Antibodies to adalimumab are associated with future inflammation in Crohn's patients receiving maintenance adalimumab therapy: a post hoc analysis of the Karmiris trial

Update on Therapeutic Drug Monitoring in Crohn's Disease

In patients with Crohn's disease on biologic medications, the use of therapeutic drug monitoring leads to a personalized approach to optimize treatment. Using an algorithmic approach, measurement of drug concentrations and anti-drug antibodies can be used to improve treatment outcomes. Therapeutic drug concentrations and absence of antibodies are associated with improved clinical and endoscopic outcomes. In clinical practice, therapeutic drug monitoring has been shown to be clinically useful and cost-effective in patients experiencing a loss of response to treatment. This review highlights the available data on therapeutic drug monitoring in the treatment of patients with Crohn's disease on biologic medications.

Immunogenicity of Biologics in Chronic Inflammatory Diseases: A Systematic Review

OBJECTIVES

A systematic review was conducted to explore the immunogenicity of biologic agents across inflammatory diseases and its potential impact on efficacy/safety.

METHODS

Literature searches were conducted through November 2016 to identify controlled and observational studies of biologics/biosimilars administered for treatment of rheumatoid arthritis (RA), psoriatic arthritis (PsA), juvenile idiopathic arthritis (JIA), ankylosing spondylitis (AS), non-radiographic axial spondyloarthritis (nr-axSpA), psoriasis (Ps), Crohn's disease, and ulcerative colitis.

RESULTS

Of >21,000 screened publications, 443 were included. Anti-drug antibody (ADAb) rates varied widely among biologics across diseases (and are not directly comparable because of immunoassay heterogeneity); the highest overall rates were reported with infliximab (0-83%), adalimumab (0-54%), and infliximab biosimilar CT-P13 (21-52%), and the lowest with secukinumab (0-1%), ustekinumab (1-11%), etanercept (0-13%), and golimumab (0-19%). Most ADAbs were neutralizing, except those to abatacept and etanercept. ADAb+ versus ADAb- patients had lower rates of clinical response to adalimumab (RA, PsA, JIA, AS, Ps), golimumab (RA), infliximab (RA, PsA, AS, Ps), rituximab (RA), ustekinumab (Ps), and CT-P13 (RA, AS). Higher rates of infusion-related reactions were reported in infliximab- and CT-P13-treated ADAb+ patients. Background immunosuppressives/anti-proliferatives reduced biologic immunogenicity across diseases.

CONCLUSIONS

Based on reviewed reports, biologic/biosimilar immunogenicity differs among agents, with the highest rates observed with infliximab and adalimumab. As ADAb formation in biologic-/biosimilar-treated patients may increase the risk of lost response, the immunogenicity of these agents is an important (albeit not the only) consideration in the treatment decision-making process.

Serum Adalimumab Levels Predict Successful Remission and Safe Deintensification in Inflammatory Bowel Disease Patients in Clinical Practice

BACKGROUND

Little is known about the association between the pharmacokinetic features of adalimumab (ADL) and disease outcome in patients with inflammatory bowel disease (IBD).

AIMS

To assess the association between random serum ADL levels and clinical or biochemical remission with clinical decision making in daily practice according to these levels; and to determine the cutoff value for successful dose reduction in patients with IBD treated with ADL.

METHODS

We conducted a prospective observational study of patients with IBD who received long-term maintenance therapy with ADL.

RESULTS

Data were available for 157 serum samples from 87 patients. Serum ADL levels were associated with clinical remission: median 9.2 versus 6.0 μg/mL for patients with Crohn's disease with active disease (P = 0.009) and 14.4 versus 5.2 μg/mL in patients with ulcerative colitis with active disease (P = 0.002). Serum ADL levels were 9.2 μg/mL for patients with a normal C-reactive protein value (<5 mg/L) and 5.2 μg/mL for patients with a high C-reactive protein value (P = 0.002). ADL levels were significantly associated with normal fecal calprotectin value (<80 ng/g) (10.8 versus 7.6 μg/mL, respectively, P = 0.038). Serum ADL levels were significantly associated with successful deintensification, over a 6-month period of clinical follow-up, compared with the group in which doses remained unchanged (area under the curve 0.88; 95% confidence interval, 0.81-0.95; P < 0.001), with a cutoff value for successful deintensification of 12.2 μg/mL.

