Problem with biologics is that you can never really know how long you can take them. Some people who take them for years all of a sudden stop tolerating them and have to drop out of using them
For what it's worth, though, many people don't develop resistance, or at least not for a loooong time. My gastro told me one patient of his has been on Remicade for 15+ years and it's put them in happy remission the whole time.
Not everyone's a success story, but the success stories are very very good.
Yes, but I have also seen people who used biologics for 10 years without issue, and out of the blue they started to have severe side effects that made them move drop off (or move to another one). You just never know.