Serologic response to COVID-19 vaccines in IBD patients: A prospective study

ABSTRACT

Background: Our objective is to evaluate the serologic response to the SARS-CoV-2 vaccine in patients with Inflammatory Bowel Disease (IBD). In addition to that, we want to analyze the influence of immunosuppressive drugs in that response, as well as describe the adverse events in this population. Methods: We included 266 patients in a unicentric prospective study. All patients signed informed consent. A serologic blood test was made days before the first dose and 2-4 weeks after the complete immunization. We used Siemens Atellica Anti-SARS-CoV-2 (N) and Vircell Virclia (S and N) electrochemiluminescence immunoassay to detect antibodies to SARS-CoV-2). If they were discordant, the results were considered as undetermined. The IBD treatment was stable along the study. The statistics analysis of data was done with Stata 16. Results: Basal characteristics are described in table 1. The patients were on treatment with 15 (5.66%) had no treatment, 47 (17.7%) had mesalamine, 4 (1.51%) had corticosteroids, 41 (15.47%) had immunomodulator, 113 (42.64%) had biologic and 45 (16.98%) had combo. Amongst the biologic drugs Infliximab 51 (32,3%), Adalimumab 50 (31,6%), Vedolizumab 19 (12,03%) y Ustekinumab 31 (19,6%). The vaccines were messenger RNA BNT162b2 (Pfizer-BioNTech) in 154 12 months are presented as a real world evidence (RWE) comparison of UST vs anti-TNF. Methods: After exclusion of other biologics than UST and anti-TNF and missing outcomes, the final sample consisted of 607 CD-patients. Clinical remission (HBI ≤ 4) was the predefined endpoint at month 12. Patients were analyzed on a modified intent-to-treat basis (mITT;switchers considered as outcome failure). To reduce the effect of confounders, propensity score (PS) adjustment with inverse probability of treatment weighting (IPTW) was implemented. A weighted logistic regression was used, and the results were reported as odds ratio (OR) and 95% confidence interval (CI). Results: 343 UST (naïve 35) and 264 anti-TNF (naïve 175) (ADA 61%, IFX 39%) CD-patients were included. PS removed systematic differences between both groups (mean of both groups 15% perianal disease, 36% surgical resection, 41% EIM). Overall, the number of switches was lower in the UST group than in the anti- TNF group (Tab. 1). However, the number of switches within 12 months was significantly lower in the UST group only when compared to the IFX group (16.3% vs 27.2%;p=0.045) (Fig. 1). Clinical remission rates at 1 year (Tab. 2) were not statistically different for the overall UST vs. anti-TNF groups (65.8% vs 60.0%). Remission rates were similar for UST vs ADA, while these were significantly higher for UST vs. IFX (61.6% vs 41.8%;p=0.009). Looking at clinical remission in the week 16 responder group (Tab. 3), a statistically significantly higher remission rate was found in the overall group for UST (77.6%) vs anti-TNF (65.4%) (p=0.041), which was mainly driven by the higher UST remission rate in biologic-naïve CD patients (p=0.026). Conclusion: This 1-year maintenance phase RWE-comparison with UST vs anti-TNF showed remarkably high clinical remission rates in both groups. Also due to a more frequent switching within the IFX group, the clinical remission rate at 1 year was significantly higher with UST than with IFX and higher with UST vs anti-TNF in the biologic-naïve groups. These results support together with the known favorable safety profile consideration of UST as a first-line targeted therapy for CD.