Assessing response and loss of response to biological therapies in IBD

Vedolizumab provides clinical benefit over 1 year in patients with active inflammatory bowel disease - a prospective multicenter observational study

BACKGROUND

Vedolizumab, a monoclonal antibody targeting the α4β7-integrin, is effective in inducing and maintaining clinical remission in Crohn's disease and ulcerative colitis according to randomised clinical trials.

AIM

To determine the long-term effectiveness of vedolizumab in a real-world clinical setting.

METHODS

This observational registry assessed the clinical outcome in patients treated with vedolizumab for clinically active Crohn's disease (n = 67) or ulcerative colitis (n = 60). Primary endpoint was clinical remission (HBI ≤ 4/pMayo ≤ 1) at week 54. Secondary endpoints included clinical response rates (HBI/pMayo score drop ≥3) and steroid-free clinical remission at weeks 30 and 54.

RESULTS

Vedolizumab was stopped in 69/127 (56%) patients after a median time of 18 weeks (range 2-49) predominantly owing to lack or loss of response. Using nonresponder imputation analysis, clinical remission and steroid-free remission rates were 21% and 15% in Crohn's disease and 25% and 22% in ulcerative colitis, respectively. Lack of clinical remission was associated with prior treatment with anti-TNF or with steroids for more than 3 months in the last 6 months in ulcerative colitis. At week 14, the absence of remission in Crohn's disease or nonresponse in ulcerative colitis indicated a low likelihood of clinical remission at week 54 [2/31 (7%) in Crohn's disease, 4/41 (10%) in ulcerative colitis]. Accordingly, declining C-reactive protein in inflammatory bowel disease and/or lower faecal calprotectin in ulcerative colitis at week 14 predicted remission at week 54.

CONCLUSION

Among patients who started vedolizumab for active inflammatory bowel disease, clinical remission rates are 21-25% after 54 weeks.

Differential cellular localization of Epstein-Barr virus and human cytomegalovirus in the colonic mucosa of patients with active or quiescent inflammatory bowel disease

The role of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) in the exacerbation of inflammatory bowel disease (IBD) is still uncertain. We prospectively investigated the presence of EBV and HCMV infection in both epithelial and immune cells of colonic mucosa of IBD patients, both refractory and responders to standard therapies, in comparison with patients suffering from irritable bowel syndrome who were considered as controls, by using quantitative real-time polymerase chain reaction, immunohistochemistry and in situ hybridization, in an attempt to assess viral localization, DNA load, life cycle phase and possible correlation with disease activity indexes. We obtained clear evidence of the presence of high DNA loads of both viruses in either enterocytes or immune cells of refractory IBD patients, whereas we observed low levels in the responder group and an absence of detectable copies in all cell populations of controls. Remarkably, the values of EBV and HCMV DNA in inflamed mucosa were invariably higher than in non-inflamed areas in both IBD groups, and the EBV DNA loads in the cell populations of diseased mucosa of refractory IBD patients positively correlated with the severity of mucosal damage and clinical indexes of activity. Moreover, EBV infection resulted the most prevalent either alone or in combination with HCMV, while immunohistochemistry and in situ hybridization did not allow us to distinguish between the different phases of viral life cycle. Finally, as regards treatment, these novel findings could pave the way for the use of new antiviral molecules in the treatment of this condition.

Detection of anti-infliximab antibodies is impacted by antibody titer, infliximab level and IgG4 antibodies: a systematic comparison of three different assays

BACKGROUND

There is scant information on the accuracy of different assays used to measure anti-infliximab antibodies (ADAs), especially in the presence of detectable infliximab (IFX). We thus aimed to evaluate and compare three different assays for the detection of IFX and ADAs and to clarify the impact of the presence of circulating IFX on the accuracy of the ADA assays.

METHODS

Blood samples from 79 ulcerative colitis (UC) patients treated with infliximab were assessed for IFX levels and ADAs using three different assays: an in-house assay and two commercial kits, Immundiagnostik and Theradiag. Sera samples with ADAs and undetectable levels of IFX were spiked with exogenous IFX and analyzed for ADAs.

RESULTS

The three assays showed 81-96% agreement for the measured IFX level. However, the in-house assay and Immundiagnostik assays detected ADAs in 34 out of 79 samples, whereas Theradiag only detected ADAs in 24 samples. Samples negative for ADAs with Theradiag, but ADA-positive in both the in-house and Immundiagnostik assays, were positive for IFX or IgG4 ADAs. In spiking experiments, a low concentration of exogenous IFX (5 µg/ml) hampered ADA detection with Theradiag in sera samples with ADA levels of between 3 and 10 µg/ml. In the Immundiagnostik assay detection interference was only observed at concentrations of exogenous IFX higher than 30 µg/ml. However, in samples with high levels of ADAs (>25 µg/ml) interference was only observed at IFX concentrations higher than 100 µg/ml in all three assays. Binary (IFX/ADA) stratification of the results showed that IFX+/ADA- and IFX-/ADAs+ were less influenced by the assay results than the double-positive (IFX+/ADAs+) and double-negative (IFX-/ADAs-) combination.

CONCLUSIONS

All three methodologies are equally suitable for measuring IFX levels. However, erroneous therapeutic decisions may occur when patients show double-negative (IFX-/ADAs-) or double-positive (IFX+/ADAs+) status, since agreement between assays is significantly lower in these circumstances.

Association between serum adalimumab concentrations and endoscopic disease activity in patients with Crohn's disease

BACKGROUND AND AIMS

The serum trough level of adalimumab (ADA) associated with mucosal healing (MH) remains unclear. Our objective was to determine the association between ADA trough levels and the endoscopic activity in Crohn's disease.

MATERIALS AND METHODS

This was a cross-sectional study including 42 patients with Crohn's disease. Endoscopic activity was assessed using the modified Rutgeerts scoring system. The primary outcome was mucosal healing, and the secondary outcomes were serum levels of C-reactive protein and albumin.

RESULTS

Endoscopic disease activity negatively correlated with serum ADA trough levels (Spearman's rank correlation coefficient (ρ) = -0.42, P < 0.01). MH was achieved in 14 of 42 patients (33.3%). Serum ADA trough levels were significantly higher in the MH group than in the no-MH group (ADA mean trough level, 11.7 vs 7.5 µg/mL). The proportion of patients with ADA as the first biologic was significantly higher in the MH group than in the no-MH group (85.7% vs 53.5%, P = 0.04). The ADA trough levels that were best associated with normal C-reactive protein and albumin levels were 5.57 µg/mL (odds ratio [OR] 16.0, specificity 0.80) and 6.95 µg/mL (OR 9.2, specificity 0.81), respectively. The ADA trough level that was best associated with MH was 7.9 µg/mL (OR 13.5, specificity 0.86). The endoscopic disease activity was significantly higher in the patients with ADA as the second biologic as compared with those with ADA as the first biologic (P < 0.05).

CONCLUSION

Mucosal healing requires higher ADA trough levels, compared with those required to normalization of routine clinical markers.

Adalimumab for Treatment of Noninfectious Uveitis: Immunogenicity and Clinical Relevance of Measuring Serum Drug Levels and Antidrug Antibodies

PURPOSE

To evaluate the rate of immunogenicity induced by adalimumab and its relationship with drug serum levels and clinical responses in patients with noninfectious uveitis.

DESIGN

Prospective observational study.

PARTICIPANTS

Consecutive patients from 1 referral center who initiated treatment with adalimumab for active noninfectious uveitis resistant to conventional therapy.

METHODS

All patients received 40 mg adalimumab every other week. Patients were evaluated clinically and immunologically before and after 4, 8, and 24 weeks of treatment.

MAIN OUTCOME MEASURES

Clinical evaluation included assessment of changes in visual acuity, degree of inflammation in the anterior chamber and vitreous cavity, central macular thickness, and retinal angiographic leakage. Immunologic evaluation included assessment of serum trough adalimumab and antibodies against adalimumab (AAA) levels and class II HLA typing.

