Factors that influence infliximab biosimilar trough levels in the pediatric inflammatory bowel disease population

BACKGROUND

The pharmacokinetics and pharmacodynamics of biosimilar infliximab (IFX-BioS) in pediatric inflammatory bowel disease (IBD) are poorly investigated. The aim of this study was to investigate factors predicting IFX-BioS trough levels (TLs).

RESEARCH DESIGN AND METHODS

IBD children with an indication to start IFX-BioS were included in this prospective observational study (January 2021-June 2022). TLs were measured at the 4th and 6th infusions and correlated with several covariates.

RESULTS

A total of 110 TLs in 55 children were included. The multivariate linear regression model at the 4th infusion found a positive correlation between TLs and age at diagnosis (B:1.950, 95% CI: [0.019, 3.882], p = 0.048) and IFX-BioS dose/kg (B:1.962, 95% CI: [0.238, 3.687], p = 0.029), and a negative correlation with clinical scores (B:-0.401, 95% CI: [-0.738, -0.064], p = 0.023). At the 6th infusion, female gender (B:6.887, 95% CI: [0.861, 12.913], p = 0.029), hemoglobin (B:1.853, 95% CI: [0.501, 3.204], p = 0.011), and IFX-BioS dose/kg (B:1.792, 95% CI: [0.979, 2.605], p < 0.001) were found to be positively correlated to TLs. No association between combined clinical and biochemical remission and TLs was found.

CONCLUSIONS

This study discovered some predictors for IFX-BioS TLs in IBD children. Knowledge of predictive factors could help physicians choose the best dosing regimen.

Early infliximab trough levels in paediatric IBD patients predict sustained remission

Background

Exposure-response studies have shown that higher infliximab concentrations are associated with better outcomes in inflammatory bowel disease. There is little agreement about the optimal time to measure infliximab levels in children.

Objectives

We aimed to evaluate whether trough levels at week 6 or week 14 predict sustained remission. The secondary aim was to define target trough levels at weeks 6 and 14.

Design

We used routinely collected electronic healthcare data of 70 anti-tumour necrosis factor naïve children with inflammatory bowel disease treated with a standard infliximab induction- and variable maintenance scheme.

Methods

Trough levels and blood and faecal markers for disease activity were measured before every infliximab administration. Sustained remission was defined as the absence of symptoms and low inflammatory markers between weeks 26 and 52 after the start of infliximab therapy. Optimal infliximab levels at weeks 6 and 14 were determined using the receiver operating characteristic curve.

Results

The median infliximab level at week 6 was not significantly higher in children who achieved sustained remission compared to those who did not (16.9 mg/L versus 12.0 mg/L; p = 0.058) but the median infliximab level at week 14 was significantly higher in those with sustained remission (7.7 mg/L versus 3.8 mg/L; p = 0.006). The area under the receiver operating characteristics curves at weeks 6 and 14 to predict sustained remission was 0.67 (95% CI 0.51-0.83) and 0.75 (95% CI 0.60-0.90), respectively. Target trough levels at weeks 6 and 14 were ⩾13.2 and ⩾6.9 mg/L, respectively.

Conclusion

An infliximab measurement at week 14 with a target through level ⩾6.9 mg/L best predicted sustained remission.

Switching Vedolizumab from IV to SC Injection in Inflammatory Bowel Disease Patients with Active Disease: Real-World Experience from a German IBD Cohort

BACKGROUND

Vedolizumab (VDZ) for subcutaneous (SC) injection was approved for use in Europe in 2020 and the US in 2023. Promising efficacy and tolerability have been proven in pivotal trials. However, real-world data on the SC use of VDZ, especially in patients with active disease, are still lacking. We aimed to determine treatment persistence and the drug's efficacy in inflammatory bowel disease (IBD) patients with active disease in comparison to patients in clinical remission.

METHODS

Patients treated for IBD in a tertiary care center from July 2020 to December 2021 were included in this study. Clinical and biochemical parameters and data on treatment adherence were collected. VDZ trough levels and disease activity before and after the switch from intravenous (IV) to SC injections were monitored during routine checkups and were retrospectively analyzed. The patients were followed up until week 20.

RESULTS

Eighty-two patients were included in the study. Of them, 35 patients had active disease (35/82 = 43%) at the time of the switch and 47 patients (47/82 = 57%) were in remission. In total, 10 patients experienced switch failure, 5 were switched back to IV VDZ, and 5 were swapped to a different biologic agent. We observed an increase in VDZ trough levels from the switch to week 8 and from the switch to week 20 in the remission group. Vedolizumab trough levels of 7.4, 51.4, and 33.45 ug/mL at the switch, week 8, and week 20 were identified to discriminate between remission and disease activity in our cohort. There was no new safety signal detected during the study period.

CONCLUSIONS

The switch from IV to SC VDZ proved to be efficient, safe, and even capable of reducing residual disease activity.

Tacrolimus monitoring in hair samples of kidney transplant recipients

Background

Calcineurin inhibitors, including tacrolimus, remain a cornerstone of immunosuppressive therapy after kidney transplantation. However, the therapeutic window is narrow, and nephrotoxic side effects occur with overdose, while the risk of alloimmunization and graft rejection increases with underdose. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) allows quantification of tacrolimus in biological samples from patients. This study investigates the feasibility of quantifying tacrolimus in scalp hair from kidney transplant (KT) recipients and correlates hair tacrolimus concentrations with tacrolimus dosage and blood trough levels. The aim was to provide proof-of-principle for hair tacrolimus drug monitoring in KT recipients.

Method

Single-center prospective study between September 9, 2021 and December 4, 2021, including KT recipients under tacrolimus. Minors, patients with active skin or hair diseases, and patients with scalp hair shorter than 4 cm were excluded from participation. Scalp hair was collected from the posterior vertex of patients, cut into segments, and analyzed for tacrolimus by LC-MS/MS. Patients filled out a questionnaire on hair treatments and washing habits. In parallel, tacrolimus trough levels were measured in whole blood and correlated with hair tacrolimus concentrations.

