Novel bispecific nanobody mitigates experimental intestinal inflammation in mice by targeting TNF-α and IL-23p19 bioactivities

BACKGROUND

Inflammatory bowel diseases (IBDs) pose significant challenges in terms of treatment non-response, necessitating the development of novel therapeutic approaches. Although biological medicines that target TNF-α (tumour necrosis factor-α) have shown clinical success in some IBD patients, a substantial proportion still fails to respond.

METHODS

We designed bispecific nanobodies (BsNbs) with the ability to simultaneously target human macrophage-expressed membrane TNF-α (hmTNF-α) and IL-23. Additionally, we fused the constant region of human IgG1 Fc (hIgG1 Fc) to BsNb to create BsNb-Fc.  Our study encompassed in vitro and in vivo characterization of BsNb and BsNb-Fc.

RESULTS

BsNb-Fc exhibited an improved serum half-life, targeting capability and effector function than BsNb. It's demonstrated that BsNb-Fc exhibited superior anti-inflammatory effects compared to the anti-TNF-α mAb (infliximab, IFX) combined with anti-IL-12/IL-23p40 mAb (ustekinumab, UST) by Transwell co-culture assays. Notably, in murine models of acute colitis brought on by 2,4,6-trinitrobenzene sulfonic acid（TNBS) and dextran sulphate sodium (DSS), BsNb-Fc effectively alleviated colitis severity. Additionally, BsNb-Fc outperformed the IFX&UST combination in TNBS-induced colitis, significantly reducing colon inflammation in mice with colitis produced by TNBS and DSS.

CONCLUSION

These findings highlight an enhanced efficacy and improved biostability of BsNb-Fc, suggesting its potential as a promising therapeutic option for IBD patients with insufficient response to TNF-α inhibition.

KEY POINTS

A bispecific nanobody (BsNb) was created to target TNF-α and IL-23p19, exhibiting high affinity and remarkable stability. BsNb-Fc inhibited the release of cytokines in CD4+T cells during co-culture experiments. BsNb-Fc effectively alleviated colitis severity in mouse model with acute colitis induced by DSS or TNBS, outperforming the IFX&UST combination.

Empagliflozin attenuates intestinal inflammation through suppression of nitric oxide synthesis and myeloperoxidase activity in in vitro and in vivo models of colitis

Inflammatory bowel diseases (IBD) are characterized by chronic and relapsing inflammation affecting the gastrointestinal (GI) tract. The incidence and prevalence of IBD are relatively high and still increasing. Additionally, current therapeutic strategies for IBD are not optimal. These facts urge todays' medicine to find a novel way to treat IBD. Here, we focused on the group of anti-diabetic drugs called gliflozins, which inhibit sodium glucose co-transporter type 2 (SGLT-2). Numerous studies demonstrated that gliflozins exhibit pleiotropic effect, including anti-inflammatory properties. In this study, we tested the effect of three gliflozins; empagliflozin (EMPA), dapagliflozin (DAPA), and canagliflozin (CANA) in in vitro and in vivo models of intestinal inflammation. Our in vitro experiments revealed that EMPA and DAPA suppress the production of nitric oxide in LPS-treated murine RAW264.7 macrophages. In in vivo part of our study, we showed that EMPA alleviates acute DSS-induced colitis in mice. Treatment with EMPA reduced macro- and microscopic colonic damage, as well as partially prevented from decrease in tight junction gene expression. Moreover, EMPA attenuated biochemical inflammatory parameters including reduced activity of myeloperoxidase. We showed that SGLT-2 inhibitors act as anti-inflammatory agents independently from their hypoglycemic effects. Our observations suggest that gliflozins alleviate inflammation through their potent effects on innate immune cells.

Performance of a New Rapid Point-of-Care Test for Infliximab Levels in Patients with Inflammatory Bowel Disease: A Comparison to ELISA

BACKGROUND

Therapeutic drug monitoring of infliximab levels in patients with inflammatory bowel disease (IBD) optimizes patients' treatment. The reference technique is based on enzyme-linked immunosorbent assay (ELISA) although point of care (POC) assays are being developed.

AIMS

To assess the performance of a new rapid immunochromatographic POC assay (Promonitor Quick IFX) compared with ELISA technique to measure infliximab levels in patients with IBD.

METHODS

A prospective, observational, unicentric study was performed on capillary blood samples from patients with IBD before infliximab infusion (trough levels). Infliximab levels and anti-infliximab antibodies were measured using the ELISA technique (Promonitor IFX) and the POC assay. Correlation between both techniques was assessed by Pearson's coefficient. Quantitative differences were evaluated by Bland-Altman analysis. Samples were stratified according to infliximab therapeutic ranges (< 3 μg/mL, 3-8 μg/mL, and > 8 μg/mL).

RESULTS

A total of 135 experimental samples were assessed. Infliximab levels showed a high correlation between POC and ELISA tests (r = 0.84, P < 0.001). The mean difference between tests was 1.46 μg/mL (P < 0.001), being minimal for concentrations < 8 μg/mL. POC and ELISA assays showed an overall concordance of 87.4%. Most samples were in the same therapeutic range, which lead to equivalent therapeutic decisions. POC and ELISA assays detected the presence of anti-infliximab antibodies in 2.2% and 3.7% of the samples, respectively.

CONCLUSIONS

POC assay results in blood samples from patients with IBD were comparable to those obtained with the reference ELISA technique. The POC assay could be considered for routine testing based on its ease of use and rapidity.

