Mirikizumab Exposure-Response Relationships in Patients with Moderately-to-Severely Active Ulcerative Colitis in Randomized Phase II and III Studies.

Mirikizumab is a humanized anti-interleukin-23p19 monoclonal antibody being developed for ulcerative colitis (UC) and Crohn's disease. We characterized the relationship of mirikizumab systemic exposure with efficacy and safety end points in patients with UC using phase II (NCT02589665) and III (NCT03518086, NCT03524092) trial data. Exposure-response models were developed for clinical remission, clinical response, endoscopic remission, and change in modified Mayo score following induction (50-1,000 mg i.v. every 4 weeks) and maintenance (200 mg s.c. every 4 or 12 weeks) treatment. These models evaluated observed and pharmacokinetic model-predicted mirikizumab exposures as the exposure measure. Key safety event rates were compared across mirikizumab exposure quartiles in the phase III trial. Mirikizumab efficacy in patients with UC showed an apparent positive association with systemic exposure following both induction and maintenance. However, further analysis found this relationship to be overstated by the presence of confounding factors that were not among the tested patient covariates. While prior biologic experience and baseline disease severity showed statistically significant influences on estimated placebo effect, no patient factors affected the mirikizumab effect parameters in any of the phase III exposure-response models. There was no apparent mirikizumab concentration relationship with any adverse event of special interest. When the phase II and III data and confounding are considered together, efficacy was unlikely to be strongly affected by variation in exposures across individual patients at the phase III dose. Together with the previously demonstrated mirikizumab exposure insensitivity to patient factors, these findings indicate that mirikizumab dose adjustment to patient characteristics is not required.

Pharmacogenetics in IBS: update and impact of GWAS studies in drug targets and metabolism.

INTRODUCTION: Medications are frequently prescribed for patients with irritable bowel syndrome (IBS) or disorders of gut brain interaction. The level of drug metabolism and modifications in drug targets determine medication efficacy to modify motor or sensory function as well as patient response outcomes. AREAS COVERED: The literature search included PubMed searches with the terms: pharmacokinetics, pharmacogenomics, epigenetics, clinical trials, irritable bowel syndrome, disorders of gut brain interaction, and genome-wide association studies. The main topics covered in relation to irritable bowel syndrome were precision medicine, pharmacogenomics related to drug metabolism, pharmacogenomics related to mechanistic targets, and epigenetics. EXPERT OPINION: Pharmacogenomics impacting drug metabolism [CYP 2D6 (cytochrome P450 2D6) or 2C19 (cytochrome P450 2C19)] is the most practical approach to precision medicine in the treatment of IBS. Although there are proof of concept studies that have documented the importance of genetic modification of transmitters or receptors in altering responses to medications in IBS, these principles have rarely been applied in patient response outcomes. Genome-wide association (GWAS) studies have now documented the association of symptoms with genetic variation but not the evaluation of treatment responses. Considerably more research, particularly focused on patient response outcomes and epigenetics, is essential to impact this field in clinical medicine.

Forecasted infliximab concentrations during induction predict time to remission and sustained disease control of inflammatory bowel disease.

BACKGROUND: Infliximab (IFX) exposure is established as a predictive factor of pharmacokinetic (PK) origin in inflammatory bowel disease (IBD), and expert consensus is to achieve adequate exposure during induction to achieve and sustain remission. METHODS: We retrospectively evaluated the performance of a Bayesian PK tool in IBD patients starting IFX. Trough IFX serum levels collected immediately before the third (at week 6) and fourth (at week 14) infusions were evaluated from 307 IBD patients (median age=17 years, 50 % females, 83 % with Crohn's disease). Forecasted IFX concentration at the fourth infusion were estimated using serum IFX, antibodies to IFX, albumin and weight determined immediately before the third infusion using population PK calculator with Bayesian prior. The outcome variable was a clinical & biochemical remission status achieved (CRP levels below 3 mg/L in presence of clinical remission). Statistics consisted of Kaplan Meier analysis with calculation of Hazard ratio (HR), and logistic regression. RESULTS: IFX concentration above 15 µg/mL immediately before the third infusion associated with shorter time to clinical & biochemical remission than concentration below 15 µg/mL without reaching significance (163±14 days vs 200±16 days, respectively; p=0.052). However, using PK parameters at the third infusion, forecasted IFX concentrations above 10 µg/mL immediately before the fourth infusion were significantly associated with a higher rate (HR=1.6 95 %CI: 1.1 to 2.1 p<0.01) and shorter time to remission (148±18 days vs 200±13 days p<0.01). In the presence of IFX concentration above 15 µg/mL at the third infusion, there was a significant 2.5-fold higher likelihood of sustained clinical & biochemical remission status during maintenance as compared to IFX concentrations below 15 µg/mL (p<0.01). Forecasted IFX level above 10 µg/mL at fourth infusion associated with significantly 3.9-fold higher likelihood of clinical & biochemical remission as compared to forecasted IFX concentrations below 10 µg/mL (p<0.01). CONCLUSIONS: These data further support that optimized IFX concentrations during induction are associated with enhanced disease control in IBD.