Results

In total, 39 consenting KT recipients were included, and hair samples were collected at 53 visits. Tacrolimus was detected in 98% of hair samples from patients exposed to the drug. Tacrolimus hair levels and whole blood trough levels were correlated with a beta coefficient of 0.42 (95% CI: -0.22-1.1, p = n.s.). Age and dark hair affected hair tacrolimus measurements, while different tacrolimus formulations (immediate release vs. extended release), hair washes, and permanent coloring did not. Longitudinal measurements in a subgroup of patients indicate that long-term measurement of hair tacrolimus levels is feasible.

Conclusion

Measuring tacrolimus in hair is a potentially reliable method to monitor drug exposure in KT patients. Rapid wash-in effects and consistent concentrations over time indicate that tacrolimus is incorporated into the hair matrix, allowing temporal resolution in the analysis of recent exposure and exposure history. This method provides a simple and low-risk alternative to regular blood sampling, sparing patients from frequent hospital visits through the self-collection of hair samples.

The risk of COVID-19 in IBD patients is increased by urban living and is not influenced by disease activity or intravenous biologics

Background

Patients with inflammatory bowel disease (IBD) may have a modified immune response to SARS-CoV-2. The objectives were to evaluate the prevalence of COVID-19 in patients treated with infliximab or vedolizumab, to analyze the factors associated with the infection, the impact of treatments and trough levels.

Methods

Patients with IBD treated with intravenous biologics in 14 French centers were included between March and June 2020 and followed-up for 6 months. Blood samples were collected for serologies and trough levels. The analysis of factors associated with COVID-19 was conducted in a matched 1:1 case-control sub-study with positive patients.

Results

In total, 1026 patients were included (74.9% infliximab). Over the follow-up period, 420 patients reported the occurrence of COVID-19 symptoms; 342 had been tested of whom 18 were positive. At the end of follow-up, 38 patients had a positive serology. Considering both nasal tests and serologies together, 46 patients (4.5%) had been infected. The risk of COVID-19 was related neither to the use of treatments (whatever the trough levels) nor to disease activity. Infections were more frequent when using public transport or living in flats in urban areas.

Conclusions

The prevalence rate of COVID-19 in this IBD population treated with intravenous infliximab or vedolizumab was the same as the one in the French population before the start of the vaccination campaign. The risk was increased by urban living and was not influenced by disease activity or biologics. Sanitary barrier measures remain the best way to protect against SARS-CoV-2 in patients with IBD in biological therapy.

Infliximab trough levels are associated with endoscopic healing but not with transmural healing at one year treatment with infliximab in pediatric patients with Crohn's disease

Introduction

It is well known that infliximab (IFX) trough levels (TLs) are associated with endoscopic healing (EH) in Crohn's disease (CD). We investigated whether IFX TLs are associated with transmural healing (TH) in pediatric patients with CD following 1-year treatment.

Methods

Pediatric patients with CD treated with IFX were included in this single-center prospective study. IFX TL tests, magnetic resonance enterography (MRE), and colonoscopies were simultaneously conducted after 1-year IFX treatment. TH was defined as a wall thickness of ≤3 mm without inflammatory signs evaluated using MRE. EH was defined as a Simple Endoscopic Score for Crohn's disease of <3 points on colonoscopy.

Results

Fifty-six patients were included. EH and TH were observed in 60.7% (34/56) and 23.2% (13/56) of patients, respectively. IFX TLs were higher in patients with EH (median, 5.6 vs. 3.4 µg/mL, P = 0.002), whereas IFX TLs showed no significant difference in patients with and without TH (median, 5.4 vs. 4.7 µg/mL, P = 0.574). No significant difference was observed in EH and TH between patients whose intervals were shortened or not. Multivariate logistic regression analysis showed that IFX TLs and disease duration to IFX initiation were associated with EH (odds ratio [OR] = 1.82, P = 0.001, and OR = 0.43, P = 0.02, respectively).

Discussion

In pediatric patients with CD, IFX TLs were associated with EH but not with TH. Further studies investigating long-term TH and proactive dosing based on therapeutic drug monitoring may clarify whether an association between IFX TLs and TH exists.

Do Vedolizumab trough Levels Predict the Outcome of Subsequent Therapy in Inflammatory Bowel Disease?

Background: Vedolizumab trough serum levels have been associated with clinical and endoscopic response in patients with inflammatory bowel disease (IBD). A recent study demonstrated that higher trough levels before dose escalation are associated with favorable outcomes. Objectives: We aimed to identify whether vedolizumab trough levels predict outcome of subsequent therapy. Methods: This retrospective study included IBD patients consecutively receiving vedolizumab therapy between November 2014 and June 2021. Only patients with a loss of response (LOR) to vedolizumab and available trough drug levels prior to therapy cessation were included. Clinical and endoscopic scores were recorded at 6 and 12 months post switching therapy. Results: Overall, 86 IBD patients (51 Crohn's disease, 35 ulcerative colitis) who discontinued vedolizumab were included; of those, 72 (83.7%) were due to LOR. Upon vedolizumab discontinuation, 66.3% of patients were switched to another biologic therapy. Trough vedolizumab levels at discontinuation due to LOR did not differ between patients with clinical response and LOR regarding subsequent therapy at 6 months [median 33.8 μg/mL (IQR 13.2-51.6) versus 31.7 μg/mL (IQR 9.1-64.8), p = 0.9] and at 12 months [median 29.6 μg/mL (IQR 14.3-51.6) versus 34.1 μg/mL (IQR 12.2-64.7), p = 0.6]. Patients progressing to subsequent surgery had numerically lower vedolizumab trough levels at LOR compared with patients who were treated with an additional medical therapy (median 14.3, IQR 4-28.2 μg/mL versus 33.5, IQR 13-51.6 μg/mL, p = 0.08). Conclusions: Vedolizumab trough levels upon LOR do not predict response to subsequent medical therapy; however, lower drug levels may suggest a more aggressive disease pattern and future need for surgery.

