Bella Ungar

The temporal evolution of antidrug antibodies in patients with inflammatory bowel disease treated with infliximab

Objective To characterise the temporal evolution of antibodies to infliximab (ATI). Design Prospective observational study of infliximab-treated patients with inflammatory bowel disease between 2009 and 2012. Interventions Trough levels of infliximab and ATI were measured before each infusion by anti-λ ELISA. Patients were monitored for disease activity by clinical activity indexes and for dose-intensification or infliximab cessation. The occurrence of transient ATI disappearing spontaneously without intervention was recorded separately. Results 125 patients were included (98 Crohns disease, 27 ulcerative colitis, median follow-up 11.5±22 months) and 1119 sera were analysed for infliximab and ATI levels. Kaplan-Meier analysis showed that 42% of patients remained ATI-free by 4 years of treatment. Most (90%) of the patients who developed ATI did so within the first 12 months of therapy, whereas transient ATI were detected throughout the duration of infliximab therapy (p<0.001). ATI incidence was similar between patients who received infliximab previously (episodic/interrupted therapy patients, n=14) and scheduled-therapy patients (n=111). In the scheduled group, combination immunomodulator+infliximab resulted in longer ATI-free survival compared with monotherapy (p=0.003, logrank test). Survival free of clinical loss of response was enjoyed by 51% of patients, and serial measurements showed that ATI development often preceded the onset of clinical flare. Conclusions When followed prospectively, most patients who develop ATI do so within the first 12 months of therapy. This incidence is reduced by concomitant immunomodulator even in scheduled-therapy patients. In contrast, transient ATI, which are of little clinical significance, can appear haphazardly at any time during treatment. The onset of clinical loss of response may lag behind the appearance of anti-infliximab antibodies.

Cross-immunogenicity: antibodies to infliximab in Remicade-treated patients with IBD similarly recognise the biosimilar Remsima

Objective The cross-immunogenicity of the recently approved infliximab-biosimilar Remsima (CT-P13) with the originator drug Remicade is still unknown. Design Sera of patients with IBD with or without measurable anti-Remicade antibodies to infliximab (ATI) were tested for their cross-reactivity to two batches of Remsima. Experiments were repeated after deglycosylation of Remicade/Remsima, IgG purification, excipients’ dialysis and monomer purification by size exclusion chromatography. Anti-Remicade antibodies were tested for their functional inhibition of TNF-α binding by Remsima/Remicade by competition assay. Cross-reactivity of anti-adalimumab antibodies with Remicade/Remsima was also investigated. Results 125 patients’ and controls’ sera were tested (median age 31 years, IQR 24.5–39.5). All 56 anti-Remicade ATI-negative controls (14 healthy individuals, 42 patients with IBD) were also negative for anti-Remsima ATI. All 69 positive anti-Remicade IBD sera were cross-reactive with Remsima. ATI titres against Remicade or Remsima were strongly correlated (r values between 0.92 and 0.99, p<0.001 for all experiments, Spearmans correlation test). The background ELISA signal for Remsima was slightly higher compared with Remicade in negative controls (1.25±0.6 µg/mL vs 0.76±0.5 µg/mL, respectively, p<0.001), and persisted after deglycosylation, dialysis or protein size filtration, but abolished by IgG purification and significantly diminished by monomer purification. Anti-Remicade ATIs of patients with IBD (n=10) exerted similar functional inhibition on Remsima or Remicade TNF-α binding capacity (p=NS for all inhibition curve points). Antibodies-to-adalimumab in adalimumab-treated patients with IBD (n=7) did not cross-react with either Remicade or Remsima. Conclusions Anti-Remicade antibodies in patients with IBD recognise and functionally inhibit Remsima to a similar degree, suggesting similar immunogenicity and shared immunodominant epitopes on these two infliximab agents. In contrast, anti-adalimumab antibodies do not cross-react with Remsima or Remicade.

Undetectable anti-TNF drug levels in patients with long-term remission predict successful drug withdrawal.

Low drug levels are associated with emerging loss of response to anti‐TNF. However, this may not be the case in patients with long‐term remission.

Induction infliximab levels among patients with acute severe ulcerative colitis compared with patients with moderately severe ulcerative colitis.

Infliximab is effective as salvage therapy for patients with steroid refractory acute severe ulcerative colitis (UC). Although current data suggest that the pharmacokinetics of infliximab are influenced by inflammatory burden in patients with acute severe UC, data comparing infliximab trough levels in patients with acute severe UC vs. moderately severe UC are scarce.