Fluorescently labelled vedolizumab to visualise drug distribution and mucosal target cells in inflammatory bowel disease.

OBJECTIVE: Improving patient selection and development of biological therapies such as vedolizumab in IBD requires a thorough understanding of the mechanism of action and target binding, thereby providing individualised treatment strategies. We aimed to visualise the macroscopic and microscopic distribution of intravenous injected fluorescently labelled vedolizumab, vedo-800CW, and identify its target cells using fluorescence molecular imaging (FMI). DESIGN: Forty three FMI procedures were performed, which consisted of macroscopic in vivo assessment during endoscopy, followed by macroscopic and microscopic ex vivo imaging. In phase A, patients received an intravenous dose of 4.5 mg, 15 mg vedo-800CW or no tracer prior to endoscopy. In phase B, patients received 15 mg vedo-800CW preceded by an unlabelled (sub)therapeutic dose of vedolizumab. RESULTS: FMI quantification showed a dose-dependent increase in vedo-800CW fluorescence intensity in inflamed tissues, with 15 mg (153.7 au (132.3-163.7)) as the most suitable tracer dose compared with 4.5 mg (55.3 au (33.6-78.2)) (p=0.0002). Moreover, the fluorescence signal decreased by 61% when vedo-800CW was administered after a therapeutic dose of unlabelled vedolizumab, suggesting target saturation in the inflamed tissue. Fluorescence microscopy and immunostaining showed that vedolizumab penetrated the inflamed mucosa and was associated with several immune cell types, most prominently with plasma cells. CONCLUSION: These results indicate the potential of FMI to determine the local distribution of drugs in the inflamed target tissue and identify drug target cells, providing new insights into targeted agents for their use in IBD. TRIAL REGISTRATION NUMBER: NCT04112212.

Pharmacokinetic considerations for drugs that treat diarrhea-predominant irritable bowel syndrome: what's new?

INTRODUCTION: Irritable bowel syndrome (IBS), which presents a significant healthcare and socioeconomic burden, is one of the main issues in the field of therapy. Hence, it is imperative to tackle this matter by evaluating the safety and efficacy of the available treatments and determining the ideal approach for each patient. AREAS COVERED: We reviewed the pharmacokinetics and safety of pharmacologic interventions administered in diarrhea-predominant IBS (IBS-D) patients. PubMed, Google Scholar and the USFDA databases were searched up to November 2023 to include all updated information on eluxadoline, alosetron, and rifaximin. EXPERT OPINION: The most effective way to treat IBS-D is to focus on managing the most common symptoms. However, healthcare providers face a challenge when it comes to identifying the right treatment for each patient, and the root cause of this is the diversity of IBS-D population. Studies have shown that there are differences in how men and women metabolize drugs, which may lead to gender-specific adverse reactions. Women tend to have higher drug concentrations in their bloodstream and take longer to eliminate them. Therefore, healthcare providers may need to reduce the dosage for female patients. Integrating IBS care into sustainable development efforts can indirectly contribute to achieving SDGs and promote health and well-being for all.

Best Practice for Therapeutic Drug Monitoring of Infliximab: Position Statement from the International Association of Therapeutic Drug Monitoring and Clinical Toxicology.