Predictive value of infliximab trough levels in maintenance therapy for 5-year sustained clinical remission in patients with inflammatory bowel disease

BACKGROUND

Despite long-term use of infliximab (IFX) in IBD treatment, its optimized use is unclear due to its complicated pharmacokinetics/dynamics. Hence, the predictive value of IFX trough levels (TL) is important in treatment management.

METHODS

We performed a prospective, cross-sectional, observational study with 74 IBD patients treated with IFX (mean 9.1 years, SD ± 3). TL was measured during maintenance therapy, in which maintenance of remission was followed for 5 years.

RESULTS

 TL > 3 µg/ml during maintenance therapy was a significant predictor of clinical remission in 5 years in UC patients (82 % vs 62 %, p 3 µg/ml during maintenance therapy in a cohort of IBD patients (p = 0.05). Deviations in percentage of remission and fraction of relapses in TL categories were insignificant in a cohort of CD patients (85 % vs 74 %, p > 0.05).

CONCLUSIONS

 TL > 3 µg/ml during maintenance therapy is a strong predictor of sustained clinical remission for 5 years in UC patients. The use of combination therapy with AZA, due to its significant association with high TL, may have a practical benefit in achieving better clinical outcomes in UC patients (Tab. 2, Fig. 10, Ref. 20).

Free antibodies-to-infliximab are biomarker for predicting the effect of dose intensification in pediatric Crohn's disease patients with secondary loss of response

Background

Immunogenicity to antitumor necrosis factor alpha agents, such as infliximab (IFX), may lead to therapeutic failure.

Objectives

This study evaluated the relationship between free and total antibodies-to-infliximab (ATIs), trough levels (TLs) of IFX, and the response to dose intensification.

Design

We performed a prospective, observational study including pediatric patients with Crohn's disease (CD) receiving IFX maintenance therapy without dose intensification.

Methods

We compared clinical and laboratory outcomes according to the presence of free and total ATIs. Factors associated with response to IFX dose intensification were investigated by analyzing IFX TLs and free and total ATIs.

Results

Of the 98 patients, 9 patients had detectable free ATIs and 38 patients had total ATIs. Patients with free ATIs had significantly lower TLs (0.7 versus 5.1 µg/mL, p < 0.001) than patients without free ATIs. However, there was no difference in the IFX TLs according to the presence of total ATIs (p = 0.2523). Analysis of the 38 samples with total ATIs showed that response to dose intensification was significantly lower in patients with free ATIs than those without free ATIs (22.2% versus 65.5%, p < 0.001). In addition, free ATIs were the only factor with poor response to dose intensification [odds ratio (OR): 14.15, 95% confidence interval (CI): 1.31-151.97, p = 0.0140]. According to the receiver operating characteristic analysis, the optimal cutoff level indicating non-response to IFX dose intensification was 30.0 AU/mL for free ATIs concentration (area under curve, 0.792; 95% CI: 0.590-0.942; sensitivity, 60.0%; specificity, 96.7%; p = 0.0241).

Conclusion

Free ATIs, but not total ATIs, have a negative impact on the course of CD. Free ATIs are potential reliable biomarker for predicting the effect of dose intensification in patients with loss of response to IFX. Future studies based on serial and proactive therapeutic drug monitoring are required in the future.

A Novel Class of On-Treatment Cancer Immunotherapy Biomarker: Trough Levels of Antibody Therapeutics in Peripheral Blood

While immune checkpoint blockade has revolutionized cancer treatment, unfortunately most patients do not benefit from this treatment. Many pharmacodynamic (PD) studies have revealed essential requirements for successful cancer immunotherapy that may provide insight into how we can improve these agents. Despite enormous efforts focused on interrogating the immune system using different biospecimens (e.g. blood, primary tumor, metastatic tumor, microbiome samples), a variety of technologies (e.g. flow cytometry, bulk and single-cell RNA-sequencing, immunohistochemistry), and wide-ranging disciplines (e.g. pathology, genomics, bioinformatics, immunology, cancer biology, metabolomics, bacteriology), discovery of consistent biomarkers of response have remained elusive. Pharmacokinetics (PK) studies, however, not only provide critical information regarding safe dosing but may also reveal useful biomarkers. For example, recent studies found that trough levels of therapeutic monoclonal antibodies (mAbs) or clearance (CL) of them were associated with clinical outcome, which suggests that trough levels of mAbs may represent a new class of on-treatment cancer immunotherapy biomarker. In this review, we summarize the potential utility of trough levels of mAbs, the mechanism of varying PK, consideration for therapeutic drug monitoring, and assay attributes that will facilitate wider utilization of PK information in conjunction with PD assessments.

The Role of Physiotherapy in the New Treatment Landscape for Haemophilia

The physiotherapist plays an essential role for people with haemophilia, an inherited bleeding disease responsible for musculoskeletal complications. Yet, with the advent of new and advanced therapies, the medical landscape is changing, and physiotherapy must adapt alongside. This paper considers whether there will still be a need for physiotherapy in the era of advanced therapies, and discusses ways in which services should evolve to complement emerging treatment paradigms for haemostasis in people with haemophilia. Ultimately, physiotherapy will remain an important element of care, even for people with little joint damage and low risks in the era of the new mild phenotype. However, competencies will need to evolve, and physiotherapists in both primary care and specialist treatment centres should work with haematology colleagues to develop more sensitive tools for detecting early joint changes. Physiotherapists will also play a crucial role in counselling and physically coaching, monitoring the musculoskeletal status of people with haemophilia who have transitioned to new treatments.