Expression of IL-2, IL-17 and TNF-alpha in patients with Crohn's disease treated with anti-TNF antibodies

BACKGROUND The T cell cytokine IL-17 and the Th-17 pathway appear to have a role in the pathogenesis of inflammatory bowel diseases. IL-2 is a potent stimulator of lymphocyte proliferation and IL2/IL21 receptor polymorphisms have recently been associated with susceptibility to IBD. AIMS To evaluate the expression of IL-17, IL-2 and TNFα in Crohns disease (CD) patients with and without anti-TNFs. METHODS Cytokine expression was evaluated by ELISA and intracellular staining of CD4(+) T-cells from the peripheral blood and lamina propria of CD patients and of non-IBD controls. The results were stratified by disease activity and anti-TNF treatment. RESULTS IL2 expression was significantly elevated in CD patients not treated with anti-TNFs in comparison to healthy controls (19.6% vs. 33.3%, P=0.03) and CD patients treated with anti-TNFs (20.4% vs. 33.3%, P=0.02), and similar in infliximab-treated patients and controls. IL17 expression was similar in CD patients and controls, and was not affected by anti-TNF therapy. TNFα expression in patients with active CD was increased compared to controls (35.5% vs 25.7%, P<0.005), and was significantly decreased in anti-TNF treated patients in comparison to CD patients without anti-TNFs (39.6% vs 26.2%, P=0.01). CONCLUSIONS Expression of IL2 was significantly decreased in anti-TNF-treated CD patients in comparison to non-treated CD patients and controls. This novel finding may indicate a further mechanism of anti-TNF therapy in CD. Expression of IL17 was not influenced by presence of CD or anti-TNF therapy, which may partly explain the failure of recent clinical trials investigating anti-IL17 therapy in CD.

Advances in the development of new biologics in inflammatory bowel disease

Biologics have revolutionized the therapeutic approach in inflammatory bowel disease (IBD). Anti-tumor necrosis factor (anti-TNF) agents infliximab and adalimumab currently constitute the major biological therapy in IBD. Additional anti-TNFs such as golimumab and other new biologics are currently being developed for both anti-TNF-naïve and -resistant patients. These include anti-integrins (vedolizumab and etrolizumab), a JAK inhibitor (tofacitinib) and an anti-anti-interleukin (IL)-23 and IL-12 antibody (ustekinumab), among additional drugs in development. The following review discusses the indications, efficacy and safety issues for these novel medications.

Severe and morbid obesity in Crohn's disease patients: prevalence and disease associations.

Background: Crohns disease (CD) is frequently associated with weight loss and malnutrition. However, as the prevalence of obesity increases worldwide, it may become a clinical problem even in CD. Aim: To assess the prevalence of severe/morbid obesity in CD patients and to compare their disease characteristics to nonobese CD patients. Methods: A retrospective analysis of a computerized CD patient database was performed to identify severely/morbidly obese patients (BMI >35). Prevalence was compared to data of the general population. Severely/morbidly obese CD patients were then compared to randomly selected nonobese CD patients (BMI <30) in a 1:3 ratio. Results: Thirteen severely/morbidly obese patients out of 560 CD patients were found (2.3%), which is significantly lower than the prevalence in the general population (5.6%, p = 0.001). When compared to 39 nonobese CD patients, colonic disease was significantly more common among severely/morbidly obese CD patients (odds ratio: 6, 95% CI: 1.35-26.3, p = 0.02), while there was no difference in other disease parameters. Interestingly, 4 morbidly obese CD patients had undergone laparoscopic sleeve gastrectomy for treatment of morbid obesity with a favorable surgical course. Conclusion: CD in severely/morbidly obese patients is more often colonic, but otherwise no different than CD in nonobese patients. Sleeve gastrectomy is a viable therapeutic option for morbidly obese CD patients.

Vedolizumab in IBD–Lessons From Real-world Experience; A Systematic Review and Pooled Analysis

Background Vedolizumab [VDZ] is an anti-integrin monoclonal antibody effective in ulcerative colitis [UC] and Crohns disease [CD]. Several real-world experience [RWE] studies with VDZ have been published to date. The aim of this systematic review was to summarise the available real-life experience with VDZ. Methods We performed a systematic review of the available RWE studies of VDZ in CD and UC. We performed a pooled analysis of the available efficacy and safety data for induction and maintenance treatment in adult cohorts. A narrative review of VDZ use in special clinical settings was also performed. Results Nine studies including 1565 [571 UC, 994 CD] adult patients were identified. In CD, clinical response and remission were achieved in 54% (95% confidence interval [CI] 41-66%) and 22% [95% CI 13-35%] by Week 6 and in 49% [95% CI 37-51%] and 32% [95% CI 23-42%] by Week 14; at Week 52, 45% [95% CI 28-64%] and 32% [95% CI 12-62] of the patients responded, and were in clinical remission, respectively. In UC, clinical response and remission were achieved in 43% [95% CI 37-49] and 25% [95% CI 12-45] by Week 6, respectively, and in 51% [95% CI 43-61%]and 30% [95% CI 24-36%] by Week 14/22, respectively; at week 52, clinical response and remission were achieved in 48% and 39% of the patients, respectively. Adverse effects were mostly minor and occurred in 30.6% of the patients; infections were reported in 3.4% of the patients. Conclusions VDZ is efficacious in CD and UC and has a favourable safety profile in RWE studies.