CONCLUSIONS

Higher ADA levels were significantly associated with clinical and biochemical remission. Our results, which were obtained under conditions of daily clinical practice, suggest that an ADL cutoff of 12.2 μg/mL could be appropriate for successful dose reduction in patients with IBD treated with ADL.

Utilisation of anti-TNF levels in a UK tertiary IBD centre

OBJECTIVE

To ascertain how anti-tumour necrosis factor (TNF) drug and anti-drug antibody levels testing is used in a 'real-world' setting to optimise inflammatory bowel disease (IBD) treatment.

DESIGN

Retrospective cohort study of prospectively collected patient data.

SETTING

Tertiary IBD centre in London, UK.

PATIENTS

All patients at Guy's and St Thomas' Hospitals on anti-TNF who had levels measured between the start of testing in 2012 and October 2014.

INTERVENTIONS

Anti-TNF drug and anti-drug antibody levels as part of routine monitoring.

MAIN OUTCOME MEASURES

Indication for measuring levels and changes in management made as a result of the levels.

RESULTS

330 infliximab levels were carried out in 199 patients and 143 adalimumab levels were carried out in 103 patients. Levels were primarily done in those with evidence of loss of response; 37% of infliximab levels and 52% of adalimumab levels. Levels resulted in a change in management in 26% of patients in infliximab group and 25% of patients in adalimumab group; however, this was greater in those with loss of response, 62% and 61% respectively. Anti-drug antibodies were detected in 7% of patients.

CONCLUSIONS

Our early experience has demonstrated that measuring anti-TNF drug and anti-drug antibody levels can be useful in the optimisation of IBD management. In an increasing number of patients, particularly those with evidence of loss of response, it allows early decisions to be made regarding changing therapy. It also offers the potential for significant cost-saving by preventing pointless dose escalation in the context of therapeutic levels or when high-level anti-drug antibodies are present.

Incidence, Prevention and Management of Anti-Drug Antibodies Against Therapeutic Antibodies in Inflammatory Bowel Disease: A Practical Overview

The introduction of biologic therapy has revolutionized the treatment of inflammatory bowel disease (IBD). However, like all therapeutic proteins, monoclonal antibodies have immunogenic potential which is influenced by multiple drug- and patient-related factors. The reported incidence of anti-drug antibodies (ADAs) towards biologic drugs in IBD varies greatly in the literature and depends not only on differences in sensitization but also on the assay methodology and the timepoint of measurement. Sensitization with formation of ADAs is associated with an increased risk of infusion reactions, accelerated drug clearance, and a loss of response (LOR) to drug. Recently, a greater understanding of the pharmacokinetics of therapeutic antibodies has led to the development of new strategies to reduce immunogenicity and more efficient use of these drugs. These preventive strategies include regular scheduled dosing with maintenance of stable therapeutic trough drug concentrations, and co-administration of an immunosuppressive. Sub-therapeutic drug concentrations with low levels of ADAs can generally be overcome with dose escalation, whereas the presence of high concentrations of ADAs requires a switch to another therapeutic agent.

Detection of adalimumab and antibodies to adalimumab using a homogeneous mobility shift assay

OBJECTIVE

In 2013 a novel commercial test was launched (Anser ¹ ADA test) for the assay of serum adalimumab (ADL) and antibodies to adalimumab (ATA). This study aims to understand clinical practice patterns used with ADL in a real-world cross-sectional population.

METHODS

Wilcoxon rank sum test, and linear and logistic regression methods were applied in the statistical analysis to test hypotheses. The study design was observational and uncontrolled.

RESULTS

Of a total of 14,239 tests conducted, 5509 had information available that pertained to reasons for ordering, of which disease monitoring (46.9%) was the most common. Median serum ADL level with standard maintenance dosing (40 mg, biweekly) was 8.8 μg/mL (n = 2901). A five-fold decrease in median serum ADL levels occurred with very low ATA titers (1.7-3 U/mL, p < .0001). Serum ADL levels decreased further with ATA >7 U/mL (p < .0001). A total of 16.5% of patients were ATA positive, of whom 61.9% had low ATA (1.7-7 U/mL); 87.9% of ATA-positive patients had serum ADL levels ≤4.4 μg/mL. Expression of inflammatory markers significantly increased with high ATA (>7 U/mL). An inverse relationship between ADL and ATA was observed (R²: 0.49), and 4.1 μg/mL was identified as a cut-off that may segregate ATA-positive patients.