RESULTS

Twenty-five patients were enrolled. Overall, 18 of 25 patients (72%) showed a favorable clinical response to adalimumab therapy. Eleven patients (44%) achieved a complete response and 7 (28%) achieved a partial response. However, 7 of 25 patients (28%) were considered nonresponders. Median trough adalimumab serum levels were higher in responders than in nonresponders (P < 0.001). We observed AAA positivity (AAA+) at least 1 time point in 8 of 25 patients (32%), including 4 with transitory AAA and 4 with permanent AAA. In all patients with permanent AAA+, trough adalimumab levels became undetectable (P < 0.001). However, in patients who demonstrated transitory AAA+, no correlation was observed between AAA titers and adalimumab trough levels (P = 0.2).Concomitant immunosuppression did not show any protective effect on adalimumab immunogenicity in our cohort. An association between the presence of AAA+ and a worse uveitis outcome was observed only in patients with permanent AAA+, which correlated with undetectable adalimumab trough levels (P = 0.014).

CONCLUSIONS

Treatment of noninfectious uveitis with adalimumab is associated with high rates of favorable clinical response. Overall, adalimumab trough levels were higher in responder patients. Development of permanent AAA was associated with undetectable trough adalimumab levels and worse uveitis outcome. Immunogenicity was more common in patients in whom uveitis was associated with a systemic disease and was not influenced by concomitant immunosuppressors.

Standardization of the homogeneous mobility shift assay protocol for evaluation of anti-infliximab antibodies. Application of the method to Crohn's disease patients treated with infliximab

BACKGROUND

The availability of a quantitative method to measure anti-infliximab (IFX) antibodies (ATI) would facilitate the implementation of therapeutic drug monitoring in clinical decision-making. Our aim was to standardize the homogeneous mobility shift assay (HMSA) used in the measure of ATI levels.

METHODS

In this prospective longitudinal multicenter study, 50 IFX-treated Crohn's disease (CD) patients were followed up for 54weeks. During this period 360 human serum samples were analysed. Monomeric ATI levels were measured by a quantitative HMSA-method using an anti-IFX calibrator. IFX trough levels measured by ELISA were correlated with ATI levels.

RESULTS

Using HMSA and a pure anti-idiotypic monoclonal antibody specific for IFX (anti-IFX calibrator), we measured the levels of monomeric ATI generated in Crohn's disease patients treated with IFX. Anti-IFX calibrator allowed to quantify monomeric antibodies against IFX with a low limit of quantification (3nM). The threshold level of ATI in order to classify the immunogenicity of the patients was 10nM. We observed that 24% (12/50) of IFX-treated patients developed ATI (>10nM) during the observation period (54weeks). Serum concentration of ATI higher than 10nM dramatically increased the probability (OR=51.1; 95% CI: 20.4-128.0; p<0.0001) of presenting low levels of IFX (⩽1.5nM) in serum, as observed in some CD patients treated with standard doses of the drug.

CONCLUSIONS

The HMSA-method described here allows an accurate quantification of ATI concentration in international units (IU) and therefore it could be useful in the study of the relationship between ATI concentration, infliximab level and the clinical response to the drug.

Immunogenicity Assessment of Tumor Necrosis Factor Antagonists in the Clinical Laboratory

BACKGROUND

Tumor necrosis factor (TNF) antagonists are increasingly used for the treatment of inflammatory and autoimmune diseases. Immunogenicity of these drugs poses therapeutic challenges such as therapeutic failure and adverse effects in a number of patients. Evaluation of clinical nonresponsiveness includes laboratory testing for drug concentrations and detecting the presence of antidrug antibodies.

CONTENT

This review provides an overview of the immunogenicity of TNF antagonists and testing methodologies currently available for measuring antidrug antibody response, which decreases treatment efficacy and may result in therapeutic failure. This review summarizes methodologies such as binding assays, including ELISA and HPLC-based homogenous mobility shift assay, as well as functional cell-based assays such as reporter gene assay. Furthermore, based on the laboratory findings of testing for antidrug antibody response, as well as serum drug concentrations, an algorithm is provided for interpretation, based on the current available literature and guidelines, which may aid in determining optimal therapy after treatment failure.

SUMMARY

Laboratory testing methodologies for measuring serum concentrations of TNF inhibitors and antidrug antibodies are clinically available. These methods provide an evidence-based, personalized approach for the workup of patients showing treatment failure, which saves time and resources, and contributes to improved patient care.

Adalimumab trough serum levels and anti-adalimumab antibodies in the long-term clinical outcome of patients with Crohn's disease

OBJECTIVE

Few data are available on the relevance of adalimumab (ADA) trough serum levels and anti-ADA antibodies (AAA) during long-term follow-up of patients with Crohn's Disease (CD), and their association with disease outcome. In this study, our aim was to assess ADA trough serum levels and the presence of AAA according to disease activity and clinical response during long-term follow-up in a series of patients with CD treated with ADA monotherapy.

MATERIAL AND METHODS

We prospectively evaluated 23 consecutive, infliximab-naïve CD patients who achieved clinical remission/response after induction and were in maintenance treatment with ADA, and who were followed-up for at least 72 weeks. Blood samples were drawn at standardized time points to assess ADA through levels, AAA.

RESULTS

At week 48, we found significantly (p = 0.027) different ADA trough serum levels in patients in remission (10.1 mcg/mL), mild (7.4 mcg/mL), and moderate/severe disease (4.5 mcg/mL). Median ADA trough levels were significantly lower in patients with AAA (3.7 mcg/mL versus 9.3 mcg/mL, p = 0.006). At the end of follow-up (median 102 weeks, range 73-112 weeks), ADA trough serum concentrations were significantly higher (11.9 mcg/mL) as compared to patients with mild and moderate/severe disease (5.5 mcg/mL, p = 0.0002). Furthermore, median ADA trough concentrations showed a trend towards lower levels in AAA positive patients (5.2 mcg/mL versus 7.2 mcg/mL, p = 0.371).

CONCLUSIONS

Our results emphasize the relevance of therapeutic drug monitoring in CD patients on biologic treatment. ADA trough serum levels and the presence of AAA are important features in the management of patients on ADA treatment.

Prediction of clinical and endoscopic responses to anti-tumor necrosis factor-α antibodies in ulcerative colitis

Objective In patients with ulcerative colitis (UC), the relationship between the initial endoscopic findings and the response to anti-tumor necrosis factor (TNF)-α antibodies remains unclear. We herein evaluated the potential of endoscopic assessment using the ulcerative colitis endoscopic index of severity (UCEIS) to predict the response to anti-TNF-α antibodies. Methods We enrolled 64 patients with UC undergoing anti-TNF-α maintenance therapy with infliximab (IFX) or adalimumab (ADA) between April 2010 and March 2015. Anti-TNF-α trough levels were determined by ELISA. Endoscopic disease activity was assessed using the UCEIS. Results The clinical response rate at 8 weeks was 77.4% for IFX and 66.7% for ADA. Serum albumin levels were significantly higher and the UCEIS bleeding descriptor before treatment was significantly lower in the responders than in the non-responders (p < 0.05 each). The CRP levels at 2 weeks were significantly lower in the responders (p < 0.001). The serum albumin levels before treatment were significantly higher and the UCEIS erosions and ulcers descriptor was significantly lower in the mucosal healing group than in the non-mucosal healing group (p < 0.05 each). A significant and negative correlation between the trough levels of anti-TNF-α antibodies and the UCEIS descriptors was observed. The trough levels of anti-TNF-α antibodies to achieve mucosal healing were 2.7 μg/mL for IFX and 10.3 μg/mL for ADA. Conclusions The UCEIS score, as well as some clinical markers (serum albumin and CRP levels), is useful for the prediction of the treatment outcome of UC patients in response to anti-TNF-α antibodies.

