P0656 Adalimumab mono vs. combination therapy in Crohn’s Disease: Real world experience
Authors: Babic F , Cacic P , Biscanin A , Kralj D , Ogresta Kordej D , Dorosulic Z , Hrabar D , Tomasic V 
Published: January 2025

Abstract

Background
The official ECCO guidelines/consensus paper strongly recommend adalimumab (ADA) monotherapy over combination therapy for both induction and maintaining remission in Crohn’s disease (CD). However, the supporting evidence is limited, ranging from low to moderate quality.

Methods
A retrospective, non-interventional, single-center chart review was conducted on bio-naïve and bio-experienced adult CD patients who were treated or had ongoing treatment with adalimumab from April 2012 to October 2024 at University Hospital Center Sestre milosrdnice, Zagreb, Croatia. Treatment persistence was evaluated as the primary outcome while therapeutic drug monitoring (TDM) and biochemical remission rates were analyzed for monotherapy (M) vs. combination therapy (C) groups. Biochemical remission was defined as Fcal&lt;150 µg/g and CRP&lt;5 mg/L. The minimum combination therapy duration was 6 months and secondary outcomes were measured at 6, 12 and 24 months after the introduction of therapy. Treatment persistence was assessed using Kaplan-Meier analysis. Repeated ANCOVA and Mann–Whitney tests were used for continuous variables and Chi-square test or Fisher exact test for categorical variables.

Results
Out of the 101 patients included in the study, 57.4% were male, with a median age of 36 (23-46) years. The median BMI was 23.1 (20.6–26.2) kg/m², and 31.7% of patients were smokers. Most patients were bio-naïve (81.2%) and anti-TNF-naïve (86.1%). Median disease duration was 65 (24–132.3) months. Combination therapy was used in 53.5% of patients, predominantly with azathioprine (81.1%), at a median dose of 1.6 (1.3-2) mg/kg for a median duration of 13 (7-23) months.
No statistically significant difference in treatment persistence was observed between the C and M group (χ2(1, N = 101) =.296, P = .59).
There was no significant difference found either in detection of ADA antibodies (p=.66 overall, p=.68 for TDM in the first 12 months) or in ADA serum levels (U=245, z=-0.258; p=.8) between the groups. Similarly, no statistically significant differences were observed in the rates of achieving biochemical remission at 12 months (χ2(1, N = 80) =1.014, P = .314). or in the dynamics of CRP (F(1,50)=.013, p=0.91) and FCal (F(1,38)=.001, p=0.97) values during the first year. In the subanalysis of anti-TNF-experienced patients, combination therapy was not associated with a higher rate of biochemical remission (p=0.57 for CRP and p=0.5 for Fcal), although the sample size within this group was limited.

Conclusion
In our cohort, adding an immunomodulator to adalimumab therapy did not improve treatment persistence, biochemical remission rates, serum drug levels, or prevent the development of anti-drug antibodies.

References
1.Gordon H, Minozzi S, Uri Kopylov, et al. ECCO Guidelines on Therapeutics in Crohn’s Disease: Medical Treatment. Journal of Crohn’s and colitis. Published online June 15, 2024. doi:https://doi.org/10.1093/ecco-jcc/jjae091‌
2.Matsumoto T, Motoya S, Watanabe K, et al. Adalimumab Monotherapy and a Combination with Azathioprine for Crohn’s Disease: A Prospective, Randomized Trial. Journal of Crohn’s and Colitis. 2016;10(11):1259-1266. doi:https://doi.org/10.1093/ecco-jcc/jjw152‌