RESUMO
BACKGROUND: The relationship between SC-IFX concentrations and favorable therapeutic outcomes in patients with Crohn's disease (CD) and ulcerative colitis (UC) remain elusive. PATIENTS AND METHODS: This cross-sectional trial study included consecutive IBD adult patients with IBD treated with SC-IFX at maintenance dose of 120mg/2 weeks. Investigated therapeutic outcomes included sustained clinical remission; composite clinical and biomarker remission [clinical remission and CRP < 5mg/L]; biochemical remission [FC < 250 µg/g]; and deep remission [clinical, biological and biochemical remission]. RESULTS: Of 91 patients identified, 71 patients qualified for inclusion in the study (70% with CD; 27% with concomitant immunomodulators). At the time of drug concentration measurement (median 13.5 months after switch), 55 (77%) patients had sustained clinical remission; n=44 (62%) composite clinical and biomarker remission; n=40 (56%) biochemical remission; and n=31 (43%) patients deep remission. The mean SC-IFX concentrations were significantly higher in patients with sustained clinical remission [p=0.014]; composite clinical and biomarker remission [p=0.003]; biochemical remission [p<0.001] and deep remission [p<0.001] compared to patients without having these outcomes. In multivariate analysis, SC-IFX concentration was the only factor independently associated with sustained clinical remission [odds ratio (OR): 4.7, 95% CI: 3.1-12.2, p=0.005)]; clinical and biomarker remission (OR: 9.21, 95%CI: 6.09-18.7, p=0.006); biochemical remission (OR: 37, 95%CI: 14-39.3), p<0.001); and deep remission (OR: 29, 95%CI:15.7-37.4, p<0.001). The optimal SC-IFX concentration cut-off associated with deep remission based on ROC analysis was 20µg/mL (sensitivity: 0.91, specificity: 0.80, accuracy: 0.85). Combination with an IMM failed to improve SC-IFX pharmacokinetics. CONCLUSION: Higher SC-IFX concentrations are associated with higher rates of favorable therapeutic outcomes in IBD patients. Serum SC-IFX concentrations higher than 20µg/mL were significantly associated with deep remission.
RESUMO
Monitoring of anti-drug antibodies in patients on ustekinumab is not routinely recommended in patients with inflammatory bowel disease (IBD) due to low rates of immunogenicity. AIM OF STUDY: The purpose of this study was to investigate the relationship between anti-drug antibodies detected by a drug-tolerant assay and loss of response (LOR) to therapy in a cohort of patients with IBD being treated with ustekinumab. PATIENTS AND METHODS: This retrospective study consecutively enrolled all adult patients with moderate to severe active IBD who had at least 2 years of follow-up after ustekinumab was initiated. LOR was defined as CDAI > 220 or HBI > 4 for Crohn's disease (CD) and partial Mayo subscore > 3 for ulcerative colitis (UC) and with a modification in disease management. RESULTS: Ninety patients were included (78 CD and 12 UC; mean age 37 years). Median levels of anti-ustekinumab antibodies (ATU) were significantly higher in patients with LOR compared to those with ongoing clinical response (15.2 µg/mL-eq CI (7.9-21.5) and 4.7 µg/mL-eq CI (2.1-10.5), respectively; p = 0.04). The area under the ROC curve (AUROC) for ATU in predicting LOR was 0.76. The optimal cut-off point for identifying patients with LOR was 9.5 µg/mL-eq with a sensitivity of 80% and specificity of 85%. Uni- and multivariate analyses showed that serum ATU ≥ 9.5 µg/mL-eq (hazard ratio (HR) 2.54, 95%CI (1.80-5.93)), p = 0.022, prior vedolizumab (HR 2.78, 95%CI (1.09-3.34), p = 0.019) and prior azathioprine (HR 0.54, 95%CI (0.20-0.76), p = 0.014) exposures were the only factors independently associated with LOR to UST. CONCLUSION: In our real-life cohort, ATU was identified as an independent predictor of LOR to ustekinumab in patients with IBD.
