Outcomes of adalimumab biosimilar ABP 501 in patients with inflammatory bowel disease: Comparison of adalimumab naïve and switching from originator

Background: In this study, we aimed to compare the effectiveness and safety of the ABP 501 molecule in inflammatory bowel disease patients who were ADA-naive and those who were switching from the originator molecule.

Materials and Methods: Data was prospectively collected between March 2020, and October 2022. The outcomes of the study were therapeutic failure free remission, and therapeutic failure.

Results: Seventy-four patients were analyzed for the ABP 501-ADA naïve group (67.9% males; 9.4% biologics experienced; 69.8% CD; 30.2% UC) and ABP 501-ADA switch group (47.6% males; 14.3% biologics experienced; 85.7% CD; 14.3% UC). Median total disease duration was 5.95 years (IQR 2.68-11.89), and follow-up time was 10.43 months (IQR 5.78-15.75). Median follow-up time was 9.23 months (IQR: 4.90-16.07) and 11.47 months (IQR: 7.47-15.39) after starting ABP 501-ADA naive and switch group, respectively (p= 0.297). Over this period, there was no significant difference between ABP 501-ADA naive and switch groups respectively, in the rates of therapeutic failure-free remission (86.8% vs. 90.5%) or therapeutic failure (13.2% vs. 9.5%), (p>0.05). Mean therapeutic failure-free survival was 21.12 months (95% CI: 19.12-23.11) in the ABP 501-ADA naïve group and 25.56 months (95% CI: 21.19-29.94) in the ABP 501-ADA switch group. There was no significant difference in terms of therapeutic failure-free survival between the two groups (p=0.207).

Conclusion: Results from this study showed no significant differences between the ABP 501-ADA naïve and the 501-ADA switch group in terms of therapeutic failure-free remission. The two groups were also found to be similar in terms of therapeutic failure-free survival.