Effectiveness of concomitant immunosuppressive therapy in suppressing the formation of antibodies to infliximab in Crohn's disease

Proactively Optimized Infliximab Monotherapy Is as Effective as Combination Therapy in IBD

BACKGROUND

Infliximab (IFX) discontinuation is not uncommon during the first year of treatment due to inadequate drug concentrations and anti-IFX antibodies (ATI). Both combination therapy and proactive therapeutic drug monitoring (pTDM) are used to decrease ATI and increase IFX durability. We proposed that monotherapy (Mono) is as effective as combination therapy (Combo) if the first maintenance infusion is dosed based on week 10 pTDM.

METHODS

In a retrospective cohort of 83 patients with inflammatory bowel disease (IBD), we examined the frequency of IFX discontinuation, ATI, infusion reactions, and IFX concentrations during the first year of treatment in patients receiving week 10 pTDM-guided IFX monotherapy (Mono pTDM; n = 16) compared with patients on mono (n = 32) or combination therapy (n = 35) in whom TDM was introduced at or after week 14, per standard of care (SOC).

RESULTS

The frequency of IFX discontinuation was lower with Mono pTDM compared with Mono SOC (P = 0.04) but did not differ with Combo SOC (P = 1). At first TDM, no patient in the pTDM strategy had ATI, vs 41% in Mono SOC (P = 0.002) and 6% in Combo SOC (P = 1). Of the 13 subjects with ATI in Mono SOC, 7 (47%) had ATI already at week 14. IFX trough concentrations with Mono pTDM were higher during maintenance compared with Mono SOC (9.5 vs 6.4 µg/mL, P = 0.04) but not Combo SOC.

CONCLUSIONS

Infliximab durability did not differ between patients on IFX monotherapy dosed based on p-TDM and patients receiving combination therapy. In the absence of concomitant immunosuppression, proactive TDM may improve IFX durability by maintaining higher IFX concentrations entering into maintenance. Further studies are needed to confirm our findings.

Nomenclature of humanized mAbs: Early concepts, current challenges and future perspectives

Nomenclature of monoclonal antibodies traditionally followed a strict scheme indicating target and species information. Because of the rapid advances in this field, emphasized by approval of four humanized and six human antibodies in 2017, the International Nonproprietary Name of new antibodies was updated profoundly by removing the species substem completely. In this review we give an overview about what developments led to the preference of the scientific community towards human-like antibodies. We summarize the major updates in naming schemes that tried to classify antibodies according to their humanization technique or to the final primary sequence and how this led to the erroneous perception to indicate expected immunogenicity. Following the new 2017 nomenclature update, there will not be any information available about the species origin in the names of new antibodies, which emphasizes the need for providing additional supplemental information to the scientific community and develop tools to accurately estimate and control the safety of new monoclonal antibody molecules.

Recapture and improved outcome of pegloticase response with methotrexate-A report of two cases and review of the literature

INTRODUCTION

Pegloticase is a PEGylated uric acid specific enzyme indicated for the treatment of refractory gout. Anti-pegloticase antibodies contribute to high discontinuation rates, increased risk of infusion reactions, and early loss of drug efficacy.

OBJECTIVE

To describe the use of methotrexate to recapture function of pegloticase after development of anti-drug antibodies while treating gout.

METHODS

We report two cases of using methotrexate as an adjunct to treatment with pegloticase for refractory tophaceous gout. We also present the results of a literature review on the use of concomitant immunosuppressive therapy with pegloticase to prevent anti-pegloticase antibody development.

RESULTS

Patient A, a 55-year-old man with a history of tophaceous gout, was treated with pegloticase but developed high serum urate(sUA) levels prior to his third infusion. Adjunctive treatment with methotrexate restored pegloticase response and the patient's sUA levels decreased, and remained low for the remainder of his treatment. Patient B, a 36-year-old man with a history of tophaceous gout, was treated with pegloticase. Oral methotrexate was initiated at the first infusion. Low sUA levels were achieved but increased after a lapse in methotrexate compliance. Re-initiation of methotrexate restored pegloticase response and the patient tolerated subsequent infusions. Literature review identified three reports of successful use of concomitant pegloticase and immunosuppressive therapy for refractory tophaceous gout, including an open label trial with a subset of 7 transplant recipients, an additional case study of pegloticase treatment with one transplant recipient, and a case study of pegloticase administered with low-dose azathioprine.

CONCLUSION

Prophylactic use of immunosuppressive therapy with pegloticase may enable sustained treatment and improve outcomes. Additionally, immunosuppressive therapy seems to show the ability to recapture pegloticase response after development of anti-drug antibodies. The use of immunosuppressants to prevent anti-drug antibody formation, recapture pegloticase efficacy, and reduce discontinuation rates warrants further study.

Adalimumab persistence for inflammatory bowel disease in veteran and insured cohorts

OBJECTIVES

Identify predictors of persistence with adalimumab (ADA) among veterans and privately insured patients with inflammatory bowel disease (IBD) in the United States.

STUDY DESIGN

Retrospective cohort study.

METHODS

Patients with IBD taking ADA as their first biologic were identified from the Veterans Health Administration (VHA) database from 2009 to 2013 and the Truven Health MarketScan database from 2009 to 2012 with a 12-month follow-up. Persistence was defined as continued use 1 year after initiation. Adherence was assessed by calculating a medication possession ratio, which was dichotomized as greater than 0.86 or less than or equal to 0.86. Multivariable logistic regression was used to evaluate predictors of persistence.

RESULTS

There were 1030 patients in the VHA population compared with 3264 patients in the privately insured (MarketScan) cohort. In MarketScan, 1800 patients (55%) remained on ADA compared with 755 (73%) in the VHA cohort. In multivariable analysis, male sex (odds ratio [OR], 1.38; 95% CI, 1.16-1.63; P <.01), Crohn disease (OR, 1.27; 95% CI, 1.02-1.57; P = .03), greater adherence (OR, 1.83; 95% CI, 1.45-2.30; P <.01), and dose escalation (OR, 1.82; 95% CI, 1.42-2.33; P <.01) were associated with higher ADA persistence in the MarketScan cohort; narcotic use (OR, 0.71; 95% CI, 0.58-0.88; P <.01) and hospitalization or new steroid use after initiation (OR, 0.04; 95% CI, 0.03-0.05; P <.01) were associated with lower persistence. In the VHA cohort, only a hospitalization or new steroid use (OR, 0.50; 95% CI, 0.36-0.70; P <.01) was associated with lower persistence.

CONCLUSIONS

Despite being older and having more comorbidities, patients in the VHA, which is an integrated healthcare system, appear to be more likely to remain on ADA at 1 year than patients in the MarketScan database. Further studies of system differences are needed to understand the reasons behind this discrepancy.

Pharmacokinetics and Immune Reconstitution Following Discontinuation of Thiopurine Analogues: Implications for Drug Withdrawal Strategies

BACKGROUND AND AIMS

Discontinuation of thiopurine analogues is common prior to live vaccines, during infection or when de-escalating therapy. Data regarding clearance of active metabolites and immune re-constitution is scant. We aimed to determine drug elimination and immune re-constitution following thiopurine cessation.

METHODS

The elimination kinetics of 6-thioguanine nucleotides (6-TGN) were determined in nine inflammatory bowel disease [IBD] patients discontinuing thiopurines. Immune reconstitution was evaluated by toxic shock syndrome toxin 1 [TSST1] or anti-CD3 [OKT3]-induced CD4+ T-cell proliferation, following an initial exposure to TSST1 and 6-mercaptopurine [6MP], separately or combined.

RESULTS

All patients discontinuing thiopurines displayed first-order elimination kinetics of 6-TGN, with a median elimination half-life of 6.8 days [interquartile range 5.9-8.4]. Resting CD4+ T-cells exposed to 6MP preserved their response to subsequent polyclonal or Vβ2+-preferential stimulation. By contrast, exposure of TSST1-activated CD4+ T-cells to 6MP inhibited their subsequent Vβ2+clonal response to further stimulation [p = 0.008], whereas overall response to further non-Vβ2-selective stimulation with OKT3 was unaltered [p = 0.9].

CONCLUSIONS

Upon 6MP/azathioprine discontinuation, a 6-TGN elimination half-life of less than 10 days is expected in most patients. Immune reconstitution, however, may take longer for T-cell clones exposed to stimulation during thiopurine treatment. These findings may be useful when considering thiopurine cessation.

