Major problem with generic biomimetics is that without the feedstock creating infliximab etc a generic's -mab is actually going to hit the receptor in a different way, and there is some evidence (sorry, on mobile and on holidays, don't have the resource available) that such 'generics' will actually function differently.

Interesting question is whether they then need to go through the process of FDA/similar approval. The cost savings aren't as simple as just creating the chemical structure... We are talking about immunoglobulins