BACKGROUND: Infliximab, an anti-tumor necrosis factor monoclonal antibody, has revolutionized the pharmacological management of immune-mediated inflammatory diseases (IMIDs). This position statement critically reviews and examines existing data on therapeutic drug monitoring (TDM) of infliximab in patients with IMIDs. It provides a practical guide on implementing TDM in current clinical practices and outlines priority areas for future research. METHODS: The endorsing TDM of Biologics and Pharmacometrics Committees of the International Association of TDM and Clinical Toxicology collaborated to create this position statement. RESULTS: Accumulating data support the evidence for TDM of infliximab in the treatment of inflammatory bowel diseases, with limited investigation in other IMIDs. A universal approach to TDM may not fully realize the benefits of improving therapeutic outcomes. Patients at risk for increased infliximab clearance, particularly with a proactive strategy, stand to gain the most from TDM. Personalized exposure targets based on therapeutic goals, patient phenotype, and infliximab administration route are recommended. Rapid assays and home sampling strategies offer flexibility for point-of-care TDM. Ongoing studies on model-informed precision dosing in inflammatory bowel disease will help assess the additional value of precision dosing software tools. Patient education and empowerment, and electronic health record-integrated TDM solutions will facilitate routine TDM implementation. Although optimization of therapeutic effectiveness is a primary focus, the cost-reducing potential of TDM also merits consideration. CONCLUSIONS: Successful implementation of TDM for infliximab necessitates interdisciplinary collaboration among clinicians, hospital pharmacists, and (quantitative) clinical pharmacologists to ensure an efficient research trajectory.

Combination Therapy With Guselkumab and Golimumab in Patients With Moderately to Severely Active Ulcerative Colitis: Pharmacokinetics, Immunogenicity and Drug-Drug Interactions.

A proof-of-concept study with the combination of guselkumab and golimumab in patients with ulcerative colitis (UC) has shown that the combination therapy resulted in greater efficacy than the individual monotherapies. The current analysis evaluated the pharmacokinetics (PK) and immunogenicity of guselkumab and golimumab in both the combination therapy and individual monotherapies. Blood samples were collected to evaluate serum concentrations and immunogenicity of guselkumab and golimumab. Population PK (PopPK) models were developed to assess the effects of combination therapy and other potential covariates on the PK of guselkumab and golimumab. The guselkumab PK was comparable between monotherapy and combination therapy, whereas golimumab concentrations were slightly higher with combination therapy. The anti-guselkumab antibody incidence was low with both monotherapy and combination therapy, and guselkumab immunogenicity did not impact the clearance. Conversely, the anti-golimumab antibody incidence with combination therapy was lower than that for monotherapy. PopPK analysis suggested that the slightly higher golimumab concentrations with combination therapy were partially due to lower immunogenicity and thus lower clearance with combination therapy. C-reactive protein (CRP) was also a significant covariate on golimumab clearance. The greater improvement of inflammation with combination therapy, as shown by reductions in CRP, may have also contributed to the higher golimumab concentrations. Combination therapy slightly decreased the clearance of golimumab, but not guselkumab clearance, in patients with UC. Lower immunogenicity and greater improvement of inflammation with combination therapy were potential mechanisms for slightly increased golimumab concentrations with combination therapy as compared with golimumab monotherapy.

The Effect of Polymorphisms and Other Biomarkers on Infliximab Exposure in Paediatric Inflammatory Bowel Disease: Development of a Population Pharmacokinetic Model.

BACKGROUND: Therapeutic drug monitoring (TDM) of infliximab has been shown to be a effective strategy for inflammatory bowel disease (IBD). Population pharmacokinetic (PopPK) modeling can predict trough concentrations for individualized dosing. OBJECTIVE: The aim of this study was to develop a PopPK model of infliximab in a paediatric population with IBD, assessing the effect of single nucleotide polymorphisms (SNPs) and other biomarkers on infliximab clearance. METHODS: This observational and ambispective single-centre study was conducted in paediatric patients with IBD treated with infliximab between July 2016 and July 2022 in the Paediatric Gastroenterology Service of the Hospital Universitari Vall d'Hebron (HUVH) (Spain). Demographic, clinical, and analytical variables were collected. Twenty SNPs potentially associated with variations in the response to infliximab plasma concentrations were analysed. infliximab serum concentrations and antibodies to infliximab (ATI) were determined by ELISA. PopPK modelling was performed using nonlinear mixed-effects analysis (NONMEM). RESULTS: Thirty patients (21 males) were included. The median age (range) at the start of infliximab treatment was 13 years (16 months to 16 years). A total of 190 samples were obtained for model development (49 [25.8%] during the induction phase). The pharmacokinetics (PK) of infliximab were described using a two-compartment model. Weight, erythrocyte sedimentation rate (ESR), faecal calprotectin (FC), and the SNP rs1048610 (ADAM17) showed statistical significance for clearance (CL), and albumin for inter-compartmental clearance (Q). Estimates of CL1 (genotype 1-AA), CL2 (genotype 2-AG), CL3 (genotype 3-GG), Q, Vc, and Vp (central and peripheral distribution volumes) were 0.0066 L/h/46.4 kg, 0.0055 L/h/46.4 kg, 0.0081 L/h/46.4 kg, 0.0029 L/h/46.4 kg, 0.6750 L/46.4 kg, and 1.19 L/46.4 kg, respectively. The interindividual variability (IIV) estimates for clearance, Vc, and Vp were 19.33, 16.42, and 36.02%, respectively. CONCLUSIONS: A popPK model utilising weight, albumin, FC, ESR, and the SNP rs1048610 accurately predicted infliximab trough concentrations in children with IBD.

