Huh, good question. I poked around a bit and saw some bloggy type articles, and so I looked on pubmed and got stymied because I guess "chemotherapy" is just a non-scientific collective term meaning "the use of a variety of drugs for cancer which are known to be cytotoxic, which appears to mean "toxic to cells." Medicine is so weird.

Anyway I played around with MeSH headings for a while and didn't find much, though I might have been searching the wrong terms. I did find one meta-analysis: Bakouny Z, Yared F, El Rassy E, Jabbour R, Hallit R, Khoury N, Honein K, Bou Jaoude J. Comparative Efficacy of Anti-TNF Therapies For The Prevention of Postoperative Recurrence of Crohn's Disease: A Systematic Review and Network Meta-Analysis of Prospective Trials. J Clin Gastroenterol. 2019 Jul;53(6):409-417. doi: 10.1097/MCG.0000000000001006. PMID: 29517709. And that work only identified nine prior studies! So there's a lot more work to be done, here. But in any case there has been some research identifying good drugs. I didn't look to see how well the drugs were tolerated, though.