Optimizing Treatment with TNF Inhibitors in Inflammatory Bowel Disease by Monitoring Drug Levels and Antidrug Antibodies

BACKGROUND

Biological tumor necrosis factor (TNF) inhibitors have revolutionized the treatment of inflammatory bowel disease and redefined treatment goals to include mucosal healing. Clinicians are faced with challenges such as inadequate responses, treatment failures, side effects, and high drug costs. The objective is to review optimization of anti-TNF therapy by use of personalized treatment strategies based on circulating drug levels and antidrug antibodies (Abs), i.e. therapeutic drug monitoring (TDM). Furthermore, to outline TDM-related pitfalls and their prevention.

METHODS

Literature review.

RESULTS

Circulating anti-TNF drug trough level is a marker for the pharmacokinetics (PK) of TNF inhibitors. Because of a number of factors, including antidrug antibodies, PK varies between and within patients across time leading to variable clinical outcomes. Differences in intestinal inflammatory phenotype influencing the pharmacodynamic (PD) responses to TNF inhibitors also affect treatment outcomes. As an alternative to handling anti-TNF-treated patients by empiric strategies, TDM identifies underlying PK and PD-related reasons for treatment failure and aids decision making to secure optimal clinical and economic outcomes. Although promising, evidence does not the support use of TDM to counteract treatment failure in quiescent disease. Use of TDM is challenged by methodological biases, difficulties related to differentiation between PK and PD problems, and temporal biases due to lack of chronology between changes in PK versus symptomatic and objective disease activity manifestations. Biases can be accommodated by knowledgeable interpretation of results obtained by validated assays with clinically established thresholds, and by repeated assessments over time using complimentary techniques.

CONCLUSIONS

TDM-guided anti-TNF therapy at treatment failure has been brought from bench to bedside.

Preventive and curative effect of Pistacia lentiscus oil in experimental colitis

AIM

to investigate the anti-inflammatory effect of the Pistacia lentiscus oil in experimental colitis model.

MATERIALS AND METHODS

Colitis was induced in male rats by instillation of 2,4,6-trinitrobenzenesulfonic acid (TNBS) in all groups. The experimental groups consisted of: 5 rats received Lentisc oil 2months before colitis induction (preventive group), 5 rats received the oil on the day of colitis induction (curative group) and 5 control rats. Lentisc oil was extracted from the ripe fruit of the plant by the cold press method and was analyzed by spectro-chromatography. Lentisc oil has been inserted with a standard diet at the dose of 30mg oil/100g of food/rat.

RESULTS

The lentisc oil sample is composed mainly by Oleic acid (47.96%), Palmitic acid (27.94%) and Linoleic acid (20.22%).There was a significant difference between control rats and treated rats with lentisc oil concerned body mass (p=0.009), bleeding index (p=0.005 and p=0.018) and diarrhea (p=0.012). Histological examination revealed a clear difference between the control and preventive groups with disappearance of erosion, decreased of cryptitis, irregular crypts and crypt loss in the preventive group. Curative group showed a significant decrease of ulceration, hyperplasia, cryptitis, irregular crypts and crypt loss compared to the control group. There was an attenuation of inflammation in the preventive group compared to the curative group without statistically significant.

CONCLUSION

Lentisc oil administration could provide a protective effect on intestinal inflammation in colitis rats induced by TNBS mainly when it is administered at a young age in preventive mode. This beneficial effect would involve a modification of arachidonic acid metabolism.

Ustekinumab in Crohn's disease: evidence to date and place in therapy

Crohn's disease (CD) is an inflammatory bowel disease (IBD) with uncertain etiology. Biologic agents have revolutionized the treatment of CD but nonresponders remain a challenge. Ustekinumab is an interleukin 12/23p40 inhibitor that was recently found effective in treating CD. We reviewed the current literature regarding the efficacy of ustekinumab in treating CD and concluded that ustekinumab is a novel, promising and relatively safe agent for the treatment of moderate to severe CD. Additional data from randomized controlled studies and real-life cohorts are pending.

Predicting durable response or resistance to antitumor necrosis factor therapy in inflammatory bowel disease

Monoclonal antibodies to tumor necrosis factor (TNF) have become a mainstay of the therapeutic armamentarium in inflammatory bowel disease (IBD) over the last 15 years. Although highly effective, primary and secondary nonresponse are common and associated with poor clinical outcomes and significant costs. Multiple clinical, genetic and immunopharmacological factors may impact the response to anti-TNFs. Early stratification of IBD patients by the expected risk of therapeutic failure during the induction and maintenance phases of treatment may allow for treatment optimization and potentially optimal short- and long-term outcomes. The aim of this review is to summarize the current data concerning the potential predictors of therapeutic success and failure of anti-TNFs in IBD.

Anti-infliximab Antibodies with Neutralizing Capacity in Patients with Inflammatory Bowel Disease: Distinct Clinical Implications Revealed by a Novel Assay

BACKGROUND

About 60% of infliximab (IFX)-treated patients develop antidrug antibodies (ADA), although their clinical significance remains disputed. The aim of this study was to develop an assay for assessing ADA-neutralizing potential, and clinical significance.

METHODS

An immune assay was devised in which the inhibition of IFX binding to plated-tumor necrosis factor in the presence of patient sera or controls, was assessed and defined as IFX-tumor necrosis factor binding reduction ratio (ITBR). The assay was compared to a bioassay in which tumor necrosis factor-α-induced interleukin-8 secretion from HT-29 cells was assessed after addition of IFX to ADA-containing sera or control sera.

RESULTS

Both assays detected neutralizing antibodies in 39 of 44 ADA-positive sera. The median ITBR was 3.66 (mean 4.9 ± 3.2) in 29 ADA-positive patients with loss of response (LOR), and 1.3 (mean 1.9 ± 1.3) in 15 patients without LOR (P = 0.001). ADA titers in both groups were similar (median 9.5 and 10.2 μg/mL, respectively P = 0.74). Using an ITBR of 1.65, the sensitivity for LOR detection was 86.2% and the specificity was 66.7%. (positive predictive value 83%; negative predictive value 71.4%; P = 0.001). When early ADA-IFX-sera from IFX-treated patients with or without subsequent LOR were compared, the median ITBRs were 1.1 and 0.57, respectively (P = 0.028).

CONCLUSIONS

Detection of neutralizing antibody activity was superior to antibody quantization by enzyme-linked immunosorbent assay with respect to correlation with clinical LOR, and for prediction of subsequent LOR. These findings may assist in optimizing infliximab therapy in patients with inflammatory bowel disease.

Adalimumab Treatment in Pediatric-Onset Crohn's Disease Patients after Infliximab Failure: A Single Center Study

PURPOSE

We aimed to investigate the efficacy and safety of adalimumab in pediatric-onset Crohn's disease patients who had failed treatment with infliximab.

METHODS

In this retrospective study, patients included were those who had been diagnosed with Crohn's disease before 18 years old, and had received treatment with adalimumab after infliximab failure. The efficacy of adalimumab treatment was investigated at 1 month and 1 year, and adverse events that had occurred during treatment with adalimumab were explored.

RESULTS

Ten patients were included in this study. The median duration from diagnosis to adalimumab treatment was 5.5 years (range: 2.4-7.9 years). At 1 month after adalimumab initiation, 80% (8/10) of patients showed clinical response, and 40% (4/10) achieved clinical remission. At 1 year, 71% (5/7) of patients showed clinical response, and 43% (3/7) were under clinical remission. Among the total included patients, 5 patients (50%) showed clinical response at 1 year. Primary non-response to adalimumab was observed in 2 patients (20%), and secondary failure to adalimumab was observed in 3 patients (30%) during 1 year treatment with adalimumab. No serious adverse event had occurred during adalimumab treatment.