STABIL-study: The Course of Therapy, Safety and Pharmacokinetic Parameters of Conversion of Prograf® to Tacrolimus HEXAL®/Crilomus® in Renal Transplant Recipients - an Observational Study in Germany

BACKGROUND/OBJECTIVE

Tacrolimus HEXAL®/Crilomus® is an approved generic immunosuppressant for the prevention and treatment of rejection following renal transplantation. For safe and socioeconomically efficient conversion from the innovator to generic formulation, high-quality data are necessary, in view of the different and country-specific comorbidities and pharmacokinetics in kidney transplant recipients.

PATIENTS AND METHODS

From 2014 to 2017, we enrolled 32 kidney transplant recipients, receiving newly prescribed Tacrolimus HEXAL®/Crilomus® in 5 German centers. Efficacy and safety data were collected over 6-8 months and retrospectively compared to the period prior to conversion.

RESULTS

The mean tacrolimus trough level was 4.91 ng/mL standard deviation (SD) (SD ±1.7) before and 5.06 ng/mL (SD ±1.97) after conversion. Mean tacrolimus trough concentration-dose-ratio (+/- SD) was 187.1 ng/mL/mg/kg/day (SD 99.2) for the reference and 205.1 ng/mL/mg/kg/day (SD 133) for the generic product, resulting in a non-significant difference of 18.0 ng/mL/mg/kg/day (SD 71.8) (p=0.84, Wilcoxon V=180). Overall, dosing had to be changed in 4 (14.8%) patients. Graft function remained stable and no rejections occurred.

CONCLUSION

In conclusion, conversion to the generic tacrolimus formulation can be considered safe and feasible in long-term kidney transplant recipients in Germany. As suggested by guidelines, a vigilant therapeutic drug monitoring is recommended to account for possible tacrolimus concentration variability on the individual patient level.

Redefining prophylaxis in the modern era

Prophylaxis is the globally accepted standard of care for persons with haemophilia and presents many advantages over episodic treatment. The prophylaxis benefits include bleed reduction, reduction in musculoskeletal complications and improvement in the quality of life. The currently evolving novel therapies for the management of haemophilia has ushered a new era characterized by improved prophylaxis targets and outcomes. These redefined targets and outcomes have necessitated the need to also redefine prophylaxis. In this state-of-the-art review, we redefine prophylaxis in the modern era by revisiting its definition, presenting data to support higher trough levels to achieve with prophylaxis and introducing steady-state haemostasis as a possible new target for prophylaxis.

Switching from IFX originator to biosimilar CT-P13 does not impact effectiveness,safety and immunogenicity in a large cohort of IBD patients

BACKGROUND

Switching from IFX originator to CT-P13 is safe; however, little data on immunogenicity exists.

RESEARCH DESIGN AND METHODS

Consecutive IBD patients on IFX originator were switched to CT-P13 and followed-up for 12 months. Clinical activity, infliximab trough levels (ITLs), anti-drug antibodies (ATIs), and adverse events were recorded at predefined timepoints (baseline, second CT-P13 infusion, 6 and 12 months). The outcomes investigated were immunogenicity, pharmacokinetics, effectiveness and safety.

RESULTS

119 patients were switched to CT-P13 after a median time with IFX of 5.8 years. No changes in mean ITLs were observed. ATIs were detected in 30 patients (25.2%): 14 before and 16 after switch. Mean persistent ATIs were significantly higher compared to mean transient ones (109.74 ng/mL ±84.70 vs 18.22 ng/mL ±11.37, p < 0.001), with significantly lower ITLs associated (mean 0.32 µg/mL ±0.6 vs 3.08 µg/mL ±3.22, p < 0.001). A significant decrease of patients in steroid-fee clinical remission was observed after the switch (p = 0.004), with subsequent improvement at 6 months (p = 0.005). Eighteen patients (15.1%) discontinued IFX, only 6 (5%) for loss of response.

CONCLUSIONS

Switching from infliximab originator to CT-P13 seems safe and effective, without differences in immunogenicity. A temporary reduction of clinical benefit after switching could be potentially explained by a 'nocebo-effect response'.

Lower vancomycin trough levels in adults undergoing unrelated cord blood transplantation

Vancomycin (VCM) is frequently used for neutropenic patients undergoing cord blood transplantation (CBT). We retrospectively examined the relationship between VCM trough levels and the efficacy and toxicity in 122 adult patients undergoing CBT in our institute. The median initial dose of VCM based on body weight was 9.1 mg/kg/dose (range, 6.0-22.6 mg/kg/dose). The median initial trough level of VCM for all patients was 4.50 µg/mL (range, 1.20-24.05 µg/mL), at a median of 3 days (range, 2-6 days) after VCM administration. The cumulative incidence of acute kidney injury (AKI) was 19% at 30 days after VCM administration. A higher median trough level of VCM during the first 7 days was significantly associated with the development of AKI in the multivariate analysis (Hazard ratio: 1.28, p = .026). These data suggest that a lower VCM trough level may be safe in adult patients undergoing CBT under therapy with nephrotoxic drugs.

Successful cyclosporin and ustekinumab combination therapy in a patient with severe steroid-refractory ulcerative colitis

The therapeutic management of patients with severe steroid-refractory ulcerative colitis still represents a critical clinical challenge. In this setting, cyclosporin is an effective and rapidly acting induction treatment that is applied in combination with maintenance therapeutic agents like thiopurines or vedolizumab. Here, we present the case of a 33-year-old ulcerative colitis patient with severe steroid-refractory ulcerative colitis who refused surgical intervention and previously demonstrated no long-term benefit to anti-TNF antibody, vedolizumab, cyclosporin, thiopurines or tofacitinib treatment. Intravenous cyclosporin therapy was re-initiated in the patient and, after signs of clinical response, therapy with ustekinumab was additionally applied. After 11 weeks of well tolerated cyclosporin and ustekinumab combination therapy, cyclosporin was discontinued upon clinical and endoscopic remission. Subsequently, ustekinumab treatment has been effective in maintaining remission during the follow-up period of 195 days.

