Answer: Jak1 Only
Upadacitinib, a new FDA-approved therapy for UC, is a selective JAK1 inhibitor, thereby inhibiting IL-6 and IFN-gamma signaling. Baricitinib is a JAK1/2 inhibitor, with lesser effects on JAK3 and TYK2. It is used for rheumatoid arthritis. Tofacitinib is approved for UC, and is a JAK 1/3 inhibitor with less effects on JAK2 and TYK2.
- Sandborn WJ, Feagan BG, Loftus EV Jr, Peyrin-Biroulet L, Van Assche G, D’Haens G, Schreiber S, Colombel JF, Lewis JD, Ghosh S, Armuzzi A, Scherl E, Herfarth H, Vitale L, Mohamed MF, Othman AA, Zhou Q, Huang B, Thakkar RB, Pangan AL, Lacerda AP, Panes J. Efficacy and Safety of Upadacitinib in a Randomized Trial of Patients With Crohn’s Disease. Gastroenterology. 2020 Jun;158(8):2123-2138.e8. doi: 10.1053/j.gastro.2020.01.047. Epub 2020 Feb 8. PMID: 32044319.