CONCLUSION

Adalimumab was effective for 1 year without serious adverse events in half of pediatric-onset Crohn's disease patients who had failed treatment with infliximab.

Alterations to chromatin in intestinal macrophages link IL-10 deficiency to inappropriate inflammatory responses

Intestinal macrophages (IMs) are uniquely programmed to tolerate exposure to bacteria without mounting potent inflammatory responses. The cytokine IL-10 maintains the macrophage anti-inflammatory response such that loss of IL-10 results in chronic intestinal inflammation. To investigate how IL-10-deficiency alters IM programming and bacterial tolerance, we studied changes in chromatin accessibility in response to bacteria in macrophages from two distinct niches, the intestine and bone-marrow, from both wild-type and IL-10-deficient (Il10(-/-) ) mice. We identified chromatin accessibility changes associated with bacterial exposure and IL-10 deficiency in both bone marrow derived macrophages and IMs. Surprisingly, Il10(-/-) IMs adopted chromatin and gene expression patterns characteristic of an inflammatory response, even in the absence of bacteria. Further, when recombinant IL-10 was added to Il10(-/-) cells, it could not revert the chromatin landscape to a normal state. Our results demonstrate that IL-10 deficiency results in stable chromatin alterations in macrophages, even in the absence of bacteria. This supports a model in which IL-10-deficiency leads to chromatin alterations that contribute to a loss of IM tolerance to bacteria, which is a primary initiating event in chronic intestinal inflammation.

Higher Adalimumab Drug Levels are Associated with Mucosal Healing in Patients with Crohn's Disease

BACKGROUND AND AIMS

The current approach to managing the loss of response to anti-tumour necrosis factor (TNF) agents is generally empirical. Prior studies have suggested that adalimumab levels of >4.9 µg/mL are required to achieve clinical remission. Our aim was to identify an optimal adalimumab level to achieve endoscopic healing in Crohn's disease (CD).

METHODS

A cohort of 60 CD patients treated with adalimumab between 2005 and 2013 were reviewed for the study. Demographic and clinical information was obtained from chart review and patient interview. Disease activity was determined using the Harvey-Bradshaw index (HBI), ileocolonoscopy reports and C-reactive protein (CRP) levels. Clinical remission was defined as HBI <5. Endoscopic remission/mucosal healing (MH) was defined as the absence of any ulceration in all ileocolonic segments. Trough adalimumab levels and adalimumab antibody levels were tested using a liquid-phase mobility shift assay.

RESULTS

Lower median CRP was significantly associated with MH 1.2mg/dl vs no MH 14.4mg/dl (p = 6.93×10(-6)). Higher adalimumab trough level was significantly associated with MH (median 14.7 µg/mL in those with MH vs 3.4 µg/mL in those without, p = 6.25×10(-5)). Higher adalimumab trough level was also significantly associated with the combined outcome of clinical and endoscopic remission (median 13.0 vs 4.8 µg/mL, p = 5.36×10(-3)). A cut-off of 8.14 µg/ml best discriminated subjects with MH from those without MH, with sensitivity and specificity of 91.4 and 76.0%, respectively (positive and negative predictive values 84.2 and 86.4%, respectively).

CONCLUSIONS

Higher adalimumab levels were significantly associated with MH. This study suggests that attaining MH alone or a combined outcome of clinical and endoscopic remission is more likely to occur in those patients who achieve an adalimumab trough level of at least 8.14 μg/mL.

Experience With Anti-TNF-α Biologic Agents in Succession in Patients With Crohn's Disease: A Retrospective Analysis of a Single Center

GOALS

Our aim was to identify and compare the effectiveness of antitumor necrosis factor biologics when used as initial agents and when used in succession for the treatment of moderate to severe Crohn's disease (CD).

BACKGROUND

Studies directly comparing the efficacy of biologics are lacking. When one biologic loses efficacy, patients are often treated with an alternate biologic. The effectiveness of this strategy has not been thoroughly investigated.

STUDY

This is a retrospective cohort study from a database of 153 patients with CD treated with infliximab, adalimumab, or certolizumab pegol. Response rates determined by physician global assessment were compared between biologics when given as initial agents and after failure of 1 or 2 prior biologics.

RESULTS

There were no significant differences in response between infliximab (64.5%), adalimumab (60.0%), and certolizumab pegol (66.7%) when given as initial biologics. As second-line or third-line agents after prior biologic failure, there was a trend toward increased response with infliximab (83.3%) versus adalimumab (52.7%) and certolizumab pegol (59.4%); however, this did not meet statistical significance. After failure or loss of response of 2 previous biologics, use of a third biologic was still effective with a response rate of 54.2%.

CONCLUSIONS

All 3 biologics have similar efficacy in the treatment of CD when given as initial agents. Infliximab has a trend toward increased response after prior biologic failure; however, this did not meet statistical significance. Even after loss of response or failure of 2 previous biologics, trial of a third alternate biologic is an effective strategy.

Harmonization of Infliximab and Anti-Infliximab Assays Facilitates the Comparison Between Originators and Biosimilars in Clinical Samples

BACKGROUND

The availability of an infliximab ELISA for measuring the originator drug Remicade and its biosimilars, such as Remsima and Inflectra (CT-P13), would facilitate the implementation of therapeutic drug monitoring of biosimilars and enhance the extrapolation of treatment stratification algorithms established for Remicade. A universal calibrator for all anti-infliximab antibody bridging assays allows harmonization of anti-drug antibody titers.

METHODS

A panel of 55 mouse monoclonal antibodies raised against Remicade, including MA-IFX6B7 and MA-IFX10F9, were evaluated for their reactivity toward the biosimilars using a sandwich-type ELISA and surface plasmon resonance. To analyze the similarity of detection of the biosimilars and Remicade in the infliximab ELISA, quality control samples were used. Bridging assays to determine anti-infliximab antibodies were developed according to the bridging ELISA of Remicade using MA-IFX10F9 as calibrator. Serum of 36 patients treated with Remicade was analyzed for anti-infliximab antibodies toward Remicade, Remsima and Inflectra using their respective bridging ELISA.

RESULTS

MA-IFX6B7 and MA-IFX10F9 exhibit equal reactivity toward Remicade, Remsima, and Inflectra. The infliximab ELISA quantifies the biosimilars equally well as Remicade. Quantification of anti-infliximab antibodies in the serum of patients treated with Remicade revealed highly correlated titers between biosimilars and Remicade.

CONCLUSIONS

The assay for therapeutic drug monitoring of Remicade can also be used to determine Remsima and Inflectra concentrations. Anti-drug antibody assays for biosimilars were developed. Anti-Remicade antibodies cross-react with infliximab biosimilars and reveal consistent negative/positive anti-drug antibody responses and highly correlated titers.

Comparative analysis of the influence of clinical factors including BMI on adalimumab and infliximab trough levels

INTRODUCTION

Optimal trough levels of the anti-tumour necrosis factor agents, infliximab and adalimumab, are correlated with clinical remission. Obesity adversely affects response to infliximab and adalimumab, but the influence of BMI on trough levels has not been adequately investigated. We investigated the relationship between clinical variables, including BMI, and trough levels of infliximab and adalimumab.

METHODS

This prospective cross-sectional study included patients treated with infliximab and adalimumab on maintenance therapy, with concurrent measurements of trough levels and BMI. The associations between categorical trough levels and clinical variables, including BMI, were estimated.