Efficacy and safety of vedolizumab in the treatment of patients with inflammatory bowel disease: A systematic review and meta‑analysis of randomized controlled trials

Few studies have thoroughly assessed the efficacy and safety of vedolizumab (VDZ) in the treatment of inflammatory bowel disease (IBD). Therefore, this systematic review and meta-analysis was performed to further evaluate this association. PubMed, Embase, and the Cochrane databases were searched until April 2022. Randomized controlled trials (RCTs) evaluating the efficacy and safety of VDZ in the treatment of IBD were included. The risk ratio (RR) and 95% confidence intervals (CI) were estimated for each outcome using a random effects model. A total of 12 RCTs, including 4,865 patients, met the inclusion criteria. In the induction phase, VDZ was more effective than placebo for patients with ulcerative colitis and Crohn's disease (CD) in clinical remission (RR=2.09; 95% CI=1.66-2.62) and clinical response (RR=1.54; 95% CI=1.34-1.78). In the maintenance therapy group, VDZ reached higher clinical remission (RR=1.98; 95% CI=1.58-2.49) and clinical response (RR=1.78; 95% CI=1.40-2.26) rates compared with the placebo group. VDZ particularly improved clinical remission (RR=2.07; 95% CI=1.48-2.89) and clinical response (RR=1.84; 95% CI=1.54-2.21) in patients with TNF antagonist failure. In terms of corticosteroid-free remission, VDZ was also more effective than placebo in patients with IBD (RR=1.98; 95% CI=1.51-2.59). In Crohn's patients, VDZ was more effective than placebo in terms of mucosal healing (RR=1.78; 95% CI=1.27-2.51). With respect to adverse events, VDZ significantly reduced the risk of IBD exacerbation compared with the placebo (RR=0.60; 95% CI=0.39-0.93; P=0.023). However, when compared with the placebo, VDZ increased the risk of nasopharyngitis in patients with CD (RR=1.77; 95% CI=1.01-3.10; P=0.045). No significant differences in other adverse events were observed. Although there might be underlying risk, such as selection bias, in the present study it can be safely concluded that VDZ is a safe and effective biological agent for IBD, particularly for patients with TNF antagonist failure.

Dose intensification strategy influences infliximab pharmacokinetics but not clinical response after the same number of doses

BACKGROUND

The optimal infliximab dose intensification strategy to address secondary loss of response (LOR) remains unclear. This study aimed to compare clinical and pharmacokinetic outcomes following (i) upfront infliximab re-induction with (ii) ongoing 6-weekly dose interval shortening (DIS), after the same number of doses.

METHODS

A prospective parallel cohort study of inflammatory bowel disease patients who required infliximab dose intensification for secondary LOR using (i) re-induction (i.e., repeat 5 mg/kg 0, 2, 6-week dosing) followed by 8-weekly maintenance or (ii) 6-weekly 5 mg/kg DIS was undertaken. Week 32 clinical response was the primary outcome, with secondary evaluation of infliximab pharmacokinetics and predictors of response.

RESULTS

Of 104 patients, 54 underwent re-induction, and 50 underwent 6-weekly DIS; 43 per cohort had clinically active disease, with comparable baseline infliximab levels (2.03 vs 2.02 ug/mL, P = 0.83). Clinical response was similar across re-induction and DIS cohorts at weeks 12 (69.8 vs 65.1%) and 32 (53.5 vs 62.8%, each P > 0.50); however, both strategies demonstrated distinct pharmacokinetic profiles at weeks 6 (18.45 vs 5.36 ug/mL, P < 0.01), 12 (8.94 vs 5.96 ug/mL, P = 0.02) and 30 (3.89 vs 6.35 ug/mL, P = .0.02). In multivariable analyses, objectively verified active disease at baseline (OR 12.92, 95% CI [1.84-90.84], P = 0.01), subtherapeutic week 6 infliximab levels (OR 0.12, 95% CI [0.01, 0.99], P = 0.049) and week 12 clinical response (OR 5.44, 95% CI [1.20-19.97], P = 0.04) were associated with week 32 response, as were week 2 infliximab levels (OR 1.34, 95% CI [1.02-1.47], P = 0.04) following re-induction. Following re-induction, week 2 infliximab levels <15.6 ug/mL (AUROC 0.76, 95% CI [0.54-0.99], P < 0.05) predicted nonresponse at week 32.

CONCLUSION

Dose intensification strategy impacted immediate and sustained infliximab levels but not clinical response. Upfront intensification was associated with short-term pharmacokinetic advantages, including predictors of response, that diminished with time. Hence, when applying upfront dose intensification, clinicians should consider continuing intensified dosing to sustain early pharmacokinetic advantages based on predictors of (non)response.

Microbial changes in stool, saliva, serum, and urine before and after anti-TNF-α therapy in patients with inflammatory bowel diseases

Inflammatory bowel diseases (IBD), including Crohn's disease and ulcerative colitis, are chronic immune-mediated intestinal inflammatory disorders associated with microbial dysbiosis at multiple sites, particularly the gut. Anti-tumor necrosis factor-α (TNF-α) agents are important treatments for IBD. We investigated whether microbiome changes at multiple sites can predict the effectiveness of such treatment in IBD. Stool, saliva, serum, and urine biosamples were collected from 19 IBD patients before (V1) and 3 months after (V2) anti-TNF-α treatment, and 19 healthy subjects (control). Microbiota analysis was performed using extracellular vesicles (EVs; all four sample types) and next-generation sequencing (NGS; stool and saliva). The stool, using NGS analysis, was the only sample type in which α-diversity differed significantly between the IBD and control groups at V1 and V2. Relative to non-responders, responders to anti-TNF-α treatment had significantly higher levels of Firmicutes (phylum), Clostridia (class), and Ruminococcaceae (family) in V1 stool, and Prevotella in V1 saliva. Non-responders had significantly higher V2 serum and urine levels of Lachnospiraceae than responders. Finally, Acidovorax caeni was detected in all V1 sample types in responders, but was not detected in non-responders. Microbiome changes at multiple sites may predict the effectiveness of anti-TNF-α treatment in IBD, warranting further research.

