Comparative Outcomes of Adalimumab and Infliximab Dose Escalation in Inflammatory Bowel Disease Patients Failing First-Line Biologic Treatment

<b>Background/Objectives:</b> Dose escalation has been commonly used to achieve and maintain response. We aimed to compare the outcomes of adalimumab or infliximab dose escalation in inflammatory bowel disease (IBD) patients. <b>Methods:</b> Treatment persistence (TP) and predictive factors for remission-free treatment discontinuation (r-fTD) were evaluated in patients treated with adalimumab or infliximab dose escalation between 2019 and 2024. <b>Results:</b> Dose escalation was identified in 142 patients treated with adalimumab (UC: 23.9%; CD: 76.1%) and in 126 patients treated with infliximab (UC: 23.8%; CD: 76.2%). The TP rate was significantly lower in the adalimumab group (35.2%) than the infliximab group (53.2%) (<i>p</i> = 0.003). The survival analysis showed that drug persistence was lower in the adalimumab group compared with the infliximab group (mean time: 74.3 vs. 99.5 months, <i>p</i> < 0.001). TP rates showed no significant differences between UC and CD for both adalimumab (mean time UC: 64.7 months vs. CD: 76.2 months, <i>p</i> = 0.403) and infliximab (mean time UC: 80.3 months and CD: 102.6 months, <i>p</i> = 0.151). The r-fTD rates were significantly higher in the adalimumab group (62.7%) than the infliximab group (39.7%) (<i>p</i> < 0.001). Primary lack of response and secondary loss of response (sLOR) rates were both higher in the adalimumab group (7.7% and 51.4%) than the infliximab group (1.6% and 28.6%). However, serious adverse events were lower in the adalimumab group (2.1%) than the infliximab group (7.9%) (<i>p</i> = 0.027). <b>Conclusions:</b> Infliximab dose escalation was more effective than adalimumab in both UC and CD patients. Regarding the side effect profile, adalimumab dose escalation was found to be safer compared with infliximab.