Higher vedolizumab serum levels do not increase the risk of adverse events in patients with inflammatory bowel disease

Background: Although its mechanism of action may confer a safety benefit, vedolizumab has still been associated with adverse events (AE). We investigated whether inflammatory bowel disease (IBD) patients with higher trough vedolizumab serum levels experienced an increased risk of AEs.Methods: This was a retrospective study of 76 IBD patients with at least one measurement of serum vedolizumab available. Vedolizumab levels ranged from <3.5 mcg/mL to 87.2 mcg/mL (median = 15.8 mcg/mL). The primary outcome was the rate of overall AEs. Secondary outcomes included the rates of infections, dermatologic reactions, infusion reactions, and other AEs. Multivariate logistic regression analysis was performed to evaluate the relationship between serum vedolizumab levels and AEs.Results: 19 patients out of 76 reported AEs. In patients with higher vedolizumab levels, there were 10 AEs reported out of 38 patients, which was not significantly different from the 9 AEs reported in 38 patients with lower vedolizumab levels (26.3% vs. 23.7%, p = .79). After adjustment for potential covariates, IBD patients with higher vedolizumab levels did not have higher odds of an AE than patients with lower levels (OR 0.92, 95% CI 0.30-2.81). Longer duration of therapy had higher odds of AEs, (OR of 1.04 at 95% CI 1.00-1.09, p = .0494 per additional month). None of the other variables were associated with a greater risk of AEs.Conclusions: There does not appear to be an increased risk of adverse events in IBD patients with higher vedolizumab levels, but duration of therapy may increase the risk of AEs.

Identification of Target Golimumab Levels in Maintenance Therapy of Crohn's Disease and Ulcerative Colitis Associated With Mucosal Healing

INTRODUCTION

Golimumab is approved as a therapy for ulcerative colitis (UC) patients. Recent data also demonstrate efficacy in Crohn's disease (CD); however, little is known about target drug levels to achieve endoscopic remission.

METHODS

We performed a retrospective analysis of IBD patients on maintenance golimumab. Median trough levels were compared using Kruskal-Wallis test, and logistic regression was used to construct a probabilistic model to determine sensitivity and specificity of levels predicting mucosal healing.

RESULTS

Fifty-eight patients on maintenance golimumab were included (n = 39 CD, n = 19 UC/IBD-unclassified [IBDU]). Forty percent (n = 23) were cotreated with an immunomodulator, 95% (n = 55) of patients were anti-TNF experienced, and 15.5% (n = 9) had 3 or more prior biologic therapies. Forty-four percent of patients achieved mucosal healing with endoscopic response in a further 26% of patients. Clinical remission was recorded in 41% of patients, and 82% had clinical response. Patients were treated with doses generally higher than the approved maintenance dose. In CD patients, median golimumab trough levels were higher in patients with mucosal healing (8.8 μg/mL vs 5.08 μg/mL, P = 0.03). After calculation of a receiver operating characteristic (ROC) curve for mucosal healing vs nonresponse, a trough level >8 μg/mL was associated with mucosal healing, with 67% sensitivity, 88% specificity, and a likelihood ratio of 3:4.

CONCLUSION

Treatment with golimumab was associated with mucosal healing in 44% of all IBD patients. Higher golimumab levels were associated with mucosal healing in CD. These findings support the need for prospective studies to determine target golimumab levels in IBD, which may impact current clinical practices in relation to selection of maintenance dosing.

Infliximab and its biosimilar produced similar first-year therapy outcomes in patients with inflammatory bowel disease

AIM

Tumour necrosis factor α inhibitors (anti-TNFα) are the main therapy for moderate to severe inflammatory bowel disease (IBD) in children. Biosimilars to the original drug infliximab are now available, but there are few reports on their real-life use. We compared the outcomes of patients treated with infliximab and its biosimilar, CT-P13.

METHODS

We collected outcome data on anti-TNFα-naive patients who started infliximab in the Children's Hospital, University of Helsinki, Finland, in 2015-2016. We studied 51 paediatric patients with IBD at a median age of 12 (range 4-16): 65% had Crohn disease, 23 received the original infliximab drug and 28 received the biosimilar. During 2015, infliximab was introduced to all treatment-naïve patients, and during 2016, all treatment-naïve patients received the biosimilar.

RESULTS

We found no statistically significant differences between the two drug products related to the outcome of the therapy during the first year. There were no significant differences in the trough levels between the treatment groups. Likewise, the proportion of patients with therapy enhancement was comparable between the two treatment groups.

CONCLUSION

The first-year therapy outcomes of infliximab and its biosimilar were comparable. There were no alarming signs of differences in safety.

Post-induction infliximab trough levels and disease activity in the clinical evolution of pediatric ulcerative colitis

BACKGROUND AND AIMS

Recent adult evidence suggests that infliximab (IFX) trough levels (TL) in patients with severe ulcerative colitis (UC) may be decreased. The aims of our study were to compare post-induction IFX TL of children with severe versus moderate UC and to evaluate short- and long-term outcomes.

METHODS

In this single-center retrospective study, children with a diagnosis of UC starting IFX with a Pediatric Ulcerative Colitis Activity Index (PUCAI) ≥35 and with available post-induction TL were recruited. UC characteristics, IFX dosage and interval, primary non-response, IFX failure, and surgery after 24 months were collected. Post induction TL, anti-IFX antibodies, and laboratory evaluations at the time of starting IFX were also acquired.

RESULTS

A total of 90 children were enrolled, of whom 39 (43.3%) were classified as severe UC and 51 (56.6%) as moderate UC. Median post-induction IFX TL were lower in severe UC versus moderate group (5.5 vs 10.3; p = 0.03), despite a more frequently intensified IFX regimen. Children in the higher TL quartiles showed increased rates of clinical, biological, and combined remission (p = 0.04, p < 0.001, and p = 0.01, respectively). In a multivariate analysis, a PUCAI ≥65 and time interval from last IFX infusion were the only predictors associated with IFX TL. At 24 months, children in the higher TL quartiles had a decreased risk of IFX failure (p = 0.002). The severe UC group showed a higher risk of IFX failure at 24 months (16/23 (41%) vs. 11/40 (21.6%); p = 0.05). Kaplan-Meier methods demonstrated a trend toward statistical significance, with a two-year cumulative colectomy rate of 15.38% (95% confidence interval (CI) 8.1-15.6%) in children with severe UC and 3.92% (95% CI 2.9-10.8%) in patients with moderate UC (logrank test p = 0.06).