A Gastroenterologist's guide to drug interactions of small molecules for inflammatory bowel disease.

Small molecule drugs are becoming increasingly used in the treatment of inflammatory bowel diseases (IBD). However, unlike monoclonal antibody drugs, which have few interactions with other medications, the pharmacokinetics of small molecule drugs are complex and may be influenced by a myriad of drug-drug interactions (DDI) as well as by patient characteristics and food intake. This review aims to provide a concise practical guide to small molecule drug interactions for the use of IBD physicians. It starts with a brief overview of the main metabolizing enzymes and transporters involved in drug interactions and the Food and Drug Administration's (FDA) approach to determining drug-interaction hazard thresholds. It is then followed by a more detailed review of the pharmacokinetics of five novel small molecules approved in IBD: Tofacitinib, Upadacitinib, Filgotinib, Ozanimod, and Etrasimod, including their known interactions and specific warnings. This review will also inform readers on challenges in determining the actual magnitude of interactions and their clinical relevance, including the arbitrary nature of some hazard thresholds, the inference of the impact on metabolizing enzymes and transporters from single-drug assays which may not reflect poly-pharmaceutical regimens, and other challenges in this field which the IBD physician needs to be cognizant of. In practice, before administering a small molecule drug, it is advisable to evaluate any potential interactions with other medications the patient is receiving. An increased awareness by health care professionals and patients, may reduce the possible risks associated with DDI of small molecule IBD drugs.

Performance of Eight Infliximab Population Pharmacokinetic Models in a Cohort of Dutch Children with Inflammatory Bowel Disease.

BACKGROUND AND OBJECTIVE: Efficacy of infliximab in children with inflammatory bowel disease can be enhanced when serum concentrations are measured and further dosing is adjusted to achieve and maintain a target concentration. Use of a population pharmacokinetic model may help to predict an individual's infliximab dose requirement. The aim of this study was to evaluate the predictive performance of available infliximab population pharmacokinetic models in an independent cohort of Dutch children with inflammatory bowel disease. METHODS: In this retrospective study, we used data of 70 children with inflammatory bowel disease (443 infliximab concentrations) to evaluate eight models that focused on infliximab pharmacokinetic models in individuals with inflammatory bowel disease, preferably aged ≤ 18 years. Predictive performance was evaluated with prior predictions (based solely on patient-specific covariates) and posterior predictions (based on covariates and infliximab trough concentrations). Model accuracy and precision were calculated with relative bias and relative root mean square error and we determined the classification accuracy at the trough concentration target of ≥ 5 mg/L. RESULTS: The population pharmacokinetic model by Fasanmade was identified to be most appropriate for the total dataset (relative bias before/after therapeutic drug monitoring: -20.7%/11.2% and relative root mean square error before/after therapeutic drug monitoring: 84.1%/51.6%), although differences between models were small and several were deemed suitable for clinical use. For the Fasanmade model, sensitivity and specificity for maximum posterior predictions for the next infliximab trough concentration to be ≥ 5 mg/L were respectively 83.5% and 80% with an area under the receiver operating characteristic curve of 0.870. CONCLUSIONS: In our paediatric cohort, various models provided acceptable predictive performance, with the Fasanmade model deemed most suitable for clinical use. Model-informed precision dosing can therefore be expected to help to maintain infliximab trough concentrations in the target range.

Switching from intravenous to subcutaneous infliximab maintenance therapy in inflammatory bowel disease: Post hoc longitudinal analysis of a randomized trial.