RESULTS

Of the 122 patients included in the study, 80 (66%) were on infliximab and 42 (34%) were on adalimumab. Eighty-three per cent had Crohn's disease and the remainder had ulcerative colitis. None of the clinical variables, including smoking, BMI, concurrent immunosuppression, duration of disease and treatment, were associated with categorical trough levels of infliximab or adalimumab. The effect of BMI did not differ between the two anti-tumour necrosis factor agents, although there was a trend towards a lower trough level in adalimumab-treated patients with a BMI greater than 30 (P=0.09). In infliximab-treated patients, antibodies to infliximab (P<0.001) and a C-reactive protein level of at least 5 mg/dl were associated with trough levels less than 3 µg/ml (P=0.008).

CONCLUSION

BMI does not differentially influence trough levels of adalimumab and infliximab, although a trend towards a lower trough level was observed in adalimumab-treated patients with a BMI greater than 30. Raised C-reactive protein levels and antibodies to infliximab were associated with subtherapeutic levels of infliximab.

Adrenomedullin Therapy in Patients with Refractory Ulcerative Colitis: A Case Series

BACKGROUND AND AIMS

Adrenomedullin (AM) is a multifunctional biologically active peptide that has an ameliorative effect against inflammatory bowel disease in several experimental models. We reported the first case where AM infusion dramatically improved symptoms and colonoscopy findings in patients with refractory ulcerative colitis (UC). To confirm the reproducibility of the efficacy and safety of AM infusion, this pilot study evaluated the clinical feasibility of intravenous administration of AM in patients with refractory UC.

METHODS

Seven patients with active refractory UC participated and received intravenous infusion of AM (1.5 pmol/kg/min) for 8 h daily for 14 days, and their Disease Activity Index (DAI) were evaluated before and 2 and 12 weeks after beginning AM administration.

RESULTS

DAI were improved in all patients after AM administration. Within 2 weeks, marked declines in DAI (≥ 3 points and ≥ 30%) were observed in six patients (85.7%), while a more modest decline was observed in one patient (14.3%). Overall mean DAI improved from 9.3 ± 0.6 at baseline to 4.6 ± 0.8 at 2 weeks, and then to 1.2 ± 0.5 at 12 weeks. Endoscopic examination revealed substantial amelioration of ulcers, with mucosal healing and scarring. Four patients remained in clinical remission 12 months after AM treatment. AM administration produced significant increases in plasma AM concentrations (approximately 2.5-fold) that had a mild effect on blood pressure and heart rate, but with no serious adverse effects.

CONCLUSION

AM is a potentially useful agent that acts via a novel mechanism to safely induce mucosal healing and clinical remission in patients with refractory UC.

Bioelectrical Stimulation for the Reduction of Inflammation in Inflammatory Bowel Disease

Crohn's disease and ulcerative colitis are the primary inflammatory bowel diseases (IBDs) affecting the gastrointestinal tract. The current therapy aims at decreasing inflammation and reducing symptoms. This typically requires immune suppression by steroids, thiopurines, methotrexate, or tumor necrosis factor inhibitors. Patients may be unreceptive to medical therapy, and some may discontinue the treatment due to adverse effects. Noninvasive, transcutaneous vagus nerve stimulation (VNS) is currently used as a treatment for depression and epilepsy, and it is being investigated for the treatment of conditions such as multiple sclerosis, migraines, and Alzheimer's disease. Recent studies have demonstrated the importance of splenic and vagus nerve functions in the inflammatory process through the production of certain cytokines. We hypothesize that using transcutaneous VNS via the auricular afferent branch could achieve a selective anti-inflammatory effect on the intestinal wall. This review examines the possibility of using vagal stimulators as a therapy for IBD. This could open the door to novel treatments for numerous vagally mediated diseases characterized by poor responses to current therapies.

Current stage in inflammatory bowel disease: What is next?

In recent years, the incidence of inflammatory bowel disease (IBD) has been on the rise, extending to countries where it was infrequent in the past. As a result, the gap between high and low incidence countries is decreasing. The disease, therefore, has an important economic impact on the healthcare system. Advances in recent years in pharmacogenetics and clinical pharmacology have allowed for the development of treatment strategies adjusted to the patient profile. Concurrently, new drugs aimed at inflammatory targets have been developed that may expand future treatment options. This review examines advances in the optimization of existing drug treatments and the development of novel treatment options for IBD.

Genetic Polymorphisms of IL-17F and TRAF3IP2 Could Be Predictive Factors of the Long-Term Effect of Infliximab against Crohn's Disease

Background. We aimed to identify certain genes related to response to infliximab (IFX) and biomarkers to predict the IFX effect for Japanese Crohn's disease (CD) patients by performing an association study of single nucleotide polymorphisms (SNPs) in candidate genes in the interleukin- (IL-) 17 signaling pathway with response to IFX after 1 year of treatment. Methods. A total of 103 patients were divided into two groups, responders and nonresponders. Twenty-eight tag SNPs in 5 genes were genotyped. The frequencies of alleles and genotypes of each SNP were compared between responders and nonresponders in three different inheritance models. A genetic test was performed using a combination of the associated SNPs as biomarkers. Results. Multivariate logistic regression analysis indicated that the four variable factors, concomitant use of immunomodulators, penetrating disease, a G/G genotype of rs766748 in IL-17F, and a C/C or C/A genotype of rs1883136 in TRAF3IP2, independently contributed to response to IFX after 1 year of treatment. Genetic test using the polymorphisms of these genes perfectly predicted the responder and nonresponder CD patients with both concomitant use of immunomodulators and penetrating disease. Conclusion. IL17F and TRAF3IP2 are one of IFX-related genes, useful as biomarkers of IFX response, and may be target molecules for new therapeutic drugs.

Therapeutic strategy for Crohn's disease with a loss of response to infliximab: a single-center retrospective study

BACKGROUND/AIMS

Infliximab (IFX) is an effective treatment for maintaining clinical remission in patients with initially moderate-to-severe Crohn's disease (CD). However, a certain number of patients become unresponsive to IFX, subsequently requiring intensified therapy. The aim of this study was to compare the short- and long-term therapeutic efficacy of intensified regimens in CD patients who fail to respond to IFX.

METHODS

The clinical courses of 33 CD patients who failed to respond to treatment with IFX were investigated retrospectively. An intensified regimen involving doubling the dose of IFX was chosen in 13 patients (DD group) versus shortening the IFX interval in 13 patients (SI group) and switching to adalimumab (ADA) in 7 patients (SA group).

RESULTS

The clinical response and rate of clinical remission at 4 weeks were 62 and 54% in the DD group, 77 and 62% in the SI group and 57 and 43% in the SA group, respectively (p = 0.59 for clinical response, p = 0.90 for clinical remission). The rate of sustained remission at 48 weeks was 44% in the DD group, 54% in the SI group and 33% in the SA group (p = 0.88).

CONCLUSION

The short- and long-term efficacy of doubling the dose of IFX, shortening the interval of IFX or switching to ADA is similar for CD patients who no longer respond to IFX.

Recommendations for managing a suboptimal response to biologics for moderate-to-severe psoriasis: A Belgian perspective

Over the past decade, biologics have become the gold standard in the treatment of moderate-to-severe psoriasis for patients who have failed or who have contraindications to traditional systemic treatments. However, although practical recommendations on how to treat a suboptimal response to biologics exist in other chronic inflammatory diseases, they are only just beginning to emerge for psoriasis. This article aims to formulate recommendations in the case of a suboptimal response of psoriasis to biologics in the Belgian setting. A Belgian taskforce of psoriasis experts was convened to review the results of a literature search and formulate recommendations based on the available evidence and provide expert opinion to address gaps in the evidence. The taskforce has proposed a treatment algorithm for patients with a primary non-response or a secondary loss of response to help address an unmet need. Expert recommendations have been developed to address treatment strategies in case of a primary or secondary suboptimal response to biologics in the treatment of moderate-to-severe psoriasis in Belgium.