Evaluation of Rapid vs Standard Infliximab Infusions in the Pediatric Population

BACKGROUND

Rapid 1-hour infliximab infusions have been safely implemented in adults, but studies of these rapid infusions in pediatric patients are limited. This study's primary objective was to determine the safety of 1-hour infliximab infusions compared with standard 2- to 3-hour infusions in children with inflammatory bowel disease and other autoimmune disorders.

METHODS

We conducted an institutional review board-approved prospective study using an unmatched historical control group at a freestanding children's hospital comparing rapid vs standard infusion rates of infliximab and the use of premedications and immunomodulatory agents on the frequency of early and delayed infusion reactions.

RESULTS

There were 50 subjects with 540 total standard (2- to 3-hour) infusions in the retrospective group and 66 subjects with 545 total rapid (1-hour) infusions assessed in the prospective group. Although the prospective group received a significantly higher infliximab dose, was significantly less likely to receive premedication, and was significantly more likely to receive another immunomodulatory agent, only 2 instances of potential infusion reactions occurred in the 545 rapid infusions (0.36%; 95% confidence interval [CI], 0.22%-11.01%; 3% of patients) administered in the prospective group compared with 1 documented infusion reaction (0.19%; 95% CI, 0.0%-11.47%; 2% of patients) in the retrospective group (odds ratio, 0.65; 95% CI, 0.01-12.93; P = 0.99).

CONCLUSIONS

This study suggests that rapid infusion of infliximab over 1 hour is not associated with an increased risk of infusion reactions when compared with standard 2- to 3-hour infusions and can be safely used in children with no previous reaction to standard infusions to treat inflammatory bowel disease and other autoimmune diseases.

Proactive Therapeutic Drug Monitoring of TNF Antagonists in Inflammatory Bowel Disease

BACKGROUND

Proactive therapeutic drug monitoring (TDM) to titrate tumor necrosis factor (TNF) antagonists has emerged recently as a tool to routinely monitor drug concentration to achieve target levels in patients with quiescent inflammatory bowel disease (IBD).

METHODS

The purpose of the present review article was to present available data exploring the concept of proactive TDM.

RESULTS

While several observational studies have identified an association between proactive TDM and better IBD outcomes, 2 randomized controlled studies did not confirm this advantage.

CONCLUSIONS

Based on the evidence to date, proactive TDM cannot be recommended in daily practice. However, analysis is hampered by the low level of evidence for the cutoffs used and the need for point-of-care assays. Regarding economic issues and de-escalating strategies, proactive TDM may have several future indications in IBD. Exploratory studies on proactive TDM with newly available biologic agents in IBD are also awaited.

Effects of medicines used to treat gastrointestinal diseases on the pharmacokinetics of coadministered drugs: a PEARRL Review

Objectives

Drugs used to treat gastrointestinal diseases (GI drugs) are widely used either as prescription or over-the-counter (OTC) medications and belong to both the 10 most prescribed and 10 most sold OTC medications worldwide. The objective of this review article is to discuss the most frequent interactions between GI and other drugs, including identification of the mechanisms behind these interactions, where possible.

Key findings

Current clinical practice shows that in many cases, these drugs are administered concomitantly with other drug products. Due to their metabolic properties and mechanisms of action, the drugs used to treat gastrointestinal diseases can change the pharmacokinetics of some coadministered drugs. In certain cases, these interactions can lead to failure of treatment or to the occurrence of serious adverse events. The mechanism of interaction depends highly on drug properties and differs among therapeutic categories. Understanding these interactions is essential to providing recommendations for optimal drug therapy.

Summary

Interactions with GI drugs are numerous and can be highly significant clinically in some cases. While alterations in bioavailability due to changes in solubility, dissolution rate, GI transit and metabolic interactions can be (for the most part) easily identified, interactions that are mediated through other mechanisms, such as permeability or microbiota, are less well-understood. Future work should focus on characterising these aspects.

Anti-TNF Levels in Cord Blood at Birth are Associated with Anti-TNF Type

BACKGROUND AND AIMS

Pregnancy guidelines for women with inflammatory bowel disease [IBD] provide recommendations regarding anti-TNF cessation during pregnancy, in order to limit foetal exposure. Although infliximab [IFX] leads to higher anti-TNF concentrations in cord blood than adalimumab [ADA], the recommendations are similar. We aimed to demonstrate the effect of anti-TNF cessation during pregnancy on foetal exposure, for IFX and ADA separately.

METHODS

We conducted a prospective single-center cohort study. Women with IBD, using IFX or ADA, were followed-up during pregnancy. In case of sustained disease remission, anti-TNF was stopped in the third trimester. At the birth, the anti-TNF concentration was measured in the cord blood. A linear regression model was developed to demonstrate anti-TNF concentration in cord blood at birth. In addition, outcomes such as disease activity, pregnancy outcomes and 1-year health outcomes of infants were collected.

RESULTS

We included 131 pregnancies that resulted in a live birth [73 IFX, 58 ADA]. At birth, 94 cord blood samples were obtained [52 IFX, 42 ADA], showing significantly higher levels of IFX than ADA [p < 0.0001]. Anti-TNF type and stop week were used in the linear regression model. During the third trimester, IFX transportation over the placenta increased exponentially; however, ADA transportation was limited and increased in a linear fashion. Overall, health outcomes were comparable.

CONCLUSIONS

Our linear regression model shows that ADA may be continued longer during pregnancy, because transportation over the placenta is lower than for IFX. This may reduce relapse risk of the mother, without increasing foetal anti-TNF exposure.

Therapeutic drug monitoring of tumour necrosis factor inhibitors in the management of chronic inflammatory diseases

Tumour necrosis factor inhibitor therapy has drastically changed the management of chronic inflammatory diseases. Some important drawbacks that can cause loss of response during treatment with these drugs are related to their large individual variability, the disease burden and the formation of antidrug antibodies that increase its clearance. Therapeutic drug monitoring of these drugs is not yet recommended by all scientific societies, and if so, only in patients with inflammatory symptoms. Proactive therapeutic drug monitoring represents a new strategy with many potential clinical benefits, including the prevention of immunogenicity, a reduction in the need for rescue therapy and greater durability of tumour necrosis factor inhibitor treatment. The review is based on a systematic search of the literature for controlled trials, systematic reviews, experimental studies, guideline papers and cohort studies addressing the best practice in tumour necrosis factor inhibitor therapeutic drug monitoring. Although there is ample evidence supporting the use of therapeutic drug monitoring in clinical practice to achieve better outcomes, some challenges have been detected. Many studies are focused on finding solutions for the lack of standardization of analytical methods to measure tumour necrosis factor inhibitor and antidrug antibodies concentrations. Other challenges are development of effective cost-saving proactive algorithms to identify optimal drug concentrations and the research on the role of antidrug antibodies, especially in the management and prevention of loss of response. Therapeutic drug monitoring of tumour necrosis factor inhibitor offers a rational approach to the optimization of the treatment of chronic inflammatory disease. Although prospective controlled trials yield little conclusive evidence of its benefits, there is growing acceptance of its value in clinical practice.

Policy Options for Infliximab Biosimilars in Inflammatory Bowel Disease Given Emerging Evidence for Switching

Biosimilars are becoming increasingly available internationally as patents expire on the originator biologic drugs they are intended to copy. Although substitution policies seen with generic drugs are being considered as a means to reduce expenditures on biologics, some biosimilars pose particular challenges in that the act of substitution may eventually lead to increased rates of therapeutic failure. As evidence requirements from regulators do not directly address this challenge, switch trials of biosimilars have emerged that may provide further answers. Using infliximab in inflammatory bowel disease as an example, we critically examine emerging evidence from two key switch trials (NOR-SWITCH and NCT020968610) and discuss the clinical and economic implications of these and what policy options may be most reasonable for payers. Options include reimbursing biosimilars for only newly diagnosed patients, using product-listing agreements to manage uncertainty, or using tiered co-payments or other incentives to promote biosimilar use.

