Efficacy and Safety of Advanced Oral Small Molecules for Inflammatory Bowel Disease: Systematic Review and Meta-Analysis.

Background and aims: Oral small-molecule drugs [SMDs] are expanding the therapeutic landscape for inflammatory bowel disease [IBD]. This systematic review and meta-analysis summarizes the efficacy and safety of JAK inhibitor [JAKi] and sphingosine-1-phosphate [S1P] receptor modulator treatments for ulcerative colitis [UC] and Crohn's disease [CD].

Methods: MEDLINE, Embase, and CENTRAL were searched from inception to May 30, 2022. Randomized controlled trials [RCTs] of JAKi and S1P receptor modulators in adults with UC or CD were eligible. Clinical, endoscopic, histological, and safety data were pooled and analysed using a random-effects model.

Results: Thirty-five RCTs [26 UC, nine CD] were included. In UC, JAKi therapy was associated with induction of clinical (risk ratio [RR] 3.16, 95% confidence interval [CI] 2.03-4.92; I2 = 65%) and endoscopic [RR 3.99, 95% CI 2.36-6.75; I2 = 36%] remission compared to placebo. Upadacitinib was associated with histological response [RR 2.63, 95% CI 1.97-3.53]. S1P modulator therapy was associated with induction of clinical [RR 2.52, 95% CI 1.88-3.39; I2 = 1%] and endoscopic [RR 2.39, 95% CI 1.07-5.33; I2 = 0%] remission relative to placebo. Ozanimod was superior to placebo for inducing histological remission in UC [RR 2.20, 95% CI 1.43-3.37; I2 = 0%], while etrasimod was not [RR 2.36, 95% CI 0.71-7.88; I2 = 0%]. In CD, JAKi therapy was superior to placebo for induction of clinical remission [RR 1.53, 95% CI 1.19-1.98; I2 = 31%], and endoscopic remission [RR 4.78, 95% CI 1.63-14.06; I2 = 43%] compared to placebo. The risk of serious infections was similar for oral SMDs and placebo.

Conclusion: JAKi and S1P receptor modulator therapies are effective in IBD for inducing clinical and endoscopic remission and, in some circumstances, histological response.