The Role of Therapeutic Drug Monitoring of Anti-Tumor Necrosis Factor Alpha Agents in Children and Adolescents with Inflammatory Bowel Disease

BACKGROUND

Anti-tumor necrosis factor alpha (TNFα) therapy is effective in pediatric patients with inflammatory bowel disease (IBD) but associated with a risk of developing anti-drug antibodies (ADA) which lower the efficacy. Incorporating measurement of trough levels and ADA (therapeutic drug monitoring) may prevent the development of neutralizing ADA or could contribute to more optimal treatment strategies if ADA are already formed. The aim of this review was to investigate the role of therapeutic drug monitoring in children and adolescents with IBD exposed to anti-TNFα agents.

METHODS

A literature search identified publications that measured anti-TNFα drug trough levels and/or ADA in children or adolescents with IBD. Studies were eligible when (1) article was written in English, (2) original data were available, (3) full text article or abstract was available, (4) measurement of antibodies against anti-TNFα drugs or trough level of anti-TNFα drugs were reported, and (5) levels were measured in pediatric patients with IBD.

RESULTS

The search yielded 811 articles, of which 795 articles were excluded based on title or abstract. A total of 14 studies were included in the review.

CONCLUSIONS

Therapeutic drug monitoring within the pediatric IBD population certainly has a potential benefit. As occurrence of immune reactions to anti-TNFα agents varies widely, incorporating measurement of IFX trough levels at week 8 or week 14 predicts therapy response and allows for dose adjustments to reach therapeutic drug concentrations. However, a clinically relevant cutoff level for ADA has not been defined yet, and the optimal intervention strategy still has to be determined.

An Optimized Anti-infliximab Bridging Enzyme-linked Immunosorbent Assay for Harmonization of Anti-infliximab Antibody Titers in Patients with Inflammatory Bowel Diseases

BACKGROUND

The formation of anti-infliximab antibodies (ATI) is associated with loss of response and adverse events in patients with inflammatory bowel diseases, leading to the introduction of ATI monitoring for guiding treatment adjustments. However, a lack of standardization among current available assays exists, hampering comparison of results from different studies. This study aimed to improve the harmonization of clinically validated ATI enzyme-linked immunosorbent assays (ELISAs) by introducing a monoclonal anti-infliximab antibody (MA-IFX).

METHODS

A panel of MA-IFX was evaluated as calibrator in the first generation ATI ELISA. After selection of 1 MA-IFX, assay conditions were optimized and biotin-streptavidin-enhanced detection of bound infliximab was introduced. The novel second generation ELISA was used for reanalysis of 127 serum samples from a cohort of 12 patients with inflammatory bowel disease, previously identified as ATI positive.

RESULTS

Of 55 MA-IFX, MA-IFX10F9 was selected as calibrator in the ATI ELISA. After optimization of the assay conditions, a 4-fold improvement in sensitivity was obtained. Reanalysis of 127 serum samples revealed that in 5 of 12 patients (46%), ATI were detected at least 1 time point earlier with the second generation ELISA compared with the first generation ELISA. In 1 patient, the second generation ELISA allowed to detect ATI before the reinitiation of IFX after a drug holiday.

CONCLUSIONS

In addition to the improved sensitivity and specificity of the second generation ATI ELISA, MA-IFX10F9 can serve as a universal calibrator to achieve assay harmonization. Moreover, the superiority of the second generation assay in analyzing serum of restarters was demonstrated.

Loss of Infliximab Into Feces Is Associated With Lack of Response to Therapy in Patients With Severe Ulcerative Colitis

BACKGROUND & AIMS

It is not clear why some patients with ulcerative colitis (UC) do not respond to treatment with anti-tumor necrosis factor (TNF) agents, such as infliximab. It could be that some patients have high level of inflammation, with large quantities of TNF to be neutralized by the drug. We investigated whether loss of anti-TNF agents through ulcerated intestinal mucosa reduces the efficacy of these drugs in patients with severe UC.

METHODS

We collected fecal samples from 30 consecutive patients with moderate to severely active UC during the first 2 weeks of infliximab therapy at the University of Amsterdam hospital. Infliximab concentrations were measured in serum and supernatants of fecal samples using an enzyme-linked immunosorbent assay (Sanquin Biologicals Laboratory, Amsterdam, The Netherlands). Clinical and endoscopic responses were assessed 2 and 8 weeks and 3 months after treatment began.

RESULTS

Infliximab was detected in 129 of 195 fecal samples (66%); the highest concentrations were measured in the first days after the first infusion. Patients that were clinical nonresponders at week 2 had significantly higher fecal concentrations of infliximab after the first day of treatment than patients with clinical responses (median concentration, 5.01 μg/mL in nonresponders vs 0.54 μg/mL in responders; P = .0047). We did not observe a correlation between fecal and serum concentrations of infliximab.

CONCLUSIONS

Infliximab is lost into stools of patients with UC. High fecal concentrations of infliximab in the first days after therapy begins are associated with primary nonresponse. Additional studies are needed to determine how therapeutic antibodies are lost through the intestinal mucosa and how this process affects treatment response. Clinical trial ID: NL41310.018.12.

Characterizing unmet medical need and the potential role of new biologic treatment options in patients with ulcerative colitis and Crohn's disease: a systematic review and clinician surveys

OBJECTIVES

Comparative outcomes of patients with ulcerative colitis (UC) and Crohn's disease (CD) prescribed a biologic therapy are inconclusive. The aim of this research was to characterize the degree of unmet medical need in patients with UC or CD and to identify the potential role for new therapies.

METHODS

A systematic literature review was undertaken of studies reporting outcomes associated with the use of existing biologic therapies in patients with UC or CD, focusing on the nature and rate of treatment failure. To complement the systematic review, contemporaneous data were obtained from a survey of practising gastroenterologists in the UK and France. Data were qualitatively combined in a narrative framework to evaluate the degree of unmet medical need among patients with UC or CD.

RESULTS

Studies identified in the systematic review (n = 120) were heterogeneous, particularly with respect to the definitions of treatment failure; estimates of treatment failure were high but uncertain. On the basis of standardized definitions, estimates of treatment failure provided by clinicians (n = 102) were high, and they were higher for second-line treatment failure (primary: ≤ 37%; secondary: ≤ 41%) compared with first-line treatment failure (primary: ≤ 26%; secondary: ≤ 28%). The majority of the systematic review and survey data were reflective of outcomes with infliximab and adalimumab.

CONCLUSION

High treatment failure rates associated with existing biologics, identified by the review and clinician surveys, indicate a need for other biologic treatment options to improve the management and outcomes for people with UC and CD. Outcomes associated with existing and new biologic treatments should be investigated in head-to-head randomized trials in the context of their likely uses in clinical practice.

Inflammatory bowel disease meta-evidence and its challenges: is it time to restructure surgical research?

AIM

The aim of this study was to compare the methodological quality and input paper characteristics of systematic reviews and meta-analyses reported in the medical and surgical literature by performing a systematic 'overview of reviews'. Ulcerative colitis (UC) and Crohn's disease (CD) were used as the framework for this comparison as they are relatively common serious conditions, with both medical and surgical options for therapy.

METHOD

Medline, Embase, CINHAL and the Cochrane Database were searched to November 2013. Eligible papers were systematic reviews or meta-analyses that considered a question of therapy in CD or UC. Two independent reviewers selected the papers, extracted the data and scored their methodology using the AMSTAR scoring system. The papers were categorized into medical therapy (M), surgical therapy (S) or medical and surgical therapy (MS) groups. Following retrieval of the sample of meta-evidence papers, the original input studies used in their creation were identified and a search of Medline, Embase, CINHAL and the Cochrane Database was performed. A team of researchers then examined the collection of papers for bibliographic and financial information.