Immunoassay methods used in clinical studies for the detection of anti-drug antibodies to adalimumab and infliximab

We examined the assay formats used to detect anti-drug antibodies (ADA) in clinical studies of the anti-tumour necrosis factor (TNF) monoclonal antibodies adalimumab and infliximab in chronic inflammatory disease and their potential impact on pharmacokinetic and clinical outcomes. Using findings of a recent systematic literature review of the immunogenicity of 11 biological/biosimilar agents, we conducted an ancillary qualitative review of a subset of randomized controlled trials and observational studies of the monoclonal antibodies against anti-TNF factor adalimumab and infliximab. Among studies of adalimumab and infliximab, the immunoassay method used to detect antibodies was reported in 91 of 111 (82%) and 154 of 206 (75%) adalimumab and infliximab studies, respectively. In most adalimumab and infliximab studies, an enzyme-linked immunosorbent assay or radioimmunoassay was used [85 of 91 (93%) and 134 of 154 (87%), respectively]. ADA incidence varied widely among assays and inflammatory diseases (adalimumab, 0-87%; infliximab, 0-79%). Pharmacokinetic and clinical outcomes were only reported for ADA-positive patients in 38 of 91 (42%) and 61 of 154 (40%) adalimumab and infliximab studies, respectively. Regardless of assay format or biological used, ADA formation was associated with lower serum concentrations, reduced efficacy and elevated rates of infusion-related reactions. Consistent with previous recommendations to improve interpretation of immunogenicity data for biologicals, greater consistency in reporting of assay methods and clinical consequences of ADA formation may prove useful. Additional standardization in immunogenicity testing and reporting, application of modern, robust assays that satisfy current regulatory expectations and implementation of international standards for marketed products may help to improve our understanding of the impact of immunogenicity to biologics.

Systematic review of anti-drug antibodies of IL-17 inhibitors for psoriasis

Three main biologics target the IL-17 pathway; these include secukinumab, ixekizumab, brodalumab, all of which are approved for treatment of moderate-to-severe plaque psoriasis. We performed a systematic review of the literature to determine if IL-17 inhibitors are prone to develop anti-drug antibodies (ADA) and how efficacy of treatment is influenced. A total of 14 papers were reviewed. Only one secukinumab trial detected treatment-emergent ADA in 4 out of 996 (0.41%) patients during the 52-week treatment period. Two of these patients (1 on 150-mg retreatment as needed and 1 on 150-mg fixed interval) were found to have neutralizing antibodies; however, they were not associated with decreased efficacy. One paper reported ADAs against ixekizumab. One out of 1150 (9%) developed titers to ixekizumab after receiving 160-mg-loading dose followed by 80 mg every 2 weeks. Nineteen out of 1150 (1.7%) developed high titer (>1:1280) which impacted clinical outcomes. Three studies did detect ADA against brodalumab; however, none were neutralizing. It is difficult to draw a conclusion from our findings given the variability in ADA development. Most trials did not develop ADA, and if they did, the majority of the time they were not neutralizing. Only ixekizumab showed decreased efficacy, but no increased adverse events in cases with neutralizing ADA.

Should we use vedolizumab as mono or combo therapy in ulcerative colitis?

Randomized controlled trials comparing the efficacy of vedolizumab monotherapy with combination therapy of vedolizumab and an immunomodulator in patients with ulcerative colitis (UC) are lacking. Emerging pharmacokinetic data indicate that vedolizumab concentrations correlate with clinical outcomes, although the correlation may be less strong for vedolizumab compared with an anti-TNF agents. Associations between concomitant use of immunomodulators and decreased immunogenicity of vedolizumab have been reported, but this does not appear to translate into enhanced therapeutic effect of combination therapy, at least not based on present data. However, data are sparse and often based on post-hoc analyses. Future comparative effectiveness studies of patients with UC, naïve to vedolizumab as well as immunomodulators, are needed. This might be of specific relevance for subgroups of UC patients, such as young men and the elderly, in whom combination versus monotherapy therapy may have a different risk-benefit ratio, given the risk of malignancy associated with immunomodulators.

A New Venue of TNF Targeting

The first Food and Drug Administration-(FDA)-approved drugs were small, chemically-manufactured and highly active molecules with possible off-target effects, followed by protein-based medicines such as antibodies. Conventional antibodies bind a specific protein and are becoming increasingly important in the therapeutic landscape. A very prominent class of biologicals are the anti-tumor necrosis factor (TNF) drugs that are applied in several inflammatory diseases that are characterized by dysregulated TNF levels. Marketing of TNF inhibitors revolutionized the treatment of diseases such as Crohn’s disease. However, these inhibitors also have undesired effects, some of them directly associated with the inherent nature of this drug class, whereas others are linked with their mechanism of action, being pan-TNF inhibition. The effects of TNF can diverge at the level of TNF format or receptor, and we discuss the consequences of this in sepsis, autoimmunity and neurodegeneration. Recently, researchers tried to design drugs with reduced side effects. These include molecules with more specificity targeting one specific TNF format or receptor, or that neutralize TNF in specific cells. Alternatively, TNF-directed biologicals without the typical antibody structure are manufactured. Here, we review the complications related to the use of conventional TNF inhibitors, together with the anti-TNF alternatives and the benefits of selective approaches in different diseases.

Therapeutic Drug Monitoring in Pediatric Inflammatory Bowel Disease

PURPOSE OF REVIEW

Therapeutic drug monitoring (TDM) has emerged as a useful tool to optimize the use of drug therapies in adults with inflammatory bowel disease (IBD), including both Crohn's disease (CD) and ulcerative colitis (UC), especially during the use of biological therapies, for which the pharmacokinetics and pharmacodynamics are highly variable among patients. Fewer data exist in children. This review examines the current literature on TDM in pediatric IBD.

RECENT FINDINGS

Drug clearance is affected by a number of patient and disease factors. For thiopurines, adjusting dosing by monitoring 6-thioguanine (6TGN) and 6-methylmercaptopurine ((6MMP) levels is demonstrated to maximize response and minimize toxicity, while monitoring metabolite levels when treating with anti-tumor necrosis factor (anti-TNF) remain controversial. While in adults the use of TDM in the setting of loss of response to anti-TNF therapy is established, in children, only a small number of studies exist, but these too have encouraging results. There are however, conflicting data regarding the optimal timing of TDM, comparing "reactive" monitoring and "proactive" monitoring. No such data exist in pediatrics. TDM is cost-effective, and dose reduction may represent a safety benefit. There are limited adult data for use of TDM for the newer biologics, vedolizumab and ustekinumab, but early results suggest similarly promising utility. The use of TDM in pediatric IBD is increasing in clinical practice, with similar efficacy to adults demonstrated in children with loss of response to anti-TNF therapy. More prospective studies are needed in children to examine proactive monitoring and utility of TDM with newer biologics.

Secondary Loss of Response to Infliximab in Pediatric Crohn Disease: Does It Matter How and When We Start?

OBJECTIVES

A significant proportion of children with Crohn disease develop a secondary loss of response (LOR) to infliximab. Our aim was to study the impact of initial treatment strategies on secondary LOR.

METHODS

We reviewed the medical records of children with Crohn disease who received scheduled maintenance infliximab therapy for at least 12 months. We compared children who developed LOR with those who did not; with regards to their clinical and laboratory parameters, disease phenotype, and treatment strategy before developing LOR.

RESULTS

A total of 73 children (median age at diagnosis 11 (2-16) years, 41 boys) who had received a median duration of 33 (13-110) months of infliximab therapy were included in the final analysis. LOR was seen in 25(34.2%). Demographic variables, disease phenotype (age, disease location, and behavior), inflammatory parameters, and pediatric Crohn disease activity index at induction with infliximab were similar between both groups. Children with LOR had a significantly greater number of flares of the disease when compared to those who did not have LOR (4 [1-8] vs 2 [1-5] P = 0.03). The choice of the concomitant immunomodulator-methotrexate (11/29 [37.9%]) versus azathioprine (11/36 [30.5%]) (P = 0.6) did not affect LOR rates. The median time-lag between diagnosis and induction with infliximab was significantly longer in children with LOR as compared to those who did not have an LOR (28 [4-90] months vs 12.5 [1-121] months, P = 0.004).

CONCLUSION

Early use of infliximab in pediatric Crohn disease is associated with a decrease in secondary LOR. The type of concomitant immunomodulator used does not make a difference to LOR rates.