CONCLUSION

In this real-world cross-sectional population, serum ADL levels decreased with increasing ATA titers, with low ATA titers (≤7 U/mL) significantly reducing serum ADL compared to ATA-negative samples. Expression of inflammatory markers significantly increased at higher ATA titers (>7 U/mL). These findings highlight the clinical importance of monitoring patients for drug levels and anti-drug antibody titers.

The Impact of Therapeutic Antibodies on the Management of Digestive Diseases: History, Current Practice, and Future Directions

The development of therapeutic antibodies represents a revolutionary change in medical therapy for digestive diseases. Beginning with the initial studies that confirmed the pathogenicity of cytokines in inflammatory bowel disease, the development and application of therapeutic antibodies brought challenges and insights into their potential and optimal use. Infliximab was the first biological drug approved for use in Crohn's disease and ulcerative colitis. The lessons learned from infliximab include the importance of immunogenicity and the influence of pharmacokinetics on disease response and outcomes. Building on this foundation, other therapeutic antibodies achieved approval for inflammatory bowel disease and many more are in development for several digestive diseases. In this review, we reflect on the history of therapeutic antibodies and discuss current practice and future directions for the field.

Review article: dose optimisation of infliximab for acute severe ulcerative colitis

BACKGROUND

Although optimal medical management of acute severe ulcerative colitis (UC) is ill-defined, infliximab has become a standard of care. Accumulating evidence suggests an increased rate of infliximab clearance in patients with acute severe UC and a reduced colectomy rate with an intensified infliximab induction regimen.

AIM

To assess the strength of the current evidence for the relationship between infliximab pharmacokinetics, dosing strategies and disease behaviour in patients with acute severe UC.

METHODS

We systematically searched MEDLINE and conference proceedings from 2000 to 2016 for relevant articles describing the pharmacokinetics of infliximab in acute severe UC and/or infliximab dose intensification strategies in acute severe UC. Eligible articles described randomised controlled trials, and cohort, cross-sectional, and case-controlled studies.

RESULTS

Of 400 citations identified, 76 studies were eligible. Increased infliximab clearance occurs in patients with acute severe UC, and is driven by the total inflammatory burden and leakage of drug into the colonic lumen. Several cohort studies suggest that infliximab dose intensification is beneficial to at least 50% of acute severe UC patients and the results of case-controlled studies indicate that an intensified infliximab dosing regimen with 1-2 additional infusions in the first 3 weeks of treatment could reduce the early (3-month) colectomy rate by up to 80%, although these data require prospective validation.

CONCLUSIONS

Uncontrolled studies suggest a benefit for infliximab dose optimisation in patients with acute severe UC. A randomised controlled trial in acute severe UC patients comparing a personalised infliximab dose-optimisation strategy with conventional dosing is a research priority.

Clinical impact of immunomonitoring in the treatment of inflammatory bowel disease

Despite improvement in outcomes, loss of response (LOR) to tumor necrosis factor-alpha (TNFα) therapies is a big concern in the management of inflammatory bowel disease. LOR is associated with flares of disease, increased hospitalisation rates, need for surgical interventions, and decline in quality of life. LOR may be multifactorial, but immunogenicity makes a significant contribution. Traditionally doses of anti-TNFα have been adjusted based on clinical response, using a standard approach. Immunomonitoring involves the measurement of anti-TNFα trough and antibody levels. It takes into account the underlying pharmacokinetics of anti-TNFα therapies. Expanding on this a treat to target approach may be used, where doses are intensified, or tailored to the individual based on the measurement of anti-TNFα trough and antibody levels. This review looks at the history, evolution, and clinical impact that immunomonitoring is having in the treatment of inflammatory bowel disease. It will focus on the role of immunomonitoring in helping to achieve long lasting deep remission and mucosal healing. It will explore the different options in terms of best measuring trough and antibody levels, explore possible advantages of immunomonitoring, and discuss its role in best optimising response, at induction, during the maintenance phase of treatment, as well as a role in withdrawing or switching therapy.

Development and Internal Validation of a Model Using Fecal Calprotectin in Combination with Infliximab Trough Levels to Predict Clinical Relapse in Crohn's Disease

BACKGROUND

The best noninvasive method predicting clinical relapse remains undetermined in infliximab (IFX)-treated patients with Crohn's disease.