RESULTS

Five hundred papers were identified in the meta-evidence search, of which 118 were deemed eligible. There was a difference in the AMSTAR-rated average quality of the papers between the S and M group (S 7.36 vs M 8.75, P = 0.01). On average S papers were published in journals with a lower impact factor (S 3.26, M 5.04, MS 5.30, P < 0.001). S papers also showed more heterogeneity (I(2) ; S 37%, M 24%, MS 10%, P < 0.001). Some 25% of S meta-analyses used data-sets with significant heterogeneity (I(2) > 75%), compared with 8% of M meta-analyses and 3% of the MS meta-analyses. Some 5% of S papers were done on data sets that had I(2) values > 90%. There was no difference in the average number of papers assessed in each group, the average number of patients per meta-paper, the average time covered by the reviews, the average number of papers considered within each meta-analysis, or the average number of patients considered within each meta-analysis. Considering the conclusions of each meta-analysis, S meta-evidence was 50% more likely than M meta-evidence to be unable to make recommendations for practice. A total of 1499 original input papers were identified, of which 283 were used in more than one review. Within the non-repeated papers (n = 1023) the average impact factor within the S group was lower than that of the M and the MS groups (3.720 vs 11.230 vs 7.563, respectively; ANOVAP < 0.001). M papers had higher rates of pharmaceutical sponsorship than S papers (M 56% vs S 1%) and twice the level of government support (M 16% vs S 8%). Of note, 21% of M papers had corporate sponsorship but did not list any conflict of interest.

CONCLUSION

Compared with M meta-analyses, S meta-analyses in the UC and CD domain are more likely to be of poorer methodological quality, are of a greater degree of heterogeneity and less often offer a positive conclusion. The papers used to generate meta-evidence in M papers have a greater degree of corporate and government sponsorship, and are more likely to come from journals with higher impact factors.

Enhanced colonic delivery of ciclosporin A self-emulsifying drug delivery system encapsulated in coated minispheres

OBJECTIVES

Investigate the potential of coated minispheres (SmPill®) to enhance localized Ciclosporin A (CsA) delivery to the colon.

METHODS

CsA self-emulsifying drug delivery systems (SEDDS) were encapsulated into SmPill® minispheres. Varying degrees of coating thickness (low, medium and high) were applied using ethylcellulose and pectin (E:P) polymers. In vitro CsA release was evaluated in simulated gastric and intestinal media. Bioavailability of CsA in vivo following oral administration to pigs of SmPill® minispheres was compared to Neoral® po and Sandimmun® iv in a pig model. CsA concentrations in blood and intestinal tissue were determined by HPLC-UV.

RESULTS

In vitro CsA release from coated minispheres decreased with increasing coating thickness. A linear relationship was observed between in vitro CsA release and in vivo bioavailability (r(2) = 0.98). CsA concentrations in the proximal, transverse and distal colon were significantly higher following administration of SmPill®, compared to Neoral® po and Sandimmun® iv (p < 0.05). Analysis of transverse colon tissue subsections also revealed significantly higher CsA concentrations in the mucosa and submucosa using SmPill® minispheres (p < 0.05).

CONCLUSIONS

Modulating E:P coating thickness controls release of CsA from SmPill® minispheres. Coated minispheres limited CsA release in the small intestine and enhanced delivery and uptake in the colon. These findings demonstrate clinical advantages of an oral coated minisphere-enabled CsA formulation in the treatment of inflammatory conditions of the large intestine.

Biologic concentration testing in inflammatory bowel disease

Anti-TNF medications have revolutionized the care of patients with inflammatory bowel disease. However, despite an initial robust effect, loss of response is common and long-term results are disappointing. Much of this lack of durability may be due to inadequate dose optimization, and recent studies suggest a correlation between serum drug concentrations and clinical outcomes. Currently, in clinical practice, measurement of drug concentrations and antibodies to drug are typically performed only when a patient presents with active inflammatory bowel disease symptoms or during a potential immune-mediated reaction to anti-TNF ("reactive" setting). However, proactive monitoring of anti-TNF concentrations with titration to a therapeutic window (i.e., therapeutic concentration monitoring) represents a new strategy with many potential clinical benefits including prevention of immunogenicity, less need for IFX rescue therapy, and greater durability of IFX treatment. This review will cover the salient features of anti-TNF pharmacokinetics and pharmacodynamics and provide a rational approach for the use of anti-TNF concentration testing in both the reactive and proactive settings.

Knowledge of Fecal Calprotectin and Infliximab Trough Levels Alters Clinical Decision-making for IBD Outpatients on Maintenance Infliximab Therapy

BACKGROUND

Infliximab is an effective therapy for inflammatory bowel disease (IBD). However, more than 50% of patients lose response. Empiric dose intensification is not effective for all patients because not all patients have objective disease activity or subtherapeutic drug level. The aim was to determine how an objective marker of disease activity or therapeutic drug monitoring affects clinical decisions regarding maintenance infliximab therapy in outpatients with IBD.

METHODS

Consecutive patients with IBD on maintenance infliximab therapy were invited to participate by providing preinfusion stool and blood samples. Fecal calprotectin (FCP) and infliximab trough levels (ITLs) were measured by enzyme linked immunosorbent assay. Three decisions were compared: (1) actual clinical decision, (2) algorithmic FCP or ITL decisions, and (3) expert panel decision based on (a) clinical data, (b) clinical data plus FCP, and (c) clinical data plus FCP plus ITL. In secondary analysis, Receiver-operating curves were used to assess the ability of FCP and ITL in predicting clinical disease activity or remission.

RESULTS

A total of 36 sets of blood and stool were available for analysis; median FCP 191.5 μg/g, median ITLs 7.3 μg/mL. The actual clinical decision differed from the hypothetical decision in 47.2% (FCP algorithm); 69.4% (ITL algorithm); 25.0% (expert panel clinical decision); 44.4% (expert panel clinical plus FCP); 58.3% (expert panel clinical plus FCP plus ITL) cases. FCP predicted clinical relapse (area under the curve [AUC] = 0.417; 95% confidence interval [CI], 0.197-0.641) and subtherapeutic ITL (AUC = 0.774; 95% CI, 0.536-1.000). ITL predicted clinical remission (AUC = 0.498; 95% CI, 0.254-0.742) and objective remission (AUC = 0.773; 95% CI, 0.622-0.924).

CONCLUSIONS

Using FCP and ITLs in addition to clinical data results in an increased number of decisions to optimize management in outpatients with IBD on stable maintenance infliximab therapy.

Immunogenicity of Anti-TNF-α Biotherapies: I. Individualized Medicine Based on Immunopharmacological Evidence

Specific inhibition of the cytokine, tumor necrosis factor-α (TNF), has revolutionized the treatment of patients with several autoimmune diseases, and genetically engineered anti-TNF antibody constructs now constitute a heavy medicinal expenditure in many countries. Unfortunately, up to 30% of patients do not respond and about 50% of those who do loose response with time. Furthermore, safety may be compromised by immunogenicity with the induction of anti-drug-antibodies (ADA). Assessment of drug pharmacokinetics and ADA is increasingly recognized as a requirement for safe and rational use of protein drugs. The use of therapeutic strategies based on anti-TNF drug levels and ADA rather than dose-escalation has also proven to be cost-effective, as this allows individualized patient-tailored strategies rather than the current universal approach to loss of response. The objective of the present article – and the accompanying article – is to discuss the reasons for recommending assessments of circulating drug and ADA levels in patients treated with anti-TNF biopharmaceuticals and to detail some of the methodological issues that obscure cost-effective and safer therapies.

Stem cell therapy in inflammatory bowel disease: A promising therapeutic strategy?

Inflammatory bowel diseases are inflammatory, chronic and progressive diseases of the intestinal tract for which no curative treatment is available. Research in other fields with stem cells of different sources and with immunoregulatory cells (regulatory T-lymphocytes and dendritic T-cells) opens up new expectations for their use in these diseases. The goal for stem cell-based therapy is to provide a permanent cure. To achieve this, it will be necessary to obtain a cellular product, original or genetically modified, that has a high migration capacity and homes into the intestine, has high survival after transplantation, regulates the immune reaction while not being visible to the patient’s immune system, and repairs the injured tissue.