ACG Clinical Guideline: Management of Crohn's Disease in Adults

Crohn's disease is an idiopathic inflammatory disorder of unknown etiology with genetic, immunologic, and environmental influences. The incidence of Crohn's disease has steadily increased over the past several decades. The diagnosis and treatment of patients with Crohn's disease has evolved since the last practice guideline was published. These guidelines represent the official practice recommendations of the American College of Gastroenterology and were developed under the auspices of the Practice Parameters Committee for the management of adult patients with Crohn's disease. These guidelines are established for clinical practice with the intent of suggesting preferable approaches to particular medical problems as established by interpretation and collation of scientifically valid research, derived from extensive review of published literature. When exercising clinical judgment, health-care providers should incorporate this guideline along with patient's needs, desires, and their values in order to fully and appropriately care for patients with Crohn's disease. This guideline is intended to be flexible, not necessarily indicating the only acceptable approach, and should be distinguished from standards of care that are inflexible and rarely violated. To evaluate the level of evidence and strength of recommendations, we used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. The Committee reviews guidelines in depth, with participation from experienced clinicians and others in related fields. The final recommendations are based on the data available at the time of the production of the document and may be updated with pertinent scientific developments at a later time.

Combination Immunosuppression in IBD

Whether to use biologic treatment for inflammatory bowel disease as monotherapy or in combination with immunosuppressives has been a matter of debate in the last 2 decades. Combination therapy was not superior in any of the registration trials for Crohn's disease and ulcerative colitis for TNF antagonists, vedolizumab, or ustekinumab. It needs to be mentioned, though, that none of these trials were powered to detect such differences, and that many patients entered the trial after having failed conventional immunosuppressives.Postmarketing studies revealed that patients on background immunosuppression have a lower risk of immunogenicity (often resulting in infusion/injection reactions) than patients on monotherapy. In the SONIC and UC-SUCCESS trials, superiority of the combination azathioprine-infliximab was demonstrated in Crohn's disease and ulcerative colitis, respectively. This trial design has not been used with any other biologic for IBD, so far. Meanwhile, it has also become clear that combination treatment with TNF antagonists is associated with increased toxicity, mainly infections, but also malignancy such as lymphoproliferative disease. This toxicity could perhaps be reduced by using lower doses of immunosuppressives, a strategy that has been shown to be equally potent in reducing immunogenicity. Additionally, combination treatment could be used for a limited period of time (12 months or even shorter) since most immunogenicity develops in the beginning of the biologic treatment. Patients who develop anti-drug-antibodies later on can often be rescued by reintroduction of thiopurines or methotrexate.In summary, combination treatment is certainly beneficial with infliximab, at least in the first 12 months of treatment. With other TNF antagonists, vedolizumab, and ustekinumab, the available data do not offer clear guidance. In patients without increased risk of toxicity, and certainly in those with limited treatment options, it may be wise to offer combination treatment with all biologics for the time being and at least during the initiation phase.

Full Interchangeability in Regard to Immunogenicity Between the Infliximab Reference Biologic and Biosimilars CT-P13 and SB2 in Inflammatory Bowel Disease

BACKGROUND

Infliximab (IFX) biosimilars CT-P13 and SB2 have comparable efficacy, safety, and immunogenicity to the originator Remicade (RMC). However, concerns about cross-switching patients between the 3 brands were raised in the absence of cross reactivity data between them. We aimed to determine whether antibodies to infliximab (ATI) in inflammatory bowel disease (IBD) patients cross-react with RMC, CT-P13, and SB2.

METHODS

Based on previous ATI status, samples from 34 patients participating in the BIOSIM01 study (13 RMC, 9 CT-P13, and 12 switchers) were selected. Patients were treated with either RMC only, or CT-P13 only, or with RMC switched to CT-P13. Additionally, 28 IFX-naïve patients were assayed as controls. In total, 180 samples were analyzed. ATI trough levels were measured in parallel with 3 different bridging Enzyme Linked Immunosorbent Assays constructed using the 3 drugs. Spearman's coefficient and percentages of agreement were used to study the correlation between each assay.

RESULTS

In total, 76 samples out of 152 IFX-treated patient samples were ATI-positive (30 RMC, 14 CT-P13, and 32 switchers). All resulted ATI-positive when either CT-P13 or SB2 bridging assays were used. The overall percentage of agreement was 100% when compared either with CT-P13 or SB2 assays. No significant differences were found among ATI levels and coefficients (Spearman's 0.98 to 1.0, P < 0.0001).

CONCLUSIONS

ATI of RMC-treated, CT-P13-treated or RMC to CT-P13 switched patients show full cross-reactivity with CT-P13 and SB2. Findings suggest that immunodominant epitopes in the reference and CT-P13 drugs are equally present in SB2. Data support full interchangeability between biosimilars in regard to immunogenicity.

Clinical effectiveness and cost-effectiveness of use of therapeutic monitoring of tumour necrosis factor alpha (TNF-α) inhibitors [LISA-TRACKER® enzyme-linked immunosorbent assay (ELISA) kits, TNF-α-Blocker ELISA kits and Promonitor® ELISA kits] versus standard care in patients with Crohn's disease: systematic reviews and economic modelling

BACKGROUND AND OBJECTIVES

Systematic reviews and economic modelling of clinical effectiveness and cost-effectiveness of therapeutic monitoring of tumour necrosis factor alpha (TNF-α) inhibitors [using LISA-TRACKER^® enzyme-linked immunosorbent assay (ELISA) kits (Theradiag, Marne La Vallee, France, or Alpha Laboratories, Heriot, UK), TNF-α-Blocker ELISA kits (Immundiagnostik AG, Bensheim, Germany) and Promonitor^® ELISA kits (Proteomika, Progenika Biopharma, Bizkaia, Spain)] versus standard care for Crohn's disease (CD).

METHODS

Multiple electronic databases were searched from inception to December 2014 in order to identify primary studies and meta-analyses.

POPULATION

Patients with moderate to severe active CD treated with infliximab (IFX) (Remicade^®, Merck Sharp & Dohme Ltd, Kenilworth, NJ, USA) or adalimumab (ADA) (Humira^®, AbbVie Inc., North Chicago, IL, USA).

INTERVENTION

Monitoring of serum anti-TNF-α (IFX or ADA) and/or of anti-drug antibody levels using test assays with a test-treatment algorithm.

COMPARATOR

Standard care.

OUTCOMES

Any patient-related outcome, test agreement and cost-effectiveness estimates. The quality assessments used recognised checklists (Quality Assessment of Diagnostic Accuracy Studies-2, Cochrane, Philips and Consolidated Health Economic Evaluation Reporting Standards). Evidence was synthesised using narrative review and meta-analysis. A Markov model was built in TreeAge Pro 2013 (TreeAge Software, Inc., Williamstown, MA, USA). The model had a 4-week cycle and a 10-year time horizon, adopted a NHS and Personal Social Services perspective and used a linked evidence approach. Costs were adjusted to 2013/14 prices and discounted at 3.5%.

RESULTS

We included 68 out of 2434 and 4 out of 2466 studies for the clinical effectiveness and cost-effectiveness reviews, respectively. Twenty-three studies comparing test methods were identified. Evidence on test concordance was sparse and contradictory, offering scant data for a linked evidence approach. Three studies [two randomised controlled trials (RCTs) and one retrospective observational study] investigated outcomes following implementation of a test algorithm. None used the specified commercial ELISA immunoassay test kits. Neither of the two RCTs demonstrated clinical benefit of a test-treatment regimen. A meta-analysis of 31 studies to estimate test accuracy for predicting clinical status indicated that 20-30% of test results are likely to be inaccurate. The four cost-effectiveness studies suggested that testing results in small cost reductions. In the economic analysis the base-case analysis showed that standard practice (no testing/therapeutic monitoring with the intervention tests) was more costly and more effective than testing for IFX. Sensitivity and scenario analyses gave similar results. The probabilistic sensitivity analysis indicated a 92% likelihood that the 'no-testing' strategy was cost-effective at a willingness to pay of £20,000 per quality-adjusted life-year.

STRENGTHS AND LIMITATIONS

Rigorous systematic reviews were undertaken; however, the underlying evidence base was poor or lacking. There was uncertainty about a linked evidence approach and a lack of gold standard for assay comparison. The only comparative evidence available for economic evaluation was for assays other than the intervention assays.