Therapeutic drug monitoring of anti-TNF drugs: an overview of applicability in daily clinical practice in the era of treatment with biologics in juvenile idiopathic arthritis (JIA)

BACKGROUND

Anti-tumor necrosis factor (TNF) drugs have improved the prognosis for juvenile idiopathic arthritis (JIA) significantly. However, evidence for individual treatment decisions based on serum anti-TNF drug levels and the presence of anti-drug antibodies (ADAbs) in children is scarce. We aimed to assess if anti-TNF drug levels and/or ADAbs influenced physician's treatment decisions in children with JIA.

METHODS

Patients' records in our center were retrospectively screened for measurements of anti-TNF drug levels and ADAbs in children with JIA using etanercept, adalimumab or infliximab. Clinical characteristics and disease activity were retrieved from patient charts.

RESULTS

We analyzed 142 measurements of anti-TNF drug levels in 65 children with JIA. Of these, ninety-seven (68.3%) were trough concentrations. N = 14/97 (14.4%) of these showed trough concentrations within the therapeutic drug range known for adults with RA and IBD. ADAbs against adalimumab were detected in seven patients and against infliximab in one patient. Seven (87,5%) of these ADAb-positive patients had non-detectable drug levels. A flowchart was made on decisions including rational dose escalation, stopping treatment in the presence of ADAbs and undetectable drug levels, showing that 45% of measurements influenced treatment decisions, which concerned 65% of patients (n = 42/65).

CONCLUSIONS

In the majority of patients, measurement of anti-TNF drug levels led to changes in treatment. A wide variation of anti-TNF drug levels was found possibly due to differences in drug clearance in different age groups. There is need for determination of therapeutic drug ranges and pharmacokinetic curves for anti-TNF and other biologics in children with JIA.

Monoclonal Antibody Monitoring: Clinically Relevant Aspects, A Systematic Critical Review

Monoclonal antibody (mAb) therapy does not usually lead to a clinical response in all patients and resistance may increase over time after repeated mAb administration. This lack or loss of response to the treatment may originate from different and little-known epigenetic, biomolecular, or pathophysiological mechanisms, although an inadequate serum concentration is perhaps the most likely cause, even if not widely recognized and investigated yet. Patient factors that influence the pharmacokinetics (PK) of a mAb should be taken into account. Multiple analyses of patient-derived PK data have identified various factors influencing the clearance of mAbs. These factors include the presence of antidrug antibodies, low serum albumin, high serum levels of C-reactive protein, high body weight, and gender differences among others. The same clearance processes involved in systemic clearance after intravenous administration are also involved in local first-pass catabolism after subcutaneous administration of mAbs. Therapeutic drug monitoring has been proposed as a way to understand and respond to the variability in clinical response and remission. For both classes of mAbs with anti-inflammatory and antitumor effects, dose-guided optimization based on the measurement of serum concentrations in individual patients could be the next step for a personalized and targeted mAb therapy.

Assessing adherence to infusion-based biologic therapies in patients with inflammatory bowel disease

BACKGROUND

The intravenous biologics infliximab and vedolizumab are effective long-term therapies for inflammatory bowel disease (IBD). Though highly effective, suboptimal adherence may result in loss of response and adverse sequelae. The extent and outcomes of suboptimal adherence with intravenous biologics, including in IBD, requires further evaluation.

OBJECTIVES

To ascertain adherence to infliximab and vedolizumab infusions, and determine factors associated with poorer adherence within an IBD cohort.

METHODS

A retrospective single-centre cohort study of IBD patients, assessing adherence to infliximab and vedolizumab over 2 years (July 1, 2017 to June 30, 2019) was conducted. Medical and pharmacy dispensing records were used to determine date of infusion. Adherence was assessed using the continuous, multiple interval measure of medication gaps (CMG). Objectively measured disease remission was achieved if one or more of endoscopic remission, faecal calprotectin <100 μg/mL and/or CRP <5 mg/mL occurred within 3 months of end of follow-up. Bivariate analysis and multiple linear regression elucidated factors associated with poorer adherence.

RESULTS

Of 193 IBD patients, 132 (68.4%) had Crohn's disease. One hundred and thirty six (70.5%) patients received infliximab and 57 (29.5%) received vedolizumab with a median 13 [IQR 11-14] doses administered per patient over 2 years. Adherence according to CMG was similar between infliximab and vedolizumab groups (median 1.5% vs 1.2%, p = 0.31). In multiple linear regression analysis male sex, shorter IBD duration and clinic non-attendances were each associated with poorer adherence (Beta 4.69, 3.90, 3.56 respectively, p < 0.05) and objective disease remission was inversely associated with poorer adherence (Beta -3.27, p < 0.05).

CONCLUSION

There was a wide range of adherence to biologic infusions in this IBD cohort with poorer adherence associated with patient related factors. Conversely, objectively measured remission was strongly associated with adherence. This emphasises the need for targeted interventions to improve adherence and monitoring, and mitigate treatment delays.

Treat-to-target approach in the management of inflammatory Bowel disease

With the advent of biologic and small molecule therapies, there has been a substantial change in the treatment of inflammatory bowel disease. These advances have had a great impact in preventing disease progression, intestinal damage and, therefore, have contributed to a better quality of life. Discordance between symptom control and mucosal healing has been demonstrated. This has led to the search for new disease control targets. The treat to target strategy, based on expert recommendations and now a randomized controlled trial, has determined that clinical and endoscopic remission should be the goal of therapy. Biomarkers (fecal calprotectin) can be a surrogate target. Although histological healing has shown benefits, there is inadequate evidence and inadequate therapy for that to be a fixed goal at this time. This review will focus on therapeutic goals, according to the evidence currently available, and evaluate strategies to achieve them.

Ligation of the Intersphincteric Fistula Tract and Endorectal Advancement Flap for High Perianal Fistulas in Crohn's Disease: A Retrospective Cohort Study

BACKGROUND AND AIMS

Ligation of the intersphincteric fistula tract [LIFT] and advancement flap [AF] procedures are well-established, sphincter-preserving procedures for closure of high perianal fistulas. As surgical fistula closure is not commonly offered in Crohn's disease patients, long-term data are limited. This study aims to evaluate outcomes after LIFT and AF in Crohn's high perianal fistulas.