CONCLUSIONS

Children starting IFX with severe UC showed lower post-induction TL and poor disease outcomes. Achieving adequate TL was associated with better efficacy outcomes.

Evaluating Efficacy, Safety, and Pharmacokinetics After Switching From Infliximab Originator to Biosimilar CT-P13: Experience From a Large Tertiary Referral Center

BACKGROUND

The use of infliximab biosimilar CT-P13 has increased in patients with inflammatory bowel disease. Nevertheless, doubts about switching from infliximab originator to biosimilar still exist among patients and health care professionals.

METHODS

Our tertiary referral center underwent a mandatory switch from infliximab originator to CT-P13 in 2017. We investigated pharmacokinetics, efficacy, and safety of this switch. The primary endpoint was infliximab discontinuation within 6 months of switching. Secondary endpoints included loss of clinical remission, need for treatment optimization, adverse events, evolution of patient-reported outcome, C-reactive protein, infliximab trough levels, and antidrug-antibodies.

RESULTS

A total of 361 patients (54.0% male, 70.0% Crohn's disease, 55.6% in clinical remission) were enrolled. Infliximab discontinuation within 6 months was observed in 4%. Loss of clinical remission, adverse events, and antidrug-antibodies were identified in only 2.0%, 2.2%, and 1.1% of patients, respectively. C-reactive protein concentrations and infliximab trough levels remained stable. Independent factors associated with remission at 6 months were lower PRO2 at switch (HR 6.024; 95% CI, 4.878-8.000; P < 0.0001) and higher hemoglobin levels (HR 1.383; 95% CI, 1.044-2.299; P = 0.018).

CONCLUSIONS

Switching from infliximab originator to CT-P13 was not associated with an increased risk of treatment discontinuation, loss of clinical remission, or adverse events. No significant changes in infliximab trough levels or immunogenicity could be identified.

Attention to age: similar dosing regimens lead to different vancomycin levels among older and younger patients

BACKGROUND

little is known on the clinical implications of vancomycin trough levels among older patients.

OBJECTIVE

to evaluate the association between vancomycin levels and outcomes among older versus younger patients.

DESIGN

retrospective study.

SUBJECTS

patients aged 18-64 and ≥65 years treated with vancomycin for documented methicillin resistant Staphylococcus aureus (MRSA) infections.

METHODS

we compared the effectiveness and toxicity of vancomycin according to trough levels in older versus younger patients. Subgroup analysis of patients with glomerular filtration rate (GFR) > 60 ml/min/1.73 m2 was performed.

RESULTS

we included 181 patients aged ≥65 years and 104 younger patients. Mean age in the older group was 76.9 ± 8 years versus 50.9 ± 12.4 in the younger group. Vancomycin trough levels and 24-hours area under the curve to minimal inhibitory concentrations (AUC/MIC) were significantly higher in older patients who were also significantly more likely to achieve trough levels of ≥15 mg/l within 4 days, (98/181 (54.1%) vs. 38/104 (36.5%) in younger patients, P = 0.004). Results were similar among patients with GFR > 60. Thirty-day mortality was significantly higher in older (74/181, 40.9% vs. 13/104, 12.5%, respectively, P < 0.001). There was no association between vancomycin trough levels and mortality among older patients. No significant differences were demonstrated in clinical or microbiological success or nephrotoxicity.

CONCLUSIONS

applying uniform dosing recommendations across age groups among adults with MRSA infections results in higher vancomycin levels and AUC/MIC in older versus younger patients. Yet, mortality rates remain higher among older adults. Prospective studies are needed to define the optimal approach for using this drug in older patients.

Low Golimumab Trough Levels at Week 6 Are Associated With Poor Clinical, Endoscopic and Histological Outcomes in Ulcerative Colitis Patients: Pharmacokinetic and Pharmacodynamic Sub-analysis of the Evolution Study

BACKGROUND AND AIMS

Golimumab has an established exposure-response relationship in patients with ulcerative colitis [UC]. However, the association of serum golimumab trough levels [TL] with objective markers of disease activity, such as endoscopic and histological activity scores and concentrations of biomarkers, remains less understood. This report describes the relationship of serum golimumab TL at the end of the induction period [Week 6] with clinical, endoscopic, histological, and biomarker parameters.

METHODS

This was an open-label, uncontrolled, prospective and interventional study. Moderate to severely active UC patients naïve to biologic therapy were treated with golimumab. Serum golimumab TL and faecal calprotectin levels were measured at baseline [Week 0 of induction] and Week 6.

RESULTS

A total of 34 patients completed the induction phase [Week 6] and were included in this analysis. Overall, 47.1% and 14.7% of patients achieved clinical response and remission with significantly higher serum golimumab TL in patients with early response or remission [3.7 μg/mL vs 1.3 μg/mL, p = 0.0013; and 3.1 μg/mL vs 1.7 μg/mL, p = 0.0164, respectively]. In addition, golimumab TL were significantly higher in patients achieving histological remission [4.2 μg/mL vs 1.7 μg/mL, p = 0.0049]. Week 6 golimumab TL were inversely correlated with the total Mayo score [rs = -0.546; p = 0.0008], the Mayo endoscopic subscore [rs = -0.381; p = 0.0262], the Geboes histological activity score [rs = -0.464; p = 0.0057], and faecal calprotectin levels [rs = -0.497; p = 0.0044].

CONCLUSIONS

A higher early exposure to golimumab is associated with a better objective response in active UC patients and appears to drive the outcome at Week 6.