CONCLUSIONS

Our finding that testing is not cost-effective for IFX should be viewed cautiously in view of the limited evidence. Clinicians should be mindful of variation in performance of different assays and of the absence of standardised approaches to patient assessment and treatment algorithms.

FUTURE WORK RECOMMENDATIONS

There is substantial variation in the underlying treatment pathways and uncertainty in the relative effectiveness of assay- and test-based treatment algorithms, which requires further investigation. There is very little research evidence on ADA or on drug monitoring in children with CD, and conclusions on cost-effectiveness could not be reached for these.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014015278.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Anti-infliximab antibody concentrations can guide treatment intensification in patients with Crohn's disease who lose clinical response

BACKGROUND

The presence of antibodies towards infliximab (ATI) is associated with lower infliximab (IFX) trough concentrations and loss of response. IFX treatment intensification is effective for restoring response in most, but not all patients with Crohn's disease (CD).

AIM

To compare outcome, pharmacokinetics and immunogenicity of treatment intensification strategies in patients with CD who lost clinical response to IFX.

METHODS

A retrospective cohort study was conducted, including 103 patients with CD who lost clinical response during IFX maintenance therapy and therefore received a double dose IFX (10 mg/kg) and/or a next infusion after a shortened interval. IFX and ATI concentrations were measured in consecutive trough samples, just before (T0) and after (T+1) treatment intensification.

RESULTS

Clinical response (physicians' global assessment) and biological response and remission (CRP) were restored in 63%, 42% and 24% of patients (evaluated at T+1). Treatment intensification increased IFX trough concentrations from 1.2 μg/mL [0.3-3.6] at T0 to 3.6 μg/mL [0.5-10.2] at T+1 (P < .0001). Using a drug tolerant assay, ATI were detected in the T0 sample of 47% of patients. ATI negatively impacted the achieved IFX trough concentration (Spearman r -0.57, P < .0001) and the probability of clinical response (P = 0.034) at T+1. When ATI were quantifiable but <282 ng/mL eq. at T0, combined interval shortening and dose doubling was more effective for restoring therapeutic IFX trough concentrations (≥3 μg/mL at T+1) than dose doubling alone, which in turn was more effective than interval shortening alone (P < .001).

CONCLUSION

Antibodies towards infliximab can guide clinical decision-making on treatment intensification.

Immunogenicity of biologics in inflammatory bowel disease

Crohn's disease and ulcerative colitis are chronic inflammatory disorders of the gastrointestinal tract. Treatment options include biologic therapies; however, a proportion of patients lose response to biologics, partly due to the formation of anti-drug antibodies (ADAbs). Concomitant immunosuppressive agents reduce the development of ADAbs. This review article aims to assess the immunogenicity of biologic therapies and their clinical implications. A comprehensive literature search was conducted for articles published January 2009 to August 2015 reporting immunogenicity to adalimumab (ADM), certolizumab pegol (CZP), golimumab, infliximab (IFX), ustekinumab, and vedolizumab in inflammatory bowel disease (IBD). Eligible articles were reviewed and quality assessed by independent reviewers. Overall, 122 publications reporting 114 studies were assessed. ADAbs were reported for all agents, but the percentage of patients developing ADAbs was extremely variable, with the highest (65.3%) being for IFX administration to patients with IBD. ADAb presence was frequently associated with a reduction in primary efficacy and a loss of response, and, for IFX, an increase in adverse events (AEs). Lower serum levels of ADM, CZP and IFX were seen in ADAbs-positive rather than ADAbs-negative patients; pharmacokinetic data were unavailable for other therapies. Little information was available regarding the timing of ADAb development; studies reported their detection from as early as 10-14 days up to months after treatment initiation. Biologic therapies carry an intrinsic risk of immunogenicity, although reported rates of ADAbs vary considerably. The clinical implications of immunogenicity are a concern for effective treatment; further research, particularly into the more recently approved biologics, is required.

The Addition of an Immunosuppressant After Loss of Response to Anti-TNFα Monotherapy in Inflammatory Bowel Disease: A 2-Year Study

BACKGROUND

The addition of an immunosuppressant (IM) after loss of response to anti-TNFα monotherapy is an emerging strategy of therapeutic optimization in patients with inflammatory bowel disease (IBD). However, few clinical data have been reported to date. We aimed to evaluate the efficacy and safety of this selective combination therapy in patients with IBD.

METHODS

All consecutive patients with loss of response to anti-TNFα monotherapy despite an intensive dose optimization who added an IM from October 2014 to October 2016 were entered into a prospective database.

RESULTS

Among 630 patients treated with anti-TNFα agents during the study period, 46 (7.3%) added an IM. A total of 31 patients (67.4%) were treated with an intravenous anti-TNFα (infliximab, as originator or biosimilar), while 15 (32.6%) were treated with a subcutaneous anti-TNFα agent (10 adalimumab and 5 golimumab). The mean duration of follow-up was 12.8 ± 7.3 months. Twenty-one patients (45.7%) remained on combination therapy at the end of follow-up: 15 (32.6%) maintained a steroid-free remission, and 6 (13.0%) achieved a clinical response. In patients who experienced treatment success, the median value of C-reactive protein decreased from baseline to the end of follow-up (13.2 vs 3.0, P = 0.01; normal values <5 mg/L). Adverse events leading to treatment discontinuation were reported in 8 out of 46 patients (17.4%).

CONCLUSIONS

In the largest cohort on this argument reported to date, the addition of an IM was an effective and safe optimization strategy after loss of response to anti-TNFα monotherapy. Low doses of IM were sufficient to achieve a clinical response.

Development of Clinical Prediction Models for Surgery and Complications in Crohn's Disease

BACKGROUND AND AIMS

Crohn's disease-related complications account for a substantial proportion of inflammatory bowel disease-associated health care expenditure. Identifying patients at risk for complications may allow for targeted use of early therapeutic interventions to offset this natural course. We aimed to develop risk prediction models for Crohn's disease-related surgery and complications.

METHODS

Using data from the Randomised Evaluation of an Algorithm for Crohn's Disease cluster-randomised clinical Trial [REACT], which involved 1898 patients from 40 community practices, separate prediction models were derived and internally validated for predicting Crohn's disease-related surgery and disease-related complications [defined as the first disease-related surgery, hospitalisation, or complication within 24 months]. Model performance was assessed in terms of discrimination and calibration, decision curves, and net benefit analyses.

RESULTS

There were 130 [6.8%] disease-related surgeries and 504 [26.6%] complications during the 24-month follow-up period. Selected baseline predictors of surgery included age, gender, disease location, Harvey-Bradshaw Index [HBI] score, stool frequency, antimetabolite or 5-aminosalicylate use, and the presence of a fistula, abscess, or abdominal mass. Selected predictors of complications included those same factors for surgery, plus corticosteroid or anti-tumour necrosis factor use, but excluded 5-aminosalicylate use. Discrimination ability, as measured by validated c-statistics, was 0.70 and 0.62 for the surgery and complication models, respectively. Score charts and nomograms were developed to facilitate future risk score calculation.

CONCLUSIONS

Separate risk prediction models for Crohn's disease-related surgery and complications were developed using clinical trial data involving community gastroenterology practices. These models could be used to guide Crohn's disease management. External validation is warranted.

Dosing down and then discontinuing biologic therapy in rheumatoid arthritis: a review of the literature

AIM

To review the published studies that dose down and then discontinue biologic therapy in patients with rheumatoid arthritis (RA), particularly concerning the criteria for such dosing and the impact on clinical outcomes.

METHODS

Published studies conducted in patients with RA that sequentially decreased the dose and then discontinued therapy were included if one or more of the following biologic disease modifying antirheumatic drugs (bDMARDs) was evaluated: abatacept, adalimumab, certolizumab, etanercept, golimumab, infliximab, rituximab or tocilizumab.

RESULTS

Five studies qualified for inclusion. The populations of patients with RA were heterogeneous among the studies; patients were required to have low disease activity (LDA) or to be in remission prior to dose titration. Approximately 25-65% of patients successfully decreased and in some cases, discontinued the bDMARD. However, the flare rate was higher than for the patients who remained on a standard dose. The only variable that predicted relapse in more than one study was down-titration of the bDMARD dose.