Levels of drug and antidrug antibodies are associated with outcome of interventions after loss of response to infliximab or adalimumab

BACKGROUND & AIMS

There is controversy about whether levels of anti-tumor necrosis factor (TNF) and antidrug antibodies (ADAs) are accurate determinants of loss of response to therapy. We analyzed the association between trough levels of anti-TNF agents or ADAs and outcomes of interventions for patients with loss of response to infliximab or adalimumab.

METHODS

We performed a retrospective study of pediatric and adult patients with inflammatory bowel disease and suspected loss of response to anti-TNF agents treated at medical centers throughout Israel from October 2009 through February 2013. We examined the correlation between outcomes of different interventions and trough levels of drug or ADAs during loss of response. An additional subanalysis was performed including only patients with a definite inflammatory loss of response (clinical worsening associated with increased levels of C-reactive protein or fecal calprotectin, or detection of inflammation by endoscopy, fistula discharge, or imaging studies).

RESULTS

Among 247 patients (42 with ulcerative colitis), there were 330 loss-of-response events (188 to infliximab and 142 to adalimumab). Trough levels of adalimumab greater than 4.5 mcg/mL and infliximab greater than 3.8 mcg/mL identified patients who failed to respond to an increase in drug dosage or a switch to another anti-TNF agent with 90% specificity; these were set as adequate trough levels. Adequate trough levels identified patients who responded to expectant management or out-of-class interventions with more than 75% specificity. Levels of antibodies against adalimumab >4 microgram per mL equivalent (mcg/mL-eq) or antibodies against infliximab >9 mcg/mL-eq identified patients who did not respond to an increased drug dosage with 90% specificity. Patients with high titers of ADAs had longer durations of response when anti-TNF agents were switched than when dosage was increased (P = .03; log-rank test), although dosage increases were more effective for patients with no or low titers of ADAs (P = .02). An analysis of definite inflammatory loss-of-response events (n = 244) produced similar results; patients with adequate trough levels had a longer duration of response when they switched to a different class of agent than when anti-TNF was optimized by either a dosage increase or by a switch within the anti-TNF class (P = .002; log-rank test).

CONCLUSIONS

The results of this retrospective analysis suggest that trough levels of drug or ADAs may guide therapeutic decisions for more than two-thirds of inflammatory bowel disease patients with either clinically suspected or definite inflammatory loss of response to therapy.

Efficacy of sustained combination therapy for at least 6 months with thiopurines and infliximab in patients with ulcerative colitis in clinical remission: a retrospective multicenter French experience

BACKGROUND AND AIMS

Long-term benefits of combination therapy (combotherapy) with infliximab (IFX) and azathioprine (AZA) have been less studied in ulcerative colitis (UC) than in Crohn's disease. The aim of the present study was to determine UC disease activity in patients who received at least 6 months of combotherapy, and whether cotreatment for more than 6 months was useful in these patients.

METHODS

A retrospective multicenter study was conducted in seven French academic centers from January 2010 to September 2012, including all UC patients having received at least 6 months of combotherapy in prolonged remission off steroids. During the follow-up period, which was divided into trimesters, scheduled IFX was continued as maintenance and AZA could be withdrawn. Assessment of UC activity by trimester was based on the following events: disease relapse defined by clinical relapse requiring a change of treatment, IFX failure, and colectomy.

RESULTS

Eighty-two patients were included (mean age 38 years; male:female ratio 1:1) and followed up for a median of 22.3±14.0 months. Comparing 393 trimesters of combotherapy with 282 trimesters of IFX alone, fewer clinical relapses were observed with combotherapy (p = 0.049). Similar results were observed for IFX failure (p = 0.048). No difference was observed for colectomy. Duration of combotherapy longer than 9 months was inversely associated with clinical relapse (hazard ratio = 0.32 [95% confidence interval 0.15-0.70]).

CONCLUSIONS

UC patients treated with combotherapy should maintain IFX and AZA for at least 9 months. Further studies are required to determine the optimal duration of combotherapy before stopping AZA in this situation.

Human cytomegalovirus and Epstein-Barr virus infection in inflammatory bowel disease: Need for mucosal viral load measurement

AIM: To evaluate the best diagnostic technique and risk factors of the human Cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) infection in inflammatory bowel disease (IBD).

METHODS: A cohort of 40 IBD patients (17 refractory) and 40 controls underwent peripheral blood and endoscopic colonic mucosal sample harvest. Viral infection was assessed by quantitative real-time polymerase chain reaction and immunohistochemistry, and correlations with clinical and endoscopic indexes of activity, and risk factors were investigated.

RESULTS: All refractory patients carried detectable levels of HCMV and/or EBV mucosal load as compared to 13/23 (56.5%) non-refractory and 13/40 (32.5%) controls. The median DNA value was significantly higher in refractory (HCMV 286 and EBV 5.440 copies/10⁵ cells) than in non-refractory (HCMV 0 and EBV 6 copies/10⁵ cells; P < 0.05 and < 0.001) IBD patients and controls (HCMV and EBV 0 copies/10⁵ cells; P < 0.001 for both). Refractory patients showed DNA peak values ≥ 10³ copies/10⁵ cells in diseased mucosa in comparison to non-diseased mucosa (P < 0.0121 for HCMV and < 0.0004 for EBV), while non-refractory patients and controls invariably displayed levels below this threshold, thus allowing us to differentiate viral colitis from mucosal infection. Moreover, the mucosal load positively correlated with the values found in the peripheral blood, whilst no correlation with the number of positive cells at immunohistochemistry was found. Steroid use was identified as a significant risk factor for both HCMV (P = 0.018) and EBV (P = 0.002) colitis. Finally, a course of specific antiviral therapy with ganciclovir was successful in all refractory patients with HCMV colitis, whilst refractory patients with EBV colitis did not show any improvement despite steroid tapering and discontinuation of the other medications.

CONCLUSION: Viral colitis appeared to contribute to mucosal lesions in refractory IBD, and its correct diagnosis and management require quantitative real-time polymerase chain reaction assay of mucosal specimens.

Perilla frutescens extract ameliorates DSS-induced colitis by suppressing proinflammatory cytokines and inducing anti-inflammatory cytokines

Anti-inflammatory effects have been reported in Perilla frutescens leaf extract (PE), which is a plant of the genus belonging to the Lamiaceae family. We examined the effect of PE on dextran sulfate sodium (DSS)-induced colitis. Preliminarily, PE was safely administered for 7 wk without any adverse effects. In the preventive protocol, mice were fed 1.5% DSS solution dissolved in distilled water (control group) or 0.54% PE solution (PE group) ad libitum for 7 days. In the therapeutic protocol, distilled water or 0.54% PE solution was given for 10 days just after administration of 1.5% DSS for 5 days. PE intake significantly improved body weight loss. The serum cytokine profile demonstrated that TNF-α, IL-17A, and IL-10 were significantly lower in the PE group than in the control group. In the therapeutic protocol, mice in the PE group showed significantly higher body weight and lower histological colitis scores compared with mice in the control group on day 15. The serum cytokine profile demonstrated that TGF-β was significantly higher in the PE group than in the control group. In distal colon mRNA expression, TNF-α, and IL-17A were significantly downregulated. In vitro analyses of biologically active ingredients, such as luteolin, apigenin, and rosmarinic acid, in PE were performed. Luteolin suppressed production of proinflammatory cytokines, such as TNF-α, IL-1β, IL-6, and IL-17A. Apigenin also suppressed secretion of IL-17A and increased the anti-inflammatory cytokine IL-10. Rosmarinic acid increased the regulatory T cell population. We conclude that PE might be useful in treatment and prevention of DSS-induced colitis.