METHODS

All consecutive Crohn's disease patients ≥18 years old treated with LIFT or AF between January 2007 and February 2018 were included. The primary outcome was clinical healing and secondary outcomes included radiological healing, recurrence, postoperative incontinence and Vaizey Incontinence Score.

RESULTS

Forty procedures in 37 patients [LIFT: 19, AF: 21, 35.1% male] were included. A non-significant trend was seen towards higher clinical healing percentages after LIFT compared to AF [89.5% vs 60.0%; p = 0.065]. Overall radiological healing rates were lower for both approaches [LIFT 52.6% and AF 47.6%]. Recurrence rates were comparable: 21.1% and 19.0%, respectively. In AF a trend was seen towards higher clinical healing percentages when treated with anti-tumour necrosis factor/immunomodulators [75.0% vs 37.5%; p = 0.104]. Newly developed postoperative incontinence occurred in 15.8% after LIFT and 21.4% after AF. Interestingly, 47.4% of patients had a postoperatively improved Vaizey Score [LIFT: 52.9% and AF: 42.9%]. The mean Vaizey Score decreased from 6.8 [SD 4.8] preoperatively to 5.3 [SD 5.0] postoperatively [p = 0.067].

CONCLUSIONS

Both LIFT and AF resulted in satisfactory closure rates in Crohn's high perianal fistulas. However, a discrepancy between clinical and radiological healing rates was found. Furthermore, almost half of the patients benefitted from surgical intervention with respect to continence.

Optimizing Antitumor Necrosis Factor Treatment in Pediatric Inflammatory Bowel Disease With Therapeutic Drug Monitoring

Biological agents have revolutionized inflammatory bowel disease treatment but primary nonresponse and secondary loss of response are common with resulting adverse outcomes. Clinical trials demonstrated an association between serum drug concentrations, as well as the presence of antidrug antibodies, and loss-of-response. Therapeutic drug monitoring (TDM), defined as the evaluation of drug concentrations and antidrug antibodies, is appearing as a strategy to optimize treatment and take full advantage from these drugs. TDM appears to be a promising tool in clinical practice, especially in pediatric patients, who have pronounced fluctuations in the pharmacokinetics of the drugs.The authors present a literature review about antitumor necrosis factor therapy optimization based on personalized treatment strategies according to TDM and possible strategies to recapture loss of response, including an algorithm for practical management.

A virtual clinic increases anti-TNF dose intensification success via a treat-to-target approach compared with standard outpatient care in Crohn's disease

BACKGROUND

Virtual clinics represent a novel model of care in inflammatory bowel disease. Their effectiveness in promoting high quality use of biologic therapy and facilitating a treat-to-target approach is unknown.

AIM

To evaluate clinical and process-driven outcomes in a virtual clinic compared to standard outpatient care amongst patients receiving intensified anti-TNF therapy for secondary loss of response.

METHODS

We performed a retrospective multi-centre, parallel, observational cohort study of Crohn's disease patients receiving intensified anti-TNF therapy for secondary loss of response. Objective assessments of disease activity and anti-TNF trough levels at secondary loss of response and during subsequent 6-month semesters, were compared longitudinally between virtual clinic and standard outpatient care cohorts. The primary endpoint was treatment success, with appropriateness of dose intensification, tight disease monitoring and treatment de-escalation representing secondary outcomes.

RESULTS

Of 149 patients with similar baseline characteristics, 69 were managed via a virtual clinic and 80 via standard outpatient care. There were higher rates of treatment success in the virtual clinic cohort (60.9 vs 35.0%, P < 0.002). Rates of appropriate dose intensification (82.6% vs 40.0%, P < 0.001), biomarker remission (faecal calprotectin P = 0.002), tight-disease monitoring (84.1% vs 28.8%, P < 0.001) and treatment de-escalation (21.3% vs 10.0%, P = 0.027) also favoured the virtual clinic cohort.

CONCLUSION

This study favoured a virtual clinic-led model-of-care over standard outpatient care in facilitating treatment success as part of an effective treat-to-target approach in Crohn's disease. A virtual clinic model-of-care also improved treatment outcomes and quality of use of intensified anti-TNF therapy through processes that promoted appropriate dose intensification and tight-disease monitoring, while encouraging more frequent dose de-escalation.

A nationwide survey on therapeutic drug monitoring of anti-tumour necrosis factor agents for inflammatory bowel disease

BACKGROUND

Routine therapeutic drug monitoring (TDM) during treatment with anti-tumour necrosis factor (anti-TNF) agents in inflammatory bowel disease may increase treatment efficacy and cost-effectiveness, and reduce the risk of loss of response.

AIMS

To assess the current use of anti-TNF agent TDM, including trough concentration and anti-drug antibodies, among gastroenterology practitioners in New Zealand.

METHODS

A web-based survey was delivered to gastroenterologists and advanced trainees in New Zealand, identified by the New Zealand Society of Gastroenterology.

RESULTS

The response rate was 36% (48/134). Adalimumab was the most common initial anti-TNF agent used (78%, infliximab 22%). Ninety-three percent of those who completed the survey used TDM, mainly in cases of non-response or loss or response. Most respondents (93% and 83% for adalimumab and infliximab, respectively) measured trough concentrations within 24 h prior to the next administration. In patients in clinical remission but with endoscopic inflammation on anti-TNF agents, 72% would measure drug concentrations. In the presence of anti-drug antibodies, 45% would add an immunomodulator in patients with active disease and 47% would add an immunomodulator in patients in remission. With low trough concentrations, 77% would make no changes if the patient was in remission, and 75% would increase the dose in case of active disease.

CONCLUSION

TDM was routinely used among inflammatory bowel disease gastroenterology clinicians who responded to this survey. However, interpretation of results and decision-making is variable, suggesting more guidance is required.