BACKGROUND: Pharmacokinetic non-inferiority of subcutaneous (SC) to intravenous (IV) CT-P13 maintenance therapy was demonstrated in a randomized trial (NCT02883452). This post hoc analysis evaluated longitudinal clinical outcomes with the two infliximab treatment strategies. METHODS: Patients with Crohn's disease or ulcerative colitis received CT­P13 IV loading doses (5 mg/kg; Week [W] 0 and W2) before randomization (1:1) to receive CT-P13 SC (body weight-based dosing every 2 weeks [Q2W]; W6-54; 'SC maintenance group') or CT­P13 IV (5 mg/kg Q8W; W6-22) then CT-P13 SC (Q2W; W30-54; 'IV-to-SC switch group'). Paired W30/W54 patient-level data were analyzed. RESULTS: Fifty-three (IV-to-SC switch) and fifty-nine (SC maintenance) patients were analyzed. Median trough serum CT-P13 concentrations were significantly higher at W54 versus W30 in the IV-to-SC switch group (20.4 versus 2.3 µg/mL; p < 0.00001), while remaining consistent in the SC maintenance group. Statistically significant improvements in pharmacokinetics, efficacy, fecal calprotectin levels, and quality of life were seen following switch to SC administration at W30 in the IV-to-SC switch group; safety findings were similar pre- and post-switch. CONCLUSION: Formulation switching from IV to SC infliximab maintenance therapy was well tolerated and may provide additional clinical improvements. Findings require confirmation in larger prospective studies.

Therapeutic drug monitoring of vedolizumab therapy in inflammatory bowel disease.

BACKGROUND: Therapeutic drug monitoring is effective for optimizing anti-tumor necrosis factor therapies in inflammatory bowel disease, but for vedolizumab, a gut-selective leucocyte migration inhibitor, data are scarce. METHODS: Observational cohort study including 116 bio-experienced inflammatory bowel disease patients treated with vedolizumab for active luminal disease. Biobanked trough blood samples (n = 676) covering 96% of patients were analyzed using a drug-binding immunofluorometric assay. Steroid-free treatment outcomes were classified by clinical disease activity indices and objective findings, primarily endoscopy. RESULTS: Patients with clinical remission to vedolizumab induction therapy (37%) had significantly higher trough levels than those without at weeks 6 (mean 34.1 vs 28.0 µg/mL, P = 0.03) and 10 (34.8 vs 27.5 µg/mL, P = 0.01). Optimal thresholds for discrimination were 32.4 µg/mL (AUCROC 0.66, P = 0.04) and 23.5 (AUCROC 0.67, P = 0.01), respectively. This positive association persisted during maintenance phase with 11.9 µg/mL (AUCROC 0.69, P < 0.01) associated with clinical remission (37%) and 15.3 (AUCROC 0.74, P < 0.001) for objective remission (46%). Stratification by temporal evolution of treatment effects revealed higher induction and maintenance vedolizumab levels in persistent and slow responders as compared to secondary or persistent failures. Pharmacokinetics was influenced by rare formation of anti-vedolizumab antibodies (2%), and to a lesser extent gender and albumin during induction, but not disease severity, concomitant steroids, or thiopurine metabolites. Switching to subcutaneous administrations resulted in 2.3-fold increase in steady-state trough levels. CONCLUSION: Our study supports maintaining adequate drug exposure being essential for sustained positive outcomes of vedolizumab and emphasizes individualized, therapeutic drug monitoring-based treatment regimens. Controlled trials and pharmacokinetic modeling are, however, needed.

The Influence of Subclinical Active Inflammation on IFX Pharmacokinetic Modeling and Disease Progression Assessment: Findings from a Prospective Real-World Study in Inflammatory Bowel Disease Patients.

BACKGROUND AND AIMS: Effective management of inflammatory bowel disease (IBD) relies on a comprehensive understanding of infliximab (IFX) pharmacokinetics (PK). This study's primary goal was to develop a robust PK model, identifying key covariates influencing IFX clearance (CL), while concurrently evaluating the risk of disease progression during the maintenance phase of IBD treatment. METHODS: The multicenter, prospective, real-world DIRECT study was conducted in several care centers, which included 369 IBD patients in the maintenance phase of IFX therapy. A two-compartment population PK model was used to determine IFX CL and covariates. Logistic and Cox regressions were applied to elucidate the associations between disease progression and covariates embedded in the PK model. RESULTS: The PK model included the contributions of weight, albumin, antidrug antibody (ADA), and fecal calprotectin (FC). On average, higher ADA, FC concentration and weight, and lower albumin concentration resulted in higher IFX CL. In the multivariate regression analyses, FC levels influenced the odds of disease progression in the majority of its definitions, when adjusted for several confounding factors. Additionally, alongside FC, both IFX and CL demonstrated a significant impact on the temporal aspect of disease progression. CONCLUSION: In this 2-year real-world study, readily available clinical covariates, notably FC, significantly impacted IFX availability in IBD patients. We demonstrated that subclinical active inflammation, as mirrored by FC or CRP, substantially influenced IFX clearance. Importantly, FC emerged as a pivotal determinant, not only of IFX pharmacokinetics but also of disease progression. These findings underscore the need to integrate FC into forthcoming IFX pharmacokinetic models, amplifying its clinical significance.

