Kiwi, pulling out of the US totally makes no economic sense and will not happen. They could get rid of all the sales reps and promotion and just be like the generics and supply demand, whatever that ends up being. Instantly the US is a big positive to earnings, making more than the EU per script or anywhere else for that matter. Yes, over time they would lose market share(already happening) but would be raking it in in the meantime.
Furthermore, about the worst thing you could do considering you are involved in an infringement suit is pull out of the very market you are trying to defend. You can't claim they are eating into your indication if you abandoned it.