METHODS

All patients with CD on IFX maintenance treatment and in clinical remission for at least 16 weeks, between 2011 and 2014, were enrolled in a prospective single-center study. The Crohn's Disease Activity Index (CDAI), fecal calprotectin, C-reactive protein levels, antibodies (ATI), and trough level (TLI) of IFX were measured at every IFX infusion. The best thresholds of TLI (2 versus 3 μg/mL) and calprotectin (50 versus 250 μg/g stools) were identified across four logistic regression models.

RESULTS

One hundred nineteen patients (mean age: 34 ± 12 yrs, mean disease duration: 7.8 yrs) were included. Mean follow-up was 20.4 months, and 17% of the patients were on IFX and azathioprine at inclusion. During follow-up, 37 patients (31.1%) relapsed, 78% within the first 6 months. The clinical characteristics of the relapsed and nonrelapsed patients were similar. After logistic regression, fecal calprotectin >250 μg/g stools (OR: 4.09; 95% CI, 1.01-16.21; P = 0.049) and TLI <2 μg/mL (OR: 14.85; 95% CI, 3.67-60; P < 0.0001) were associated with loss of response. A training cohort of 55 patients was isolated randomly to implement prediction rules for loss of response. The best predictive rules were the combination of a TLI <2 μg/mL and a fecal calprotectin level >250 μg/g stools (78.3%). These rules were validated on a test cohort of 64 patients with an accuracy of 87%, (sensitivity = 0.94, specificity = 0.84, positive predictive value = 0.73, and negative predictive value = 0.97).

CONCLUSIONS

In IFX-treated patients with CD in clinical remission, a combination of TLI (<2 μg/mL) and fecal calprotectin (>250 μg/g of stools) is a good model for predicting loss of response. In contrast with previous data, low TLIs ranging from 2 to 3 μg/mL should neither systematically lead to the optimization of IFX use nor a switch in the treatment.

Addition of an immunomodulator can reverse antibody formation and loss of response in patients treated with adalimumab

BACKGROUND

Anti-adalimumab antibodies (AAA) are associated with loss of clinical response (LOR). Addition of an immunomodulator has been shown to reverse immunogenicity and regain response with infliximab monotherapy. Similar data on adalimumab are lacking.

AIM

To study the impact of immunomodulator addition on the emergence of AAA and LOR among adalimumab therapy patients.

METHODS

The databases of three tertiary medical centres were reviewed to identify patients who developed AAA during adalimumab monotherapy with resultant LOR, and received an immunomodulator as a salvage combination therapy. All sera were prospectively analysed using previously described ELISA assays. Clinical response was determined using appropriate clinical scores. Elimination of AAA, designated as 'sero-reversal', elevation of drug levels and regained clinical response were the sought outcomes.

RESULTS

Twenty-three patients (21 Crohn's disease, and 2 ulcerative colitis) developed AAA with subsequent LOR and were thereafter prescribed an immunomodulator as salvage therapy (thiopurine n = 14, methotrexate n = 9). Eleven patients (48%) underwent sero-reversal with gradual elimination of AAA, increase in drug trough levels and restoration of clinical response (median time to sero-reversal 5 months). In 12 patients (52%), immunogenicity and loss of response could not be reversed. There was no difference between responders and nonresponders in the type of immunomodulators used or baseline clinical characteristics.

CONCLUSIONS

In almost half of inflammatory bowel disease patients developing anti-adalimumab antibodies and loss of response, established immunogenicity of adalimumab can be gradually reversed by the addition of immunomodulator therapy with restoration of a clinico-biological response. However, these observations need to be confirmed with larger studies.

Post-Induction Adalimumab Concentration is Associated with Short-Term Mucosal Healing in Patients with Ulcerative Colitis

BACKGROUND AND AIMS

Mucosal healing is associated with favourable therapeutic outcomes in patients with ulcerative colitis [UC]. We investigated whether adalimumab concentrations during induction therapy are associated with short-term mucosal healing [STMH] in UC patients.