CONCLUSION

In patients who have achieved LDA or remission, down-titration and discontinuation of bDMARD therapy may be attempted, with careful monitoring. However, it is likely that some patients will flare, and it is not known how to predict these patients.

Switching maintenance infliximab therapy to biosimilar infliximab in inflammatory bowel disease patients

BACKGROUND

Clinical use of biosimilar infliximab (CT-P13) in inflammatory bowel diseases (IBDs) is based on extrapolation of indication from clinical studies performed in rheumatological diseases. Only few data exist of behaviour of infliximab trough levels (TLs) and anti-drug antibodies (ADAs) during switching.

AIM

The objective of this study was to evaluate changes in TLs, ADA formation and disease activity after switching from originator infliximab to biosimilar one.

METHODS

All our IBD patients receiving maintenance infliximab therapy were switched to biosimilar infliximab. TLs and ADAs were measured before the last originator infusion and before the third biosimilar infusion. Laboratory values, disease activity indices (partial Mayo score and Harvey-Bradshaw index) and demographic data were collected from patient records.

RESULTS

A total of 62 patients were included in the final analysis (32 Crohn's disease, 30 ulcerative colitis (UC) or IBD-unclassified). No significant changes in median TLs before (5.5 mg/l) and after switching (5.5 mg/l, p = .05) occurred in the entire study group or in the Crohn's disease (CD) subgroup (5.75 and 6.5 mg/l, p = .68). However, in the subgroup of ulcerative colitis, the change in median TL was significantly different (from 5.2 to 4.25 mg/l, p = .019). Two patients developed ADAs after switching. No changes in disease activity were detected during switching and no safety concerns occurred.

CONCLUSIONS

Switching from originator to biosimilar infliximab resulted in statistically significant differences in infliximab TLs in patients with UC but not in patients with Crohn's disease. The clinical significance for this difference is doubtful and in neither group changes in disease activity occurred.

Antibodies Toward Vedolizumab Appear from the First Infusion Onward and Disappear Over Time

BACKGROUND

Vedolizumab (VDZ) has been approved for the treatment of patients with moderate-to-severe Crohn's disease and ulcerative colitis. The GEMINI trials reported a low prevalence of anti-VDZ antibodies (AVA). However, the AVA assays used in GEMINI were drug sensitive, resulting in a possible underestimation of the rate of AVA formation. This study aimed to monitor immunogenicity of VDZ in a real-life cohort using a drug-resistant AVA assay.

METHODS

Using a combination of VDZ/AVA complex precipitation and acid dissociation, a drug-resistant assay for AVA detection in the presence of high VDZ concentrations has been developed and analytically validated. The assay was applied on serum samples of 179 VDZ-treated patients with inflammatory bowel disease to evaluate the prevalence and time course of AVA.

RESULTS

A dose-response curve ranging from 25 to 1600 ng/mL using 1/125 diluted serum was obtained, allowing the detection of AVA concentrations up to 200 μg/mL of MA-VDZ19C11 equivalents, a calibrator antibody to VDZ. This assay was highly AVA specific and drug resistant. Four of 179 VDZ-treated patients (2.2%) were AVA positive and AVA were detected already after the first VDZ infusion. AVA were all transient in these patients without need for any dosage optimization. There was no correlation between VDZ and AVA concentrations in the AVA-positive samples.

CONCLUSIONS

AVA appear from the first VDZ infusion onward and disappear over time. The low prevalence of AVA suggests that immunogenicity does not influence response to treatment.

Drug survival of biologic treatments in psoriasis: a systematic review

Drug survival measures the length of time until discontinuation of a drug. The length of time a patient remains on a biologic drug is impacted by several factors such as tolerability, side effects, safety profile and effectiveness. To evaluate the long-term drug survival, data of the most commonly prescribed biologic medications used in the treatment of psoriasis, a systematic review was conducted. A literature search using PubMed, the Cochrane Library and the Cumulative Index to Nursing and Allied Health Literature from January 1 2010 to October 28 2016 identified 3734 abstracts. Of which, 36 publications with over 40,000 patients met the inclusion criteria. The median overall drug survival for ustekinumab, adalimumab, infliximab and etanercept was 38.0, 36.5, 26.6 and 24.7 months, respectively. The mean annual drug survival rate of TNF inhibitors was 70%, 57%, 51%, 45% and 41% at years-1, 2, 3, 4 and 5, respectively. The 5-year mean annual drug survival rate of ustekinumab was 87%, 78%, 70%, 71% and 51%, respectively. Based on our findings, ustekinumab appears to have a longer drug survival with lower rates of discontinuation compared to tumor necrosis factor inhibitors.

Long-term Efficacy, Safety, and Immunogenicity of Biosimilar Infliximab After One Year in a Prospective Nationwide Cohort

BACKGROUND

It has been previously shown that biosimilar infliximab CT-P13 is effective and safe in inducing remission in inflammatory bowel diseases. We report here the 1-year outcomes from a prospective nationwide inflammatory bowel disease cohort.

METHODS

A prospective, nationwide, multicenter, observational cohort was designed to examine the efficacy and safety of CT-P13 in the induction and maintenance treatment of Crohn's disease (CD) and ulcerative colitis (UC). Demographic data were collected and a harmonized monitoring strategy was applied. Clinical remission, response, and biochemical response were evaluated at weeks 14, 30, and 54, respectively. Safety data were registered.

RESULTS

Three hundred fifty-three consecutive inflammatory bowel disease (209 CD and 144 UC) patients were included, of which 229 patients reached the week 54 endpoint at final evaluation. Age at disease onset: 24/28 years (median, interquartile range: 19-34/22-39) in patients with CD/UC. Forty-nine, 53, 48% and 86, 81 and 65% of patients with CD reached clinical remission and response by weeks 14, 30, and 54, respectively. Clinical remission and response rates were 56, 41, 43% and 74, 66, 50% in patients with UC. Clinical efficacy was influenced by previous anti-tumor necrosis factor (TNF) exposure in patients with a drug holiday beyond 1 year. The mean C-reactive protein level decreased significantly in both CD and UC by week 14 and was maintained throughout the 1-year follow-up (both UC/CD: P < 0.001). Thirty-one (8.8%) patients had infusion reactions and 32 (9%) patients had infections. Antidrug antibody positivity rates were significantly higher throughout patients with previous anti-TNF exposure; concomitant azathioprine prevented antidrug antibody formation in anti-TNF-naive patients with CD.

CONCLUSIONS

Results from this prospective nationwide cohort confirm that CT-P13 is effective and safe in inducing and maintaining long-term remission in both CD and UC. Efficacy was influenced by previous anti-TNF exposure; no new safety signals were detected.

The Immunogenicity of Branded and Biosimilar Infliximab in Rheumatoid Arthritis According to Th9-Related Responses

Our objective was to evaluate the immunogenicity of branded and biosimilar infliximab by detecting changes in T-helper-9 (Th9) percentages induced by an in vitro stimulation test.

METHODS

Peripheral blood mononuclear cells collected from 55 consecutive rheumatoid arthritis (RA) outpatients (15 drug free, 20 successfully treated with branded infliximab, 20 branded infliximab inadequate responders) and 10 healthy controls were cultured, with or without 50 μg/mL of infliximab originator (Remicade^®) or 50 μg/mL of infliximab biosimilar (Remsima^®) for 18 h. Th9 lymphocytes were identified by means of flow cytometry as PU.1 and IRF4-expressing, IL-9-secreting CD4⁺ T cells. Furthermore, the markers CCR7 and CD45RA were used to distinguish naïve from memory IL-9 producer cells.

RESULTS

Under unstimulated conditions, the drug-free RA patients had the highest percentages of Th9 lymphocytes. Following stimulation with branded infliximab, the percentages of PU.1 and IRF4-expressing Th9 cells, CCR7⁺, CD45RA^- (central memory) and CCR7^-, CD45RA^- (effector memory) cells significantly increased in the group of inadequate responders, but no significant variation was observed after exposure to the biosimilar of infliximab.

CONCLUSIONS

Th9 cells seem to be involved in the immune response to the epitopes of branded, but not biosimilar, infliximab, and this may depend on the recall and stimulation of both central and effector memory cells.