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.

Infliximab serum concentrations in luminal Crohn's disease and its relationship with disease activity: A multicentric cross-sectional study.

OBJECTIVES: In Latin America, experience with monitoring serum Infliximab (IFX) concentrations is scarce. Our study aimed to compare IFX serum concentrations between patients with active disease or in remission. PATIENTS AND METHODS: A cross-sectional study was performed in patients with luminal Crohn's disease (CD) during maintenance treatment with IFX. Patients were classified as in remission or disease activity according to clinical scores and endoscopic, radiological, and laboratory markers. A comparison of IFX trough levels between the two groups was performed. RESULTS: 80 CD patients were included [41 (51%) in remission and 39 (49%) with active disease]. In the analysis of general disease activity, the median serum levels of IFX in patients with remission and with active CD were 5.63 [0.03-14.40] vs. 3.84 [0.03-14.40] (p=0.287). Furthermore, there was no difference in serum IFX concentrations in endoscopic, radiological, and laboratory activities. Only in the clinical evaluation there was a significant difference in the median serum IFX levels between patients in remission and disease activity, 5.63 [0.03-14.40] vs. 2.14 [0.32-10.54] (p=0.042). CONCLUSIONS: IFX serum concentrations during maintenance treatment were similar in patients with luminal CD in remission and general, endoscopic, radiological, and laboratory disease activity. Patients with clinically active disease had lower IFX concentrations than patients in remission.

Early Infliximab Clearance Predicts Remission in Children with Crohn's Disease.

BACKGROUND AND AIMS: Children with Crohn's disease have lower response rates to infliximab, lower infliximab levels, and higher infliximab clearance on weight-based dosing than adults. We hypothesize infliximab clearance is a predictive of later outcomes on infliximab in children with Crohn's disease. METHODS: In this single-center retrospective study, data were collected from charts on diagnosis, anthropometry, routine labs, infliximab therapeutic drug monitoring, infliximab dosing, disease activity, and other treatments. With these data we generated a population pharmacokinetic model using non-linear mixed effects modeling and calculated infliximab clearance for each patient over time. Patients were classified as in remission, responder-only or non-responder at 5, 10 and 16 months. Regression and ROC analyses were used to assess for early predictors of remission and response to infliximab. RESULTS: Eighty-five subjects were included, with a median follow-up of 22.3 months (IQR 10.1-36.8). Our pharmacokinetic model showed infliximab clearance was positively associated with CRP and weight, while negatively associated with albumin. In regression analyses, early infliximab clearance was the only significant, consistent predictor of remission. A 0.1 L/day increase in infliximab clearance predicted remission with an OR between 0.179 and 0.426. Differences in dosing did not account for differences in outcome. Infliximab clearance alone had moderate predictive accuracy of remission, with an AUC between 0.682 and 0.738. CONCLUSIONS: Early infliximab clearance is strongly associated with remission in children with Crohn's disease. It may be useful as a marker of response in proactive therapeutic drug monitoring to guide early dose optimization and/or changes in treatment for betterment of long-term outcomes.

Efficacy, safety, and pharmacokinetics of teduglutide in adult Japanese patients with short bowel syndrome and intestinal failure: two phase III studies with an extension.