Significance of low level infliximab in the absence of anti-infliximab antibodies.

AIM To evaluate the prevalence of double negative (DN) sera and the mechanisms responsible for DN status. METHODS Sera of inflammatory bowel disease patients treated with infliximab (IFX) were tested for drug/antibodies to infliximab (ATI) trough levels and the proportion of DN results was compared between a commercially available double antigen ELISA (with labeled IFX as the detection antibody) and an anti-lambda ELISA (with anti-human lambda chain detection antibody). Repeat testing with lower than customary serum dilution (1:10) was performed. Patients with DN status were matched with IFX+/ATI- controls and were followed-up for subsequent development of non-transient ATI to investigate if DN status precedes ATI. RESULTS Of 67 sera obtained at time of loss of response, only 6/67 (9%) were DN by anti-lambda ELISA compared to 27/67 (40%) with double antigen ELISA (P < 0.001, Fishers Exact test). Of the latter 27 sera, 22% were also DN by anti-lambda ELISA, whereas 44% were actually IFX positive (IFX+ATI-), 30% were ATI positive (IFX-ATI+) and 4% were double positive (IFX+ATI+). Re-testing using a 1:10 dilution converted most DN results into IFX+ and /or ATI+ status. Patients with DN status had shorter survival free of non-transient ATI compared with matched controls (log rank test, P < 0.001). In 9/30 (30%) of these patients, non transient ATI occurred before and after the event at which the DN serum was obtained, supporting the view that a DN result may represent a particular time-point along the two curves of ATI titer rise and infliximab drug level decline. CONCLUSION DN status may result from false negative detection of IFX or ATI by double antigen ELISA, suggesting a transitional state of low-level immunogenicity, rather than non-immunological clearance.

Ashkenazi Jewish Origin Protects Against Formation of Antibodies to Infliximab and Therapy Failure

AbstractInfliximab is an anti-tumor necrosis factor (TNF) used for treatment of inflammatory bowel disease (IBD) as well as rheumatoid arthritis, psoriasis, and other inflammatory conditions. Antibodies to infliximab (ATI) develop in approximately 45% of infliximab-treated IBD patients and are correlated with loss of clinical response. Scarce data exist as to factors which predict infliximab immunogenicity.To investigate factors that may predict formation of antibodies to infliximab (ATI) and infliximab therapy failure an observational study of consecutive IBD patients treated with infliximab between 2009 and 2013 was performed. Trough levels of ATI were measured. Patients were monitored for disease activity using clinical activity indexes and were classified according to ATI formation and clinical response. All clinical and demographic parameters were analyzed for association with the designated outcomes.One hundred fifty-nine patients were included and 1505 sera were tested. On multivariate analysis, Jewish Ashkenazi ethnicity was protective against both development of ATI (odds ratio [OR] 0.35, 95% confidence interval [CI] 0.17–0.7, P = 0.005) and treatment failure (OR 0.29, 95% CI 0.13–0.66, P = 0.003). Concomitant immunomodulator therapy was also negatively associated with immunogenicity and infliximab therapy failure (OR 0.31, 95% CI 0.15–0.65, P = 0.002; OR 0.42 95% CI 0.18−0.99, p = 0.04, respectively), whereas episodic therapy was positively associated with both outcomes (OR 4.2 95% CI 1.07−16.1, p = 0.04, OR 4.45 95% CI 1.2−16.6, p = 0.026 respectively). All other variables, including IBD type, gender, weight, age, smoking status and disease duration, were not predictive of ATI formation or clinical failure. However, among Crohns disease patients, a non-stricturing non-penetrating phenotype was protective against ATI formation (OR 0.4, 95% CI 0.14−0.96, p = 0.04). P = 0.04, respectively), whereas episodic/interrupted therapy was positively associated with both outcomes (OR 4.2, 95% CI 1.07–16.1, P = 0.04; OR 4.45, 95% CI 1.2–16.6, P = 0.026, respectively). All other variables, including IBD type, sex, weight, age, smoking status, and disease duration, were not predictive of ATI formation or clinical failure. However, among Crohn disease patients, a nonstricturing nonpenetrating phenotype was protective against ATI formation (OR 0.4, 95% CI 0.14–0.96, P = 0.04).Jewish Ashkenazi ethnicity is protective of ATI formation and infliximab therapy failure. These findings suggest a role for ethnicity, and implicitly for genetic predisposition, in modulating the risk of anti-TNF immunogenicity and treatment unresponsiveness.