danger - if your treatment kills the mouse, think pretty hard about that treatment on a human. It might kill the human too, but maybe not. Might be ok for the mouse but not the human, like maybe thalidomide.
The impression I get is, if it's ok for mice it _might_ be ok for humans, so it helps avoid a large swath of super dangerous stuff. But doesn't tell you a whole lot about what happens in humans. I'm sure there are things that kill mice that are effective treatments for humans, but both of those edges are outlier-ish. If it kills the mouse it's probably not worth continuing without a good understanding of why it might work in humans.