Population Pharmacokinetics and Exposure-Response Modeling of Golimumab in Adults With Moderately to Severely Active Ulcerative Colitis

PURPOSE

Golimumab is a fully human monoclonal antibody to tumor necrosis factor-α and is indicated for the treatment of moderately to severely active ulcerative colitis (UC). This study analyzed the population pharmacokinetic (PK) properties of golimumab and exposure-response for efficacy and safety, using data from combined Phase II/III UC studies.

METHODS

Data on serum golimumab concentration following IV and subcutaneous (SC) administration were fitted simultaneously using nonlinear mixed-effects modeling for the development of a population PK model. Logistic regression models were used for assessing relationships between serum golimumab concentrations and clinical efficacy outcomes in SC induction and maintenance studies. The percentages of patients developing infections, serious infections, and serious adverse events were assessed by golimumab exposure metric quartiles.

FINDINGS

The PK properties of golimumab are well described by a 2-compartment model with first-order absorption and elimination. Typical values of PK parameters in a 70-kg patient were clearance, 0.544 L/d; central and peripheral compartment V_d, 3.43 and 2.27 L, respectively; and intercompartmental clearance, 0.291 L/d. Golimumab t_1/2 was 10.5 days; bioavailability following SC administration was 52.2%. Body weight, anti-golimumab antibodies, serum albumin, C-reactive protein, and alkaline phosphatase affected golimumab disposition. A positive exposure-response relationship was established between golimumab concentration and efficacy outcomes. No apparent correlation between golimumab exposure and rate of infections, serious infections, or serious adverse events was observed in patients receiving golimumab 50 or 100 mg SC every 4 weeks through 1 year.

IMPLICATIONS

Body weight, serum albumin, and anti-golimumab antibodies explain some of the variability observed in the PK properties of golimumab, and exposure-response findings support the recommended posology of golimumab in UC. ClinicalTrials.gov identifiers: NCT00488774, NCT00487539, and NCT00488631.

Infliximab and adalimumab concentrations and anti-drug antibodies in inflammatory bowel disease control using New Zealand assays

BACKGROUND

Therapeutic drug monitoring of anti-tumour necrosis factor (TNF) drugs and anti-drug antibodies (ADA) is now recommended in the treatment of inflammatory bowel disease. However, assay types and drug concentration thresholds are still debated.

AIM

To correlate inflammatory bowel disease activity in a New Zealand cohort with trough concentrations of infliximab and adalimumab, and ADA using locally developed competitive-binding enzyme-linked immunosorbent assays (ELISA) to establish threshold concentrations.

METHODS

Patients with ulcerative colitis (UC) and Crohn disease (CD) from Christchurch and Dunedin on anti-TNF drugs >12 weeks were enrolled. Trough blood samples were assayed for drug and ADA concentrations. Other data included quality of life, blood count, C-reactive protein, albumin, renal function and disease activity indices.

RESULTS

Of 103 patients, 53 were on infliximab (36 CD, 15 UC and 2 unclassified) and 50 adalimumab (48 CD and 2 UC). Median (range) infliximab and adalimumab concentrations were 10.5 (0-41) and 9.61 mg/L (0-30). CD remission, Crohn Disease Activity Index <150, correlated with infliximab and adalimumab concentration in CD (infliximab, P = 0.03; adalimumab, P = 0.04), with too few UC patients for analysis. Receiver operator curve analysis suggested a threshold value of 5.1 mg/L for distinguishing active disease from remission for infliximab and 7.3 mg/L for adalimumab in CD. Of 13 patients with infliximab <2 mg/L, 10 were ADA positive by homogeneous mobility shift assay (HMSA), including five with neutralising antibodies using ELISA. Of six with adalimumab <2 mg/L, three were ADA positive using HMSA, including one with neutralising antibodies.

CONCLUSION

Using the New Zealand ELISA assay, threshold concentrations of 5 mg/L for infliximab and 7 mg/L for adalimumab are suggested to aid dosing decisions, consistent with results internationally. Both neutralising (ELISA) and non-neutralising ADA (HMSA) are associated with low drug concentrations.

Therapeutic drug monitoring with vedolizumab in inflammatory bowel disease

Therapeutic drug monitoring (TDM) is a useful tool for decision-making process in patients with inflammatory bowel disease (IBD) treated with anti TNF-α drugs, especially when experiencing loss of response. Growing evidences support the existence of exposure-response relationship with vedolizumab, but the utility and the appropriate use of TDM in clinical practice is still under debate. In this review, we summarize all evidences supporting a TDM-guided approach for patients treated with vedolizumab, suggesting three potential scenarios: 1) early prediction of long-term outcomes; 2) verifying the best strategy in case of loss of response; 3) maximizing therapeutic efficacy during maintenance treatment. Vedolizumab through concentrations <20 µg/mL at week 6 and >12 µg/mL seem to be associated with more favorable outcomes. No comparative studies have been conducted so far to demonstrate the advantage of adopting a TDM-guided versus an empirical approach for managing primary or secondary nonresponses. The frequency of antibodies to vedolizumab detection is quite low (up to 4% in pivotal trials), suggesting, unlike of anti TNF-α agents, a low probability of experiencing an immune-mediated pharmacokinetic failure in clinical practice. Future prospective and controlled studies are warranted to establish the guidance on the use of a TDM-guided approach with vedolizumab in clinical practice.

Therapeutic drug monitoring-based dosing of TNF inhibitors in inflammatory bowel disease: the way forward?

Introduction: Secondary loss of response to anti-tumor necrosis factor (TNF) therapy remains a challenge in the clinical management of inflammatory bowel disease (IBD) patients. A frequently observed reason for secondary loss of response to TNF blockers is inadequate drug exposure and sub-therapeutic serum drug concentrations. Areas covered: This review presents an overview of recent research on therapeutic drug monitoring (TDM)-based dosing with anti-TNF agents in IBD. The role of reactive and proactive TDM and different approaches on how to optimize anti-TNF treatment are discussed. Expert opinion: Due to variations within and between patients, the 'one size fits all' theory does not apply to all IBD patients receiving anti-TNF agents. Timing of TDM (i.e. reactive versus proactive) is a matter of debate. Both strategies might optimize anti-TNF treatment, although most trials did not show a clinical benefit compared to conventional dosing up to now. So-called dashboard systems might have an additive value in the optimization of anti-TNF treatment, since these tools enable clinicians to really personalize anti-TNF treatment.