Concomitant Therapy with Immunomodulator Enhances Infliximab Durability in Pediatric Inflammatory Bowel Disease

BACKGROUND

Data on long-term durability of infliximab (IFX) and outcomes of concomitant therapy with immunomodulator in pediatric inflammatory bowel disease are limited.

METHODS

Children with inflammatory bowel disease who received IFX ± immunomodulator were retrospectively reviewed. Predictors of induction response were assessed using a binary logistic regression model and long-term outcomes evaluated by Cox proportional hazards model. Propensity score matching examined long-term efficacy of concomitant therapy in patients with Crohn's disease (CD).

RESULTS

Among 148 patients (113 CD, 35 ulcerative colitis; median age at IFX initiation 14.09 years [interquartile range 12.16-15.65]), 91% experienced response to induction therapy; patients with CD were more likely to respond (95% versus 77%, odds ratio = 2.63, 95% confidence interval, 1.01-6.85, P = 0.048). Despite dose optimization, secondary loss of response occurred at a rate of 9.01% and 8.33% per year for patients with CD and ulcerative colitis, respectively. A Cox proportional hazards model showed that concomitant therapy >6 months significantly lowered the risk of secondary loss of response in CD (hazard ratio = 0.39, 95% confidence interval, 0.17-0.88, P = 0.025). The same trend was observed in ulcerative colitis but did not reach significance. A higher proportion of patients on IFX monotherapy stopped IFX because of loss of response or infusion reactions (55% versus 21%, P < 0.001). Propensity score analysis of patients with CD showed significantly higher steroid-free remission rates for concomitant versus monotherapy at 1 year (78% versus 54%, P = 0.020) and 2 years (68% versus 46%, P = 0.044), and durability of response (P = 0.022).

CONCLUSIONS

These data demonstrate sustained efficacy of IFX in a cohort of pediatric patients with inflammatory bowel disease with durability of response enhanced by concomitant therapy.

Less Anti-infliximab Antibody Formation in Paediatric Crohn Patients on Concomitant Immunomodulators

OBJECTIVES

To evaluate the effect of immunomodulators on formation of antibodies to infliximab (ATI) in paediatric patients with Crohn disease (CD) and the association of ATI and loss of response.

METHODS

Retrospective multicentre observational study (January 2009-December 2014) among Dutch children with CD treated with infliximab (IFX). ATI formation was analysed with Chi-square test and time-to-ATI formation with Kaplan-Meier and log-rank test.

RESULTS

A total of 229 children were identified. ATIs were measured in 162 patients (70.7%) and 25 (15%) developed ATIs: 6 of 62 (10%) on continuous combined immunosuppression (CCI), 11 of 81 (14%) on early combined immunosuppression (ECI), and 8 of 19 (42%) on IFX monotherapy. ATI formation was higher in patients on IFX monotherapy compared to CCI (P = 0.003) and ECI (P = 0.008), whereas no significant difference was found between CCI and ECI. Sixteen out of 25 patients (64%) with ATIs had loss of response, compared with 32 of 137 patients (19%) without ATIs (P < 0.00002, log rank 0.02). Among patients treated with ECI, 10 of 55 (18%) developed ATIs within the first 12 months, compared to 1 of 26 (4%) after more than 12 months.

CONCLUSIONS

In children with CD combination therapy is associated with significant reduction of antibody formation and prolonged effectivity compared to IFX monotherapy. ECI for at least 12 months, followed by IFX monotherapy, may be an equally effective alternative to CCI.

IMPORTANCE OF MEASURING LEVELS OF INFLIXIMAB IN PATIENTS TREATING INFLAMMATORY BOWEL DISEASE IN A BRAZILIAN COHORT

BACKGROUND

Crohn's disease and ulcerative colitis are chronic inflammatory bowel diseases. In such pathologies, there is an increased production of alpha tumor necrosis factor (TNF-α). Patients, in whom the conventional immunosuppressant treatment fails, require the use of immunobiological therapy, such as anti-TNF-α, a monoclonal antibody. Infliximab is an anti-TNF-α drug, a chimerical immunoglobulin, with a murine component, which is responsible for the generation of immunogenicity against the drug and formation of anti-TNF-α antibodies. The presence of anti-drug antibodies may be responsible for adverse events and reduction of the drug's effectiveness. Patients with inflammatory bowel diseases undergoing therapy with biological medication, such as infliximab, can relapse overtime and this may not be translated into clinical symptoms. Thus, there is a need for a method to evaluate the efficacy of the drug, through the measurement of serum infliximab levels, as well as antibodies research.

OBJECTIVE

This study aimed to measure serum infliximab levels and anti-infliximab antibodies in patients with inflammatory bowel diseases post-induction phase and during maintenance therapy, and describe the therapeutic modifications that took place based on the serum levels results.

METHODS

It was a retrospective study, that included forty-five patients, with a total of 63 samples of infliximab measurement.

RESULTS

Twenty-one patients had an adequate infliximab serum level, 31 had subtherapeutic levels and 11 had supratherapeutic levels. Seven patients had their medication suspended due to therapeutic failure or high levels of antibodies to infliximab.

CONCLUSION

In conclusion, only a third of the patients had adequate infliximab levels and 36% presented with subtherapeutic levels at the end of the induction phase. Therapy optimization occurred based in about 46% of the samples results, demonstrating the importance of having this tool to help the clinical handling of patients with inflammatory bowel diseases ongoing biologic therapy.

Primary and secondary nonresponse to infliximab: mechanisms and countermeasures

INTRODUCTION

Primary and secondary non-response to infliximab are common in patients with inflammatory bowel disease and remain a management challenge in clinical practice. Areas covered: This article describes the epidemiology, mechanisms and risk factors for primary and secondary nonresponse to infliximab in patients with inflammatory bowel disease. Data on proactive and reactive therapeutic drug monitoring are examined in this review. An algorithm for evaluation and management of non-response to infliximab is provided. Preventative measures are also discussed. Relevant articles were identified after a literature search using PubMed. Search terms included 'infliximab', 'loss of response', 'immunogenicity', and 'drug monitoring'. References of identified articles were also reviewed to identify additional references. Expert opinion: A common cause for primary and secondary non-response include inadequate dosing of infliximab; inadequate dosing can be identified through assessment of drug and anti-drug antibody levels. Therapeutic drug monitoring should be done in patients losing response to infliximab. Use of drug monitoring proactively is still under debate.

Effects of Combination Therapy With Immunomodulators on Trough Levels and Antibodies Against Tumor Necrosis Factor Antagonists in Patients With Inflammatory Bowel Disease: A Meta-analysis

BACKGROUND & AIMS

It is not clear whether combination therapy with immunomodulators affects the immunogenicity of tumor necrosis factor (TNF) antagonists in patients with inflammatory bowel disease. We performed a meta-analysis to quantify the effects of combined immunomodulator therapy on the presence of antibodies against TNF antagonists (antidrug antibodies [ADAs]) and trough levels of anti-TNF agents.

METHODS

We systematically searched publication databases for studies that reported prevalence of ADAs in patients who received anti-TNF agents. Raw data from studies that met the inclusion criteria were pooled to determine effect estimates. We performed subgroup and metaregression analyses to determine the level of heterogeneity among study outcomes.

RESULTS

We analyzed findings from 35 studies that met inclusion criteria (results reported from 6790 patients with inflammatory bowel disease). The pooled risk ratio for formation of ADAs in patients receiving combined therapy with immunomodulators, versus that of patients receiving anti-TNF monotherapy, was 0.49 (95% confidence interval, 0.41-0.59; P < .001). However, the pooled analysis did not demonstrate a significant difference in trough levels of anti-TNF agents between patients with versus without concurrent use of immunomodulators (standardized mean difference, 0.11; 95% confidence interval, 0.19-0.41; P = .47). Subgroup analyses of patients treated with different TNF antagonists revealed no difference in the formation of ADAs (P = .50 for interaction); the protective effect of immunomodulators did not differ with type of drug patients were given (methotrexate vs thiopurines), or assay for ADA. We observed heterogeneity only among studies of patients with ulcerative colitis (I² = 76%). Funnel plot and Egger test analyses indicated publication bias in the studies (P = .001).

CONCLUSIONS

In a meta-analysis of published studies, we associated combined treatment with immunomodulators with reduced risk of formation of antibodies against TNF antagonists in patients with inflammatory bowel disease.

