Hi sco,
I would say things are pretty similar in the states, at least at my institution. You need to fill out a lot of paperwork including the procedures you're doing, how many mice you use typically, and then a justification. So we need to justify why we use mice instead of either a lesser organism (like zebrafish or worms) or in vitro methods.

As for PBK models, I don't have any experience in pharmaceutical research. My lab mostly looks at the innate immune system. Even our clinical research looks at bacterial carriage and not how drugs affect them. I did some cursory reading on it, and it seems like an interesting and useful tool!I do really enjoy modelling, so I will have to look into it further.

Thanks for the follow! I hope to be able to contribute some good material to the steemstem tag.