Dosing interval and diagnosis predict infliximab levels in patients with inflammatory bowel disease on maintenance treatment

OBJECTIVE

The aim of the study was to identify factors influencing infliximab (IFX) trough levels (TL) in patients with inflammatory bowel disease (IBD).

METHODS

This was a multicentre cross-sectional study performed at 5 large IBD centres in Slovakia. The cohort consisted of IBD patients, treated either with original IFX or CT-P13 biosimilar, who were examined for the IFX TL and antidrug antibodies (ADA) in a central laboratory.

RESULTS

The patient cohort consisted of 116 consecutive IBD patients, 68 with Crohn's disease (CD) and 48 with ulcerative colitis (UC). CD patients had significantly lower IFX TL compared to UC, 2.41 (0.998-5.56) mg/L vs. 4.49 (1.76-8.41) mg/L, p = 0.017. During maintenance treatment, significantly higher mean IFX TL were observed in patients with a 4 week dosing interval than in patients with a 6 or 8 (7.44±3.6 μg/mL vs. 4.19±4.2 vs. 3.30±3.1 μg/mL, p = 0.011 and p< 0.0001, respectively). There was no difference in median TL IFX between original IFX and biosimilar CT-P13 (3.25 (1.24-6.52) mg/L vs. 3.03 (1.30-7.10)). IFX TL correlated with ADA (p=0.005). Multiple regression analysis revealed two independent factors for IFX TL: dosing interval (p<0.0001) and diagnosis (p=0.02).

CONCLUSION

In the present study we observed that IBD patients assigned to an intensified dosing interval during maintenance therapy have significantly higher IFX TL than patients receiving conventional 8 week interval. Patients with UC had significantly higher IFX TL.

Reliability evaluation of four different assays for therapeutic drug monitoring of infliximab levels

BACKGROUND

The aim of this study was to evaluate reliability of four different assays for measuring infliximab trough levels and antibodies to infliximab (ATI).

METHODS

In this non-interventional, cross-sectional study including IBD patients, infliximab levels and ATI were measured using four different assays: Lisa-Tracker, Promonitor, Q-Inflixi and Sanquin. Reliability and agreement for infliximab levels was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman plots. Qualitative agreement for infliximab (based on a pre-established target window of trough levels between 3 µg/ml and 7 µg/ml) and for ATI were estimated by Cohen's kappa.

RESULTS

Serum samples of 84 IBD patients were evaluated for infliximab using the four assays. Reliability was 'substantial' between Lisa-Tracker versus Promonitor and 'almost perfect' between the remaining assay pairs, with ICCs [95% confidence interval (CI)] ranging from 0.93 (0.70-0.97) for Lisa-Tracker versus Promonitor to 0.97 (0.95-0.98) for Q-Inflixi versus Sanquin. Bland-Altman plots showed significant bias between assays except Promonitor versus Q-Inflixi, which had excellent agreement. The greatest differences in mean infliximab were found between Promonitor versus Lisa-Tracker (-0.91 µg/ml) and Lisa-Tracker versus Q-Inflixi (0.69 µg/ml). Qualitative agreement for infliximab was 'almost perfect' for Promonitor versus Q-Inflixi (kappa 0.84) and Q-Inflixi versus Sanquin (kappa 0.81), and 'substantial' for the remaining pairs. More than 10% of patients who had infliximab levels within the target interval by Lisa-Tracker had suboptimal concentrations (<3 µg/ml) with Promonitor and Q-Inflixi. Furthermore, 11% of patients within the target interval by Q-Inflixi had supra-optimal levels (>7 µg/ml) by Lisa-Tracker. In the remaining paired comparisons, fewer than 5% of patients were placed in different subgroups. Qualitative agreement for ATI fluctuated between 'moderate' and 'almost perfect'.

CONCLUSIONS

All four assays seem suitable for therapeutic drug monitoring of infliximab. Promonitor and Q-Inflixi had the best agreement, making those assays fully interchangeable. Systematic biases between Lisa-Tracker with Promonitor and Q-Inflixi suggest that these assays should not be interchanged during the follow up of an individual patient.

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.

Serum-Infliximab Trough Levels in 45 Children with Inflammatory Bowel Disease on Maintenance Treatment

The role of trough serum infliximab (s-IFX) and antibodies toward IFX (ATI) during maintenance treatment remains unclear in children. The aim of the present study was to investigate trough s-IFX and ATI to identify any correlation with inflammatory activity and clinical response in a pediatric inflammatory bowel disease (IBD) cohort. We investigated the s-IFX trough levels in pediatric IBD patients (n = 45) on maintenance IFX treatment. Ninety-three blood samples were collected and demographics, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and albumin were recorded. The mean s-IFX trough level was 5.2 µg/mL. The mean trough s-IFX level was significantly higher in the samples taken during remission (7.2 µg/mL) compared to active disease (4.5 µg/mL, p < 0.05). The trough s-IFX levels correlated with ESR, CRP, and albumin. S-IFX was undetectable in eight of the patients, all with positive ATI and active disease. Surprisingly, clinical and biochemical remission was observed at only 26 of the 93 visits. The correlation between dose variations and changes in trough s-IFX was not evident. In line with studies in adults, the s-IFX trough levels correlated with response to infliximab.