METHODS

This was a retrospective, single-centre study including consecutive UC patients treated with adalimumab from June 2005 to May 2014, who underwent an endoscopy both at baseline and after induction therapy [weeks 8-14] and at least one serum sample available at week 2 and/or week 4. STMH was defined as Mayo endoscopic sub-score of ≤1 with a baseline sub-score of ≥2. Adalimumab concentrations were evaluated using an in-house developed enzyme-linked immunosorbent assay.

RESULTS

The study population consisted of 43 patients, the majority of whom [n = 38] were prior infliximab failures; the rest showed primary non-response [PNR, n = 5]. Twelve patients [27.9%] achieved STMH. Patients with STMH had higher adalimumab concentrations at week 4 compared to those without [10.6 vs 7.4 μg/ml, p = 0.014]. A receiver operating characteristic [ROC] analysis identified an adalimumab concentration threshold at week 4 of 9.4 μg/ml (area under the ROC curve [AUROC]: 0.778) and 7.5 μg/ml [AUROC: 0.798], after excluding patients with PNR to infliximab, to be associated with STMH. Multiple logistic regression analysis, after excluding patients with PNR to infliximab, identified adalimumab concentration ≥7.5 μg/ml at week 4 (odds ratio [OR]: 15.7; 95% confidence interval [CI]: 1.3-185; p = 0.029) and baseline endoscopic Mayo score 3 [OR: 0.13; 95% CI: 0.02-0.98; p = 0.047] as factors independently associated with STMH.

CONCLUSIONS

This study, reflecting real-life clinical practice, demonstrated that post-induction adalimumab concentrations are associated with STMH, while higher baseline mucosal inflammation is related to lack of STMH in UC.

Controversies in Establishing Biosimilarity: Extrapolation of Indications and Global Labeling Practices

The principles of establishing biosimilarity are to demonstrate structural and functional similarity to a reference product using the most discriminatory analytical methods. There is still considerable controversy on the scientific basis for extrapolation of indications for biosimilars, which has been strengthened by diverging global regulatory decision making. Closely related to the question of extrapolation is the question of how to communicate the evidence base for authorizing biosimilars to healthcare professionals. In this paper we will consider some of the discussions around extrapolation of indications and the implications of decisions of various regulatory agencies in the world regarding the authorization and labeling of biosimilars.

Therapeutic Drug Monitoring and Clinical Outcomes in Immune Mediated Diseases: The Missing Link

As the incidence of inflammatory bowel diseases and the number of patients treated with anti-TNF agents keep on increasing so are the phenomena of primary non response (PNR) and secondary loss of response (SLR) to these medications. Traditionally PNR and SLR have been managed empirically-that is, switching medications for PNR and increasing the anti-TNF dose for SNR. More recently an approach based on testing drug levels and antibodies to the drug (therapeutic drug monitoring) has gained increasing popularity in the management of inflammatory bowel diseases. However, while this strategy might offer an insight into the mechanisms leading to PNR/SLR it often falls short of providing a simple, reproducible method to manage these issues in clinical practice. Here, we will review the currently recommended therapeutic strategies when using therapeutic drug monitoring; the evidence for and against such approach and the current standard strategies in Rheumatology (the specialty with the largest and longest experience with anti-TNF agents). We will then discuss the possible reasons of the shortcomings of therapeutic drug monitoring and the rationale and need to move the therapeutic target to the disease burden in inflammatory bowel diseases-along with the supporting preliminary evidence. Finally, we will focus on future crucial studies that need to be done to make approaches to PNR/SLR more rigorous and at the same time user-friendly for the practicing gastroenterologist.

Use of anti-TNF drug levels to optimise patient management

Anti-tumour necrosis factor (TNF) therapies, such as infliximab, adalimumab, certolizumab pegol and golimumab, have been proven to be effective for the treatment of patients with Crohn's disease and ulcerative colitis. However, 10%-30% of patients with inflammatory bowel disease (IBD) show no initial clinical benefit to anti-TNF therapy (primary non-response), and over 50% after an initial favourable outcome will lose response over time (secondary loss of response (SLR)). Numerous recent studies in IBD have revealed an exposure-response relationship suggesting a positive correlation between high serum anti-TNF concentrations and favourable therapeutic outcomes including clinical, biomarker and endoscopic remission, whereas antidrug antibodies have been associated with SLR and infusion reactions. Currently, therapeutic drug monitoring (TDM) is typically performed when treatment failure occurs either for SLR, drug intolerance (potential immune-mediated reaction) or infusion reaction (reactive TDM). Nevertheless, recent data demonstrate that proactive TDM and a treat-to-target (trough) therapeutic approach may more effectively optimise anti-TNF therapy efficacy, safety and cost. However, implementing TDM in real-life clinical practice is currently limited by the diversity in study design, therapeutic outcomes and assays used, which have hindered the identification of robust clinically relevant concentration thresholds. This review will focus mainly on the pharmacodynamic properties of anti-TNF therapy and the role of TDM in guiding therapeutic decisions in IBD.

