It does seem to work (for some, especially former smokers) at least as well as conventional meds, and there is some evidence that when added to conventional meds it confers added benefit.
I am not a former smoker, but I would try this before biologics.
To be fair, nicotine is also drug, and while side-effects are mostly mild, so are the side effects of mesalamine.
the research has been hampered by studies with small samples, often 15-20 people. for a good review:
onlinelibrary.wiley.com/doi/10.1111/apt.12086/fullYou can skip down to "Discussion" if you want to avoid a lot of the technical jargon.