Golimumab pharmacokinetics in ulcerative colitis: a literature review

Golimumab (GLM) is the latest anti-tumor necrosis factor (TNF) that gained its marketing license. Thanks to the PURSUIT induction and maintenance trials, it was approved for the treatment of ulcerative colitis (UC) in 2013. The other anti-TNF drugs available are infliximab and adalimumab. These two drugs have validated algorithms concerning prescription and therapeutic drug monitoring (TDM) but little is known about GLM. The available data on GLM's exposure-response relationship in UC are from the PURSUIT trials and are recently published. The data reveal all the factors that may impact the pharmacokinetic (PK) parameters: dosage, body weight (BW), concomitant drugs, the presence of anti-drug antibodies (ADAbs), sex and age. In addition, the GLM trough level at steady-state appears to be correlated with the patient's improvement which may make it a precious indicator to predict the clinical response. There is, however, no consensus on a possible therapeutic level or cutoff associated with clinical response, remission, or any other outcome measure such as endoscopic healing in UC. This lack of a threshold value, and its validation with different assay techniques, makes it difficult to use GLM TDM in clinical practice. As with other anti-TNF agents, GLM is associated with development of ADAbs, of which the prevalence and effects are still insufficiently described. The objective of this review is to describe current data and understanding of the PK of GLM including serum concentrations of GLM and ADAbs in UC patients. Better understanding of these parameters could lead to improved patient care with GLM.

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

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

Serum Concentration of Anti-TNF Antibodies, Adverse Effects and Quality of Life in Patients with Inflammatory Bowel Disease in Remission on Maintenance Treatment

BACKGROUND AND AIMS

High serum concentrations of infliximab [IFX] and adalimumab [ADA] may be associated with adverse effects in patients with inflammatory bowel disease [IBD]. We aimed to investigate whether high anti-tumour necrosis factor [TNF] trough levels [TLs] were associated with toxicity and impaired quality of life [QoL].

METHODS

We conducted a prospective cohort study in IBD patients in clinical and biochemical remission on IFX or ADA maintenance therapy. Trough serum concentrations and antidrug antibodies were measured in addition to biochemical markers of inflammation in serum and stool to confirm quiescent disease. QoL was assessed using the Inflammatory Bowel Disease Questionnaire and 36-item short form]. Side effects such as fatigue and arthralgia were measured with a visual analogue score [VAS]. Skin toxicity was reported with a European Organization for Research and Treatment of Cancer-derived score.

RESULTS

In all, 252 IBD patients on maintenance anti-TNF therapy were screened, of whom 95 [73 with Crohn's disease, 22 with ulcerative colitis; 72 on IFX, 23 on ADA] were in clinical and biochemical remission and were included. Median TLs were 5.5 µg/ml and 6.6 µg/ml for IFX and ADA, respectively. Patients with anti-TNF TLs above median had lower IBDQ scores than patients with lower TLs [IBDQ 176 vs 187, p = 0.02], particularly regarding systemic symptoms and emotional status. A trend towards lower SF-36 and higher fatigue scores was observed in the higher anti-TNF TL group. Skin and arthralgia scores were not significantly different between the groups.

CONCLUSIONS

IBD patients with higher anti-TNF serum concentrations had significantly lower disease-specific QoL. Fatigue, arthralgia, and skin lesions do not occur more often in these patients. These data are reassuring that high serum concentrations of anti-TNF antibodies are not toxic.

Achieving therapeutic vancomycin levels in pediatric patients

BACKGROUND

Vancomycin is widely used to treat infections caused by methicillin-resistant Staphylococcus aureus. Data for dosing and monitoring of this drug in pediatric patients are lacking, and clinicians who are treating children often follow guidelines established for adults.

OBJECTIVES

To examine the total daily doses of vancomycin required to reach therapeutic trough levels (i.e., 10-20 mg/L) in infants, children, and adolescents, and to assess the number of pediatric patients in whom therapeutic trough levels are achieved with current empiric doses (40-60 mg/kg daily).

METHODS

This chart review evaluated patients 1 month to 18 years of age for whom vancomycin was prescribed at a single institution between November 2011 and October 2012. Patients' demographic characteristics, vancomycin dosing parameters, and subsequent steady-state trough concentrations were analyzed.

RESULTS

Overall, the proportion of patients who reached therapeutic trough levels with current empiric doses was 39% (74 of 188). The mean total daily dose (± standard deviation) required to achieve therapeutic trough levels was 57.8 ± 11.5 mg/kg for patients 1 to 5 months of age, 68.9 ± 15.4 mg/kg for those 6 to 23 months of age, 65.8 ± 13.0 mg/kg for those 2 to 12 years of age, and 55.7 ± 11.8 mg/kg for those 13 to 18 years of age.

CONCLUSIONS

Common empiric vancomycin dosing regimens (40-60 mg/kg daily) are not high enough to achieve trough levels of 10-20 mg/L in the majority of pediatric patients. Given these data, the authors suggest a starting dose of 60 mg/kg daily for patients 1 to 5 months of age and those 13 to 18 years of age and a starting dose of 70 mg/kg daily for patients 6 months to 12 years of age.

Tacrolimus trough levels after month 3 as a predictor of acute rejection following kidney transplantation: a lesson learned from DeKAF Genomics

Most calcineurin inhibitor (CNI)-based protocols reduce blood trough goals approximately 2-3 months post-transplant in clinically stable kidney transplant recipients. The CNI target trough level to prevent rejection, after reduction, is unknown. Using a multivariate Cox proportional hazards model, we determined the association of time-varying tacrolimus (TAC) trough levels with acute rejection (AR) occurring in the first 6 months post-transplant, but specifically we assessed this association after 3 months. A total of 1930 patients received TAC-based immunosuppression prior to AR in a prospective study. Of the 151 (7.8%) who developed AR, 47 developed AR after 3 months post-transplant. In an adjusted time-varying multivariate model, each 1 ng/ml decrease in TAC trough levels was associated with a 7.2% increased risk of AR [hazards ratio (HR) = 1.07, 95% confidence interval (CI) (1.01, 1.14) P = 0.03] in the first 6 months. There was an additional 23% increased risk of AR with each 1 ng/ml decrease in the TAC trough levels in months 3-6 [HR = 1.23, 95% CI (1.06, 1.43) P = 0.008]. In conclusion, lower TAC trough levels were significantly associated with increased risk of AR in the first 6 months post-transplant with additional risk of AR between months 3 and 6 post-transplant. The timing and practice of TAC dose reduction should be personalized based on the individual's risk factors.