PURPOSE: The short- and long-term efficacy, safety, and pharmacokinetics of teduglutide were analyzed in adult Japanese patients with short bowel syndrome and intestinal failure (SBS-IF). METHODS: Patients received teduglutide 0.05 mg/kg/day in clinical trials (TED-C14-004, SHP633-306, and extension SHP633-307). Data were analyzed at 24 weeks and an interim data cut-off of 4.5 years. RESULTS: The parenteral support (PS) volume decreased by ≥ 20% for 9/18 patients at 24 weeks and in all 11 patients by data cut-off in SHP633-307. The mean (standard deviation) PS volume decreased from baseline at 24 weeks in TED-C14-004 (-30.1 ± 25.9%) and SHP633-306 (-25.6 ± 25.5%), and at data cut-off in SHP633-307 (-57.08 ± 28.49%). Teduglutide was absorbed quickly. The adverse events were consistent with the underlying disease and known adverse drug reactions. Anti-teduglutide antibody titers declined with long-term treatment. CONCLUSIONS: In Japanese adults with SBS-IF, teduglutide treatment was associated with clinically meaningful reductions in PS requirements, similar to findings in prior international studies. No new safety concerns specific to the Japanese SBS-IF patient population were identified with short- or long-term teduglutide treatment. Anti-teduglutide antibody titers disappeared in most Japanese adults with long-term treatment. These results constitute the longest evaluation of teduglutide treatment within clinical trials reported to date.

Pharmacokinetics, Safety and Efficacy of Intravenous Vedolizumab in Paediatric Patients with Ulcerative Colitis or Crohn's Disease: Results from the Phase 2 HUBBLE Study.

BACKGROUND AND AIMS: To date, there are no systematic pharmacokinetic [PK] data on vedolizumab in paediatric inflammatory bowel disease [IBD]. We report results from HUBBLE, a dose-ranging, phase 2 trial evaluating the PK, safety and efficacy of intravenous vedolizumab for paediatric IBD. METHODS: Enrolled patients [aged 2-17 years] with moderate to severe ulcerative colitis [UC] or Crohn's disease [CD] and body weight ≥10 kg were randomized by weight to receive low- or high-dose vedolizumab [≥30 kg, 150 or 300 mg; <30 kg, 100 or 200 mg] on Day 1 and Weeks 2, 6 and 14. Week 14 assessments included PK, clinical response and exposure-response relationship. Safety and immunogenicity were assessed. RESULTS: Randomized patients weighing ≥30 kg [UC, n = 25; CD, n = 24] and <30 kg [UC, n = 19; CD, n = 21] had a baseline mean [standard deviation] age of 13.5 [2.5] and 7.6 [3.2] years, respectively. In almost all indication and weight groups, area under the concentration curve and average concentration increased ~2-fold from low to high dose; the trough concentration was higher in each high-dose arm compared with the low-dose arms. At Week 14, clinical response occurred in 40.0-69.2% of patients with UC and 33.3-63.6% with CD in both weight groups. Clinical responders with UC generally had higher trough concentration vs non-responders, while this trend was not observed in CD. Fourteen per cent [12/88] of patients had treatment-related adverse events and 6.8% [6/88] had anti-drug antibodies. CONCLUSIONS: Vedolizumab exposure increased in an approximate dose-proportional manner. No clear dose-response relationship was observed in this limited cohort. No new safety signals were identified.

Collecting New Peak and Intermediate Infliximab Levels to Predict Remission in Inflammatory Bowel Diseases.

BACKGROUND: The loss of response to infliximab is a challenge for clinicians in the management of inflammatory bowel disease (IBD). Mounting evidence suggests that therapeutic drug monitoring at induction may predict remission during maintenance. The aim of the study was to improve predictive models of remission by exploring new peak and intermediate infliximab measurements during induction. METHODS: This was a prospective multicenter study evaluating the pharmacokinetics of infliximab during induction in a pioneer cohort of 63 patients with IBD. Pharmacokinetics data including peak, intermediate, and trough levels were combined with clinical and biological parameters and were subsequently fed into tailored logistic regression and tree-based techniques to predict remission at week 30. RESULTS: Infliximab peak levels at week 2, intermediate levels at week 3, and trough levels at week 6 were correlated with remission at week 30. Predictive models exhibited an increased accuracy over the successive timepoints of the induction with key inputs such as albumin, C-reactive protein, eosinophils, neutrophils, lymphocytes, intermediate level at week 3, trough level at week 6, and age at diagnosis. Our predictive model of remission at week 30 was obtained with an area under the receiver operating characteristic curve of 0.9 ±â€…0.12, a sensitivity of 89%, and a specificity of 75%. CONCLUSIONS: This study showed the clinical relevance of measuring new infliximab levels to predict remission in patients with IBD. These findings lay the foundation for a personalized medicine in which biotherapies could be monitored at an early stage, thereby improving patients' clinical management.