The performance of Remicade®-optimized quantification assays in the assessment of Flixabi® levels

BACKGROUND

The advent of Remicade® biosimilars, Remsima®, Inflectra® and, more recently, Flixabi®, has brought along the potential to decrease the costs associated with this therapy, therefore increasing its access to a larger group of patients. However, and in order to assure a soft transition, one must make sure the assays and algorithms previously developed and optimized for Remicade perform equally well with its biosimilars. This study aimed to: (a) validate the utilization of Remicade-optimized therapeutic drug monitoring assays for the quantification of Flixabi; and (b) determine the existence of Remicade, Remsima and Flixabi cross-immunogenicity.

METHODS

Healthy donors' sera spiked with Remicade, Remsima and Flixabi were quantified using three different Remicade-quantification assays, and the reactivity of anti-Remicade and anti-Remsima sera to Remicade and to its biosimilars was assessed.

RESULTS

The results show that all tested Remicade-infliximab-optimized assays measure Flixabi as accurately as they measure Remicade and Remsima: the intraclass correlation coefficients between theoretical and measured concentrations varied from 0.920 to 0.990. Moreover, the interassay agreement values for the same compounds were high (intraclass correlation coefficients varied from 0.936 to 0.995). Finally, the anti-Remicade and anti-Remsima sera reacted to the different drugs in a similar fashion.

CONCLUSIONS

The tested assays can be used to monitor Flixabi levels. Moreover, Remicade, Remsima and Flixabi were shown to have a high cross-immunogenicity, which supports their high similarity but prevents their switching in nonresponders with antidrug antibodies.

Review article: consensus statements on therapeutic drug monitoring of anti-tumour necrosis factor therapy in inflammatory bowel diseases

BACKGROUND

Therapeutic drug monitoring (TDM) in inflammatory bowel disease (IBD) patients receiving anti-tumour necrosis factor (TNF) agents can help optimise outcomes. Consensus statements based on current evidence will help the development of treatment guidelines.

AIM

To develop evidence-based consensus statements for TDM-guided anti-TNF therapy in IBD.

METHODS

A committee of 25 Australian and international experts was assembled. The initial draft statements were produced following a systematic literature search. A modified Delphi technique was used with 3 iterations. Statements were modified according to anonymous voting and feedback at each iteration. Statements with 80% agreement without or with minor reservation were accepted.

RESULTS

22/24 statements met criteria for consensus. For anti-TNF agents, TDM should be performed upon treatment failure, following successful induction, when contemplating a drug holiday and periodically in clinical remission only when results would change management. To achieve clinical remission in luminal IBD, infliximab and adalimumab trough concentrations in the range of 3-8 and 5-12 μg/mL, respectively, were deemed appropriate. The range may differ for different disease phenotypes or treatment endpoints-such as fistulising disease or to achieve mucosal healing. In treatment failure, TDM may identify mechanisms to guide subsequent decision-making. In stable clinical response, TDM-guided dosing may avoid future relapse. Data indicate drug-tolerant anti-drug antibody assays do not offer an advantage over drug-sensitive assays. Further data are required prior to recommending TDM for non-anti-TNF biological agents.

CONCLUSION

Consensus statements support the role of TDM in optimising anti-TNF agents to treat IBD, especially in situations of treatment failure.

Indicators of suboptimal tumor necrosis factor antagonist therapy in inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is refractory to treatment in one-half of patients.

AIMS

To evaluate the occurrence of suboptimal therapy among patients with IBD treated with tumor necrosis factor antagonists (anti-TNFs).

METHODS

A multinational chart review in Europe and Canada was conducted among IBD patients diagnosed with ulcerative colitis (UC) or Crohn's disease (CD) who initiated anti-TNF therapy between 2009 and 2013. The primary endpoint was the cumulative incidence of suboptimal therapy during a two-year follow-up period, defined by the presence of the following indicators: dose escalation, discontinuation, switching, non-biologic therapy escalation, or surgery.

RESULTS

The study included 1195 anti-TNF initiators (538 UC and 657 CD). The majority of patients (64% of UC and 58% of CD) had at least one indicator of suboptimal therapy. The median time to suboptimal therapy indicator was 12.5 and 17.5 months for UC and CD patients, respectively. Among the 111 UC and 174 CD anti-TNF switchers, 51% and 56% had an indicator of suboptimal therapy, respectively. The median time to suboptimal therapy indicator with the second anti-TNF was 14.3 and 13.0 months for UC and CD patients, respectively.

CONCLUSION

The majority of IBD patients showed suboptimal therapy with current anti-TNFs.

Pegloticase in gout treatment - safety issues, latest evidence and clinical considerations

Gout is a common rheumatic condition, with increasing prevalence in recent decades. The mainstay of treatment for gout is oral urate-lowering therapy (ULT), typically with xanthine oxidase inhibitors (XOIs). Unfortunately, a proportion of patients have persistent gout that is refractory to ULT. Pegloticase, a recombinant pegylated uricase, has been approved by the US Food and Drug Administration for the treatment of refractory gout. However, concern has been raised regarding the risk of infusion reactions, which are now understood to be largely due to the development of antipegloticase antibodies. Discontinuation of pegloticase upon failure to lower serum urate has been shown to markedly reduce infusion reaction risk, but deprives patients of what, in many cases, is a last-resort treatment. In this manuscript, we review the rationale, mechanism of action, efficacy and safety of pegloticase. Additionally, we focus on potential strategies to reduce pegloticase immunogenicity and potentially make this important agent available to a wider group of patients requiring treatment.

