Objectives There are limited data regarding adalimumab (ADM) clearance in inflammatory bowel disease (IBD). The aim of this study was to identify factors associated with ADM clearance and to assess its association with mucosal healing. Methods This single-center, retrospective study included consecutive patients with IBD who received maintenance ADM therapy and underwent therapeutic drug monitoring (TDM) between January 2018 and May 2023. Drug clearance was determined using a nonlinear mixed-effect model with Bayesian priors. Mucosal healing was defined as an endoscopic Mayo score 1 or less; for ulcerative colitis, no ulcerations for patients with Crohn’s disease, or a Rutgeerts score of i1 or less for patients with an ileocolonic resection for Crohn’s disease and was evaluated within 3 months from TDM. Results The study population consisted of 263 patients with IBD (74% Crohn’s disease) who underwent a total of 515 TDM tests (388 proactive). Multivariable linear regression analysis identified that proactive TDM was associated with lower ADM clearance beta coefficients (β): −0.173, 95% confidence interval (CI): −0.180 to −0.088, P < 0.001, while BMI (β: 0.125, 95% CI: 0.005–0.013, P < 0.001), prior biologic exposure (β: 0.087, 95% CI: 0.022–0.112, P = 0.004), and antibodies to ADM (β: 0.676, 95% CI: 0.628–0.750, P < 0.001) were associated with higher ADM clearance. Receiver operating characteristic analysis identified an ADM clearance threshold of 0.301 L/day (area under the receiver operating characteristic curve: 0.731; 95% CI: 0.654–0.808; P < 0.001; sensitivity: 61%; specificity: 78%) distinguishing patients with or without mucosal healing. Conclusion This study demonstrated that lower ADM clearance is associated with proactive TDM and mucosal healing in patients with IBD.
Deyhim et al. (Mon,) studied this question.