Appropriateness of Testing for Anti-Tumor Necrosis Factor Agent and Antibody Concentrations, and Interpretation of Results

BACKGROUND & AIMS

The availability of tests for blood concentrations of anti-tumor necrosis factor (TNF) agents and antibodies against these drugs could improve dose selection for patients with inflammatory bowel disease (IBD). However, there is little consensus on when to test and how to interpret test results. We used the RAND/UCLA Appropriateness Method to determine when these tests are appropriate and how to clinically interpret their results.

METHODS

We conducted a systematic literature search in November 2013 to identify observational or experimental studies of the measurement of anti-TNF drug and antibody concentrations in patients with IBD and interpretation of their results. We developed 35 scenarios that assessed the appropriateness of testing and 143 scenarios that addressed clinical strategies in response to test results, and presented the findings to an expert panel. The appropriateness of each scenario was rated before and after an in-person meeting with the panel. Panelists rated the appropriateness of various clinical management options including changing therapy within class, switching out of class, adjusting drug dose or interval, adding or adjusting concomitant immune modulators, and doing nothing for each of 6 permutations of high versus low drug concentrations and high, low, or undetectable antibody concentrations. Disagreement was assessed using a validated index.

RESULTS

Assessment of anti-TNF drug and antibody concentrations was rated appropriate at the end of induction therapy in primary nonresponders, in secondary nonresponders, at least once during the first year of maintenance therapy, and following a drug holiday. Routine assessment in responders at the end of induction was rated uncertain. In nearly all scenarios, escalation of drug dosing was rated appropriate when drug concentration was low in the absence of antibodies, and switching within class was rated appropriate when antibodies were present. Other recommendations depended on the specific clinical scenario for which the test was obtained.

CONCLUSIONS

Based on the RAND/UCLA Appropriateness Method of analysis, an expert panel recommends testing for drug and antibody concentrations in many clinical scenarios. The appropriate timing and best way to respond to anti-TNF drug and antibody testing for IBD depends on the specific clinical scenario. These recommendations can help guide clinicians to best optimize anti-TNF therapy.

Clinical efficacy of adalimumab in Crohn's disease: a real practice observational study in Japan

Background

There are few reports of the efficacy of adalimumab (ADA) for clinical remission and preventing postoperative recurrence in Crohn's disease (CD) in Asian real practice settings. We conducted a Japanese multicenter retrospective observational study.

Methods

We evaluated patients with CD who were treated with ADA at 11 medical institutions in Japan to investigate the clinical efficacy of remission up to 52 weeks and the associated factors to achieve remission with a CD Activity Index (CDAI) < 150. The effects of preventing postoperative recurrence were also evaluated.

Results

In 62 patients, the remission rates were 33.9, 74.2, 75.8, 77.4, and 66.1 % at 0, 4, 12, 26, and 52 weeks, respectively. Although 10 patients discontinued treatment due to primary nonresponse, secondary nonresponse, or adverse events, the ongoing treatment rate at 52 weeks was 83.9 %. Comparison of remission and non-remission on univariate analysis identified colonic type and baseline CDAI value as significant associated factors (P < 0.05). In 16 patients who received ADA to prevent postoperative recurrence, the clinical remission maintenance rate was 93.8 % and the mucosal healing rate was 64.3 % during a mean postoperative follow-up period of 32.3 months.

Conclusions

ADA effectively induced remission and prevented postoperative recurrence in patients with CD in a real practice setting.

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.