Clinical performance of an infliximab rapid quantification assay

BACKGROUND

Therapeutic drug monitoring (TDM)-based algorithms can be used to guide infliximab (IFX) adjustments in inflammatory bowel disease (IBD) patients. This study aimed to explore a rapid IFX-quantification test from a clinical perspective.

METHODS

This manuscript describes a prospective cohort study involving 110 ulcerative colitis (UC) patients on the maintenance phase of IFX. IFX trough levels were quantified using a rapid quantification assay and a commonly-used reference kit.

RESULTS

Irrespective of the assay used to measure IFX, its through levels were statistically different between patients with and without endoscopic remission (Mayo endoscopic score = 0), as well as between patients stratified by their faecal calprotectin (FC) levels. Despite the fact that the two methods correlated well with each other [Spearman's rank correlation coefficient = 0.843, p < 0.001; intraclass correlation coefficients = 0.857, 95% confidence interval (CI): 0.791-0.903], there was a discernible systematic variation; values obtained with the reference kit were on average 2.62 units higher than those obtained with the rapid assay. Notwithstanding, 3 µg/ml was shown to be an acceptable cut-off to assess endoscopic status and inflammatory burden levels using both assays. The percentage of patients that had a positive outcome when the IFX concentration measured by the rapid assay ranked above 3 µg/ml was 88% both for a Mayo endoscopic score ⩽ 1 and for an FC concentration <250 µg/g.

CONCLUSIONS

Based on this study, we concluded that using the rapid IFX assessment system with a 3 µg/ml threshold is a reliable alternative to the time-consuming enzyme-linked immunosorbent assays in patients on the maintenance phase of IFX.

Therapeutic drug monitoring of CT-P13: a comparison of four different immunoassays

BACKGROUND

The commercialization of CT-P13, an infliximab (IFX) biosimilar, has the potential to decrease health-related costs and enhance access to biological therapies. This study aimed to address the accuracy and inter-assay agreement of the CT-P13 quantification using four different assays initially developed to assess IFX.

METHODS

The four different methods, one in-house method and three commercially available kits, were used to quantify exogenously-spiked samples and the sera from 185 inflammatory bowel disease (IBD) patients on CT-P13 therapy.

RESULTS

The quantification of the spiked samples unveiled a consistent and accurate behaviour of three of the tested methods, with average percentage recoveries of 90%, 102% and 109%. Results from the clinical samples demonstrated that these three assays were also highly correlated, both concerning Spearman's rank coefficients (range 0.890-0.947) and intraclass correlation coefficients (range 0.907-0.935). There were a few systematic deviations among them, but their impact in the clinical stratification of the patients using different cut-offs was minimal, particularly when these cut-offs were in the 3-4 µg/ml range, for which the strength of agreement (as assessed by the Kappa statistics that ranged from 0.732 to 0.902) was substantial to almost perfect.

CONCLUSIONS

Our results indicate that three of the tested IFX quantification methods can be used to accurately quantify CT-P13 without any adjustments.

Systematic review with meta-analysis: loss of response and requirement of anti-TNFα dose intensification in Crohn's disease

BACKGROUND

To review the frequency with which anti-TNF-α loses its effect and dose "intensification" is required for Crohn's disease (CD) treatment.

METHODS

Electronic databases were searched for eligible studies. Raw data from studies meeting inclusion criteria were pooled for effect estimates. Subgroup analyses were performed for exploration of heterogeneity regarding all outcomes.

RESULTS

Eighty-six eligible studies were included. Estimates of loss of response (LOR) incidence ranged from 8 to 71%. The random effects pooled incidence of LOR with a median follow-up of 1-year was 33% (95% CI 29-38, 55 studies, n = 6135). The effect estimate based on data from patients with infliximab was 33% (95% CI 27-40), 30% (95% CI 22-39) for adalimumab, and 41% (95% CI 30-53) for certolizumabpegol. Overall, the mean percentage of patients' LOR to anti-TNFs was 38.5%. The annual risk for LOR was 20.9% per patient-year. The random-effects pooled rate of need for dose intensification with a median follow-up of 1 year was 34% (95% CI 28-41, 38 studies, n = 10,690). The effect estimate for infliximab was 38% (95% CI 28-50), 36% (95% CI 30-43) for adalimumab, and 2% (95% CI 2-3) for certolizumab-pegol. The mean percentage of patients who needed an anti-TNF dose escalation was 23% with an annual risk of 18.5% per patient-year. There was no evidence of publication bias for incidence of LOR but not for the dose intensification (p = 0.001).

CONCLUSIONS

Overall, around one-third of CD patients experience a LOR and required dose intensification in primary anti-TNF-α responders.

Indicators of suboptimal biologic therapy over time in patients with ulcerative colitis and Crohn's disease in the United States

This study assessed the occurrence of indicators for suboptimal biologic therapy among ulcerative colitis (UC) and Crohn’s disease (CD) patients over time in the United States (US). Data from a large US claims database (2005–2013) were used to retrospectively identify patients with diagnosed with either UC or CD who were new biologic users. Indicators of suboptimal biologic therapy included: dose escalation during the maintenance phase, discontinuation of the initial biologic, switch to another biologic within 90 days following the last day of supply of the initial biologic, augmentation with a non-biologic systemic therapy, UC- or CD-related surgery, UC- or CD-related urgent care, and development of fistula (for CD only). Kaplan-Meier analyses were used. A total of 1,699 UC and 4,569 CD patients were included. Among UC patients, 51.1% and 90.9% experienced ≥1 indicator of suboptimal biologic therapy within 6 months and 36 months of biologic therapy initiation, respectively. Among CD patients, 54.3% and 91.4% experienced ≥1 indicator of suboptimal biologic therapy within 6 and 36 months of biologic therapy initiation, respectively. For both UC and CD patients, the most frequent indicators of suboptimal biologic therapy were discontinuation, dose escalation and augmentation. In conclusion, this study found that the occurrence of suboptimal biologic therapy is common among patients with UC and CD, with approximately 90% of patients experiencing at least one indicator of suboptimal biologic therapy within 36 months of biologic treatment initiation.

