Aim: to compare the need for and time to adalimumab dose escalation and de-escalation between patients with Crohn's disease (CD) and ulcerative colitis (UC).
Methods: this observational cohort study included patients with luminal CD or patients with UC treated with adalimumab. Adalimumab dose optimization was decided based on the Harvey-Bradshaw index (CD) or the partial Mayo score (UC). The co-primary endpoints were the differences in the rate of dose escalation and the cumulative probability of escalation-free survival between cohorts. We also evaluated the rates of de-escalation and predictors of adalimumab dose escalation and de-escalation.
Results: twenty-four of 43 CD patients (56%) and 28 of 43 UC patients (65%) required adalimumab dose escalation. UC patients had a higher adjusted rate of dose escalation (hazard ratio [HR] 2.33, 95% confidence interval [CI] 1.19-4.56; p = 0.013) than CD patients. The median time to dose escalation was significantly shorter for UC than CD patients (3.2 months, interquartile range [IQR]: 2.0-10.3 vs 12.2 months, IQR: 6.1-35.7; p = 0.001). Survival curves showed that UC patients had an increased probability of dose escalation (p < 0.001). Prior anti-TNF therapy was associated with dose escalation (HR 2.13, 95% CI 1.05-4.34; p = 0.037). Adalimumab dose de-escalation was attempted in 32% of UC patients and 50% of CD patients. Survival curves showed that CD patients had an increased probability of dose de-escalation (p = 0.030).
Conclusion: UC patients more frequently required adalimumab dose escalation than CD patients. UC patients required optimization earlier than CD patients. More CD patients than UC patients can be dose de-escalated later on during treatment.