Adalimumab and pharmacokinetics: Impact on the clinical prescription for inflammatory bowel disease

Anti-tumor necrosis factor (TNF) drugs are widely prescribed for inflammatory disease. A loss of response to adalimumab is frequent and the pharmacokinetics of anti-TNF therapy have important implications for patient management. Individual factors such as albumin, body weight, and disease severity based on the C-reactive protein level influence drug metabolism. Adalimumab trough levels are associated with clinical remission. On the other hand, the detection of antibodies is associated with clinical relapse. Immunosuppressive therapy could reduce antibody formation although the clinical impact is not proven. New algorithms are available to provide personalized treatment and adapt the dosage. More data are needed on dose de-escalation.

Systematic review: predicting and optimising response to anti-TNF therapy in Crohn's disease - algorithm for practical management

BACKGROUND

Nonresponse and loss of response to anti-TNF therapies in Crohn's disease represent significant clinical problems for which clear management guidelines are lacking.

AIM

To review the incidence, mechanisms and predictors of primary nonresponse and secondary loss of response to formulate practical clinical algorithms to guide management.

METHODS

Through a systematic literature review, 503 articles were identified which fit the inclusion criteria.

RESULTS

Primary nonresponse to anti-TNF treatment affects 13-40% of patients. Secondary loss of response to anti-TNF occurs in 23-46% of patients when determined according to dose intensification, and 5-13% of patients when gauged by drug discontinuation rates. Recent evidence suggests that the mechanisms underlying primary nonresponse and secondary loss of response are multifactorial and include disease characteristics (phenotype, location, severity); drug (pharmacokinetic, pharmacodynamic or immunogenicity) and treatment strategy (dosing regimen) related factors. Clinical algorithms that employ therapeutic drug monitoring (using anti-TNF tough levels and anti-drug antibody levels) may be used to determine the underlying cause of primary nonresponse and secondary loss of response respectively and guide clinicians as to which patients are most likely to respond to anti-TNF therapy and help optimise drug therapy for those who are losing response to anti-TNF therapy.

CONCLUSIONS

Nonresponse or loss of response to anti-TNF occurs commonly in Crohn's disease. Clinical algorithms utilising therapeutic drug monitoring may establish the mechanisms for treatment failure and help guide the subsequent therapeutic approach.

Ustekinumab for the treatment of Crohn's disease: can it find its niche?

Crohn's disease is an immune-mediated disease that results in panenteric chronic inflammation in genetically predisposed individuals exposed to an appropriate environment. The past two decades have witnessed the emergence of an important class of drugs known as anti-tumour necrosis factor (TNF) agents in the treatment of Crohn's disease. Unfortunately, the utility of these agents have been hampered by primary and secondary nonresponse in a significant proportion of patients. Ustekinumab, a monoclonal antibody to the p40 subunit of interleukin (IL) 12 and 23, is a novel pharmacotherapy for this patient cohort that offers an out-of-class option. It is approved for use in psoriasis and psoriatic arthritis, and has now been evaluated in phase II trials for moderate-to-severe Crohn's disease. We here review the published literature and describe a potential clinical role for its use in this disease cohort.

Optimizing biologic treatment in IBD: objective measures, but when, how and how often?

Background

The advent of biologic agents for the treatment of inflammatory bowel disease (IBD) was accompanied in parallel with emerging understanding of persisting underlying inflammation and ensuing bowel damage that can occur even in patients with seeming clinical remission. This lead to the concepts of mucosal healing and deep remission gaining acceptance as the more desired goals for therapy within an ambitious disease-control therapeutic approach, namely, treat-to-target strategy. However, how to practically monitor IBD patients, which objective measures to follow, at what time-points and whether to act upon results in asymptomatic patients are all questions that remain disputed.

Methods and result

In this concise review we aim to provide an overview of objective measures for monitoring of IBD patients, focusing on the challenging group of patients treated by infliximab, adalimumab, vedolizumab and other biologics. These objective measures are discussed in the context of the different common clinical scenarios wherein the clinician may contemplate their use. Specifically, we will delineate the role of objective parameters to be monitored during induction phase of treatment, during maintenance therapy, at loss of response and after elective cessation of therapy in patients in remission.

Conclusion

Coupled with the non-negligible costs of therapy, and the over-all worse prognosis of moderate-severe patients who are the usual recipients of biologic therapies, this challenging patients seem to be the first candidates for this more proactive strategy combining inflammatory and pharmacokinetic monitoring of objective inflammatory and pharmacokinetic measures. More data is still desirable to better define the exact parameters to be followed and their optimal thresholds, and to delineate the optimal cost-effective interventions for these patients.