Strategies for overcoming anti-tumor necrosis factor drug antibodies in inflammatory bowel disease: Case series and review of literature

Anti-tumor necrosis factor (TNF) biologics are currently amongst the most widely used and efficacious therapies for inflammatory bowel disease (IBD). The development of therapeutic drug monitoring for infliximab and adalimumab has allowed for measurement of drug levels and antidrug antibodies. This information can allow for manipulation of drug therapy and prediction of response. It has been shown that therapeutic anti-TNF drug levels are associated with maintenance of remission, and development of antidrug antibodies is predictive of loss of response. Studies suggest that a low level of drug antibodies, however, can at times be overcome by dose escalation of anti-TNF therapy or addition of an immunomodulator. We describe a retrospective case series of twelve IBD patients treated at the University of California-Irvine, who were on infliximab or adalimumab therapy and were found to have detectable but low-level antidrug antibodies. These patients underwent dose escalation of the drug or addition of an immunomodulator, with subsequent follow-up drug levels obtained. Eight of the twelve patients (75%) demonstrated resolution of antidrug antibodies, and were noted to have improvement in disease activity. Though data regarding overcoming low-level anti-TNF drug antibodies remains somewhat limited, cases described in the literature as well as our own experience suggest that this may be a viable strategy for preserving the use of an anti-TNF drug. Low-level anti-TNF drug antibodies may be overcome by dose escalation and/or addition of an immunomodulator, and can allow for clinical improvement in disease status. Therapeutic drug monitoring is an important tool to guide this strategy.

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.

Colonic Phenotypes Are Associated with Poorer Response to Anti-TNF Therapies in Patients with IBD

BACKGROUND

Although anti-tumor necrosis factor (TNF) agents are effective in patients with inflammatory bowel disease (IBD), many patients either do not respond to anti-TNF treatment or lose response over time. The aim of this study was to determine factors associated with response to anti-TNF therapy in IBD.

METHODS

Patients with Crohn's disease (CD) or ulcerative colitis who had consented to participate in a genetics registry and been treated with anti-TNF agents were evaluated retrospectively and categorized as primary nonresponders or secondary nonresponders. We evaluated clinical, serological, and genetic characteristics associated with primary nonresponse or time to loss of response to anti-TNF agents.

RESULTS

We included 314 CD (51 [16.2%] primary nonresponders and 179 [57.0%] secondary nonresponders) and 145 subjects with ulcerative colitis (43 [29.7%] primary nonresponders and 74 [51.0%] secondary nonresponders). Colonic involvement (P = 0.017; odds ratio = 8.0) and anti-TNF monotherapy (P = 0.017; odds ratio = 4.9) were associated in a multivariate analysis with primary nonresponse to anti-TNF agents in CD. In addition, higher anti-nuclear cytoplasmic antibody levels (P = 0.019; hazard ratio = 1.01) in CD, anti-nuclear cytoplasmic antibody positivity (P = 0.038; hazard ratio = 1.6) in ulcerative colitis, and a positive family history of IBD (P = 0.044; hazard ratio = 1.3) in all patients with IBD were associated with time to loss of response to anti-TNF agents. Furthermore, various known IBD susceptibility single-nucleotide polymorphisms and additional variants in immune-mediated genes were shown to be associated with primary nonresponse or time to loss of response.

CONCLUSIONS

Our results may help to optimize the use of anti-TNF agents in clinical practice and position these therapies appropriately as clinicians strive for a more personalized approach to managing IBD.

Interactions Between Therapeutic Proteins and Small Molecules: The Shared Role of Perpetrators and Victims

Therapeutic proteins (TPs) are becoming increasingly important as therapeutic agents. A consequence of expanding their clinical indications is coadministration with well-established small-molecule drugs (sMDs), which could lead to unpredictable effects. According to the existing regulatory guidance, the development of an sMD includes the evaluation of potential drug-drug interactions (DDIs). For TPs, only a few drug interaction studies have been published. Limited clinically relevant models, long half-lives, and complex elimination pathways are among the associated difficulties.

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.

Combination therapy for inflammatory bowel disease

Biologic therapies such as infliximab and adalimumab have become mainstays of treatment for inflammatory bowel disease. Early studies suggested that combination therapy (CT) with infliximab and an immunomodulator drug such as azathioprine may help optimize biologic pharmacokinetics, minimize immunogenicity, and improve outcomes. The landmark SONIC trial in Crohn's disease and the UC SUCCESS trial in ulcerative colitis demonstrated CT with infliximab and azathioprine to be superior to monotherapy with either agent alone at inducing clinical remission in treatment naïve patients with moderate to severe disease. However, many unanswered questions linger. The role of CT in non-naive patients as well as the optimal duration of CT remains unknown. The effectiveness of CT with alternate biologics and/or alternate immunomodulators is not as clear, and it is unknown whether SONIC's conclusions can be extrapolated beyond infliximab and azathioprine. Also looming are the risks of CT including opportunistic infection and malignancy; specifically, lymphoma. This review lays out the evidence as it pertains to the risks and benefits of CT as well as the areas that require further research. With this information in hand, the practitioner may develop a treatment strategy that best suits each individual patient.

A Real-life Population Pharmacokinetic Study Reveals Factors Associated with Clearance and Immunogenicity of Infliximab in Inflammatory Bowel Disease

BACKGROUND

Several factors influencing the pharmacokinetics of infliximab (IFX) in inflammatory bowel disease (IBD) have been identified. We studied the impact of patient, disease, and treatment characteristics on clearance and immunogenicity of IFX in a real-world patient-with-IBD cohort.

METHODS

Serum concentrations of IFX and antibodies to IFX (ATIs) were measured in patients with IBD at a single center using an enzyme-linked immunosorbent assay and radioimmunoassay. Patient, disease, and treatment characteristics were retrospectively collected along with laboratory values. Pharmacokinetics and ATI titer were analyzed simultaneously by nonlinear mixed-effects modeling.

RESULTS

Nine hundred ninety-seven IFX concentrations and 756 ATI measurements from 332 patients with IBD (253 Crohn's disease and 79 ulcerative colitis) were included. Mean (SD) IFX dose was 5.47 ± 1.33 mg/kg. ATIs were detected in 75/332 (23%) patients; insufficient exposure below an IFX trough level of 3 μg/mL was the most predictive factor of developing ATI and resulted in a 4-fold increased risk of ATI development. ATI titer was a better predictor of IFX clearance than ATI as a dichotomous parameter. ATI titers >30 AU/mL were consistently associated with undetectable IFX concentrations. IFX clearance was affected by body weight (40-149 kg) ranging from 0.27 to 0.53 L/d, serum albumin (2-5.4 g/dL) from 0.93 to 0.24 L/d, and titers of ATIs (0-53,000 AU/mL) from 0.36 L/d to 15.93 L/d (P < 0.001). Previously biologic-treated patients exhibited a higher clearance of IFX.

CONCLUSIONS

IFX exposure below 3 μg/mL increases risk of ATIs. Identification of influential pharmacokinetics and ATI factors improves prediction of IFX levels, potentially allowing individualized dosing and cost reduction.

Safety of treatments for inflammatory bowel disease: Clinical practice guidelines of the Italian Group for the Study of Inflammatory Bowel Disease (IG-IBD)

Inflammatory bowel diseases are chronic conditions of unknown etiology, showing a growing incidence and prevalence in several countries, including Italy. Although the etiology of Crohn's disease and ulcerative colitis is unknown, due to the current knowledge regarding their pathogenesis, effective treatment strategies have been developed. Several guidelines are available regarding the efficacy and safety of available drug treatments for inflammatory bowel diseases. Nevertheless, national guidelines provide additional information adapted to local feasibility, costs and legal issues related to the use of the same drugs. These observations prompted the Italian Group for the Study of Inflammatory Bowel Disease (IG-IBD) to establish Italian guidelines on the safety of currently available treatments for Crohn's disease and ulcerative colitis. These guidelines discuss the use of aminosalicylates, systemic and low bioavailability corticosteroids, antibiotics (metronidazole, ciprofloxacin, rifaximin), thiopurines, methotrexate, cyclosporine A, TNFα antagonists, vedolizumab, and combination therapies. These guidelines are based on current knowledge derived from evidence-based medicine coupled with clinical experience of a national working group.

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.