The safety of vedolizumab for the treatment of ulcerative colitis

INTRODUCTION

Vedolizumab is a humanized monoclonal antibody to the α4β7-integrin that blocks lymphocyte trafficking to the gut and is approved for treatment of patients with moderate-to-severe ulcerative colitis (UC). The gut-selective mechanism of action has the potential to improve vedolizumab's safety profile compared to other approved biologic drugs. Areas covered: We review the mechanism of action, efficacy and safety of vedolizumab treatment for UC. The positioning of vedolizumab in management algorithms is also discussed. Expert opinion: The highly selective mechanism of action of vedolizumab restricts immunosuppressive effects to the gut. Vedolizumab is efficacious as induction and maintenance therapy in UC patients who are naïve or refractory to tumor necrosis factor antagonists. No clinically important safety signals have been identified. Infusion reactions are reported in <5% of cases. The rates of adverse events (AE), serious AEs, and serious infections were not different between patients treated with placebo and those who received vedolizumab in a pooled analysis of six randomized controlled trials. Rates of malignancy and mortality in vedolizumab-exposed patients are similar to those of the general UC patient population. Progressive multifocal leukoencephalopathy has not been observed. Vedolizumab is a safe and effective therapy for UC with a unique mechanism of action.

Inflammatory Bowel Diseases (Crohn´s Disease and Ulcerative Colitis): Cost of Treatment in Serbia and the Implications

BACKGROUND

Although the costs of treating inflammatory bowel disease (IBD) in developed countries are well established, they remain largely unknown in countries with recent histories of socio-economic transition including Serbia.

OBJECTIVE

To estimate the costs of treatment including the resources used by patients with IBD in Serbia from a societal perspective. This includes both Crohn's disease and ulcerative colitis.

METHODS

This cost-of-illness study was conducted to identify direct, indirect and out-of-pocket costs of treating patients with IBD in Serbia. Patients with IBD (n = 112) completed a semi-structured questionnaire with data concerning their utilisation of heath-care resources and illness-related expenditures. All costs were calculated in Republic of Serbia dinars (RSD) at a 1-year level (2014) and subsequently converted to Euros. Median values and ranges were reported to avoid potential distortions associated with mean costs.

RESULTS

Median total direct costs and total indirect costs per patient per year in patients with Crohn's disease were 192,614.32RSD (€1602.97) and 28,014.00RSD (€233.13) and 142,267.15RSD (€1183.97) and 21,436.00RSD (€178.39), respectively, in patients with ulcerative colitis. In both groups, the greatest component of direct costs was hospitalisation.

CONCLUSIONS

Costs of IBD in Serbia are lower than in more developed countries for two reasons. These include the fact that expensive biological therapy is currently under-utilised in Serbia and prices of health services are largely controlled by the State at a low level. The under-utilisation of biologicals may change with the advent of biosimilars at increasingly lower prices.

Therapeutic drug monitoring of anti-tumour necrosis factor-α agents in inflammatory bowel disease

INTRODUCTION

Anti-TNFα therapy has revolutionised treatment of inflammatory bowel disease, however primary non-response and secondary loss of response are a significant problem. Therapeutic drug monitoring (TDM) has recently emerged as a means of optimising use of anti-TNFα agents. Areas covered: TDM of anti-TNFα agents can guide clinical decisions during treatment failure events, prevent treatment failure events, and potentially result in significant healthcare cost saving. TDM for anti-TNFα agent involves measurement of drug levels and anti-drug antibodies, and can be performed reactively or proactively. Reactive TDM reserves testing for treatment failure events, while proactive TDM also consists of periodic TDM for patients responding to anti-TNFα therapy to allow treatment optimisation. Generation of anti-drug antibodies is recognised as one important mechanism of treatment failure and adverse events. Expert opinion: Evidence strongly supports TDM at time of treatment failure, while studies employing proactive TDM have demonstrated conflicting results. TDM can also help better select patients likely to remain in clinical remission on anti-TNFα treatment interruption. Currently TDM is used to optimise anti-TNFα treatment, but it is not used by most clinicians to prevent adverse reactions to anti-TNFα agents.

Proactive therapeutic drug monitoring of infliximab: a comparative study of a new point-of-care quantitative test with two established ELISA assays

BACKGROUND

Therapeutic drug monitoring is a powerful strategy known to improve the clinical outcomes and to optimise the healthcare resources in the treatment of autoimmune diseases. Currently, most of the methods commercially available for the quantification of infliximab (IFX) are ELISA-based, with a turnaround time of approximately 8 h, and delaying the target dosage adjustment to the following infusion.

AIM

To validate the first point-of-care IFX quantification device available in the market - the Quantum Blue Infliximab assay (Buhlmann, Schonenbuch, Switzerland) - by comparing it with two well-established methods.

METHODS

The three methods were used to assay the IFX concentration of spiked samples and of the serum of 299 inflammatory bowel diseases (IBD) patients undergoing IFX therapy.

RESULTS

The point-of-care assay had an average IFX recovery of 92%, being the most precise among the tested methods. The Intraclass Correlation Coefficients of the point-of-care IFX assay vs. the two ELISA-based established methods were 0.889 and 0.939. Moreover, the accuracy of the point-of-care IFX compared with each of the two reference methods was 77% and 83%, and the kappa statistics revealed a substantial agreement (0.648 and 0.738).

CONCLUSIONS

The Quantum Blue IFX assay can successfully replace the commonly used ELISA-based IFX quantification kits. This point-of-care IFX assay is able to deliver the results within 15 min makes it ideal for an immediate target concentration adjusted dosing. Moreover, it is a user-friendly desktop device that does not require specific laboratory facilities or highly specialised personnel.