It's not that strange to go straight to biologics, Almonds, especially for disease outside of the colon. Other than Pentasa, there are no mesalamines to treat the small bowel, where many people with Crohn's have active disease. Even though Pentasa is active throughout the entire digestive tract, I doubt it would be effective in your esophagus.
Have your DRs considered other sources of these upper GI ulcers? I'm thinking specifically of shingles. My MIL had shingles in her throat - I don't know if that's something you talked about
with your DRs.
Edited to add that I did a little googling on this and I really do think you need to talk to your GI about
other causes of this esophagus stuff. see this link:
www.atsu.edu/faculty/chamberlain/Website/lectures/lecture/GI3.htm