Successful Infliximab Treatment is Associated With Reversal of Clotting Abnormalities in Inflammatory Bowel Disease Patients.

BACKGROUND AND GOALS: Active inflammatory bowel diseases (IBD) represent an independent risk factor for venous thromboembolism. The authors investigated the hemostatic profile of IBD patients before and after induction treatment with infliximab, vedolizumab, and methylprednisolone. STUDY: This prospective study included 62 patients with active IBD starting infliximab, vedolizumab, and/or methylprednisolone, and 22 healthy controls (HC). Plasma was collected before (w0) and after induction therapy (w14). Using a clot lysis assay, amplitude (marker for clot intensity), time to peak (Tmax; marker for clot formation rate), area under the curve (AUC; global marker for coagulation/fibrinolysis), and 50% clot lysis time (50%CLT; marker for fibrinolytic capacity) were determined. Plasminogen activator inhibitor-1 (PAI-1) and fibronectin were measured by ELISA. Clinical remission was evaluated at w14. RESULTS: At baseline, AUC, amplitude, and 50%CLT were significantly higher in IBD patients as compared with HC. In 34 remitters, AUC [165 (103-229)% vs. 97 (78-147)%, P=0.001], amplitude [119 (99-163)% vs. 95 (82-117)%, P=0.002], and 50%CLT [122 (94-146)% vs. 100 (87-129)%, P=0.001] decreased significantly and even normalized to the HC level. Vedolizumab trough concentration correlated inversely to fibronectin concentration (r, -0.732; P=0.002). The increase in Tmax for infliximab-treated remitters was significantly different from the decrease in Tmax for vedolizumab-treated remitters (P=0.028). The 50%CLT increased (P=0.038) when remitters were concomitantly treated with methylprednisolone. CONCLUSIONS: Control of inflammation using infliximab most strongly reduced those parameters that are associated with a higher risk of venous thromboembolism.

Comparison of Immunoassays for Measuring Serum Levels of Golimumab and Antibodies Against Golimumab in Ulcerative Colitis: A Retrospective Observational Study.

BACKGROUND: Golimumab is a monoclonal anti-tumor necrosis factor alpha antibody, which is used in ulcerative colitis with an exposure-response relationship. The goal of this study was to compare results obtained with different immunoassays (golimumab and antigolimumab antibodies trough levels). METHODS: This study was based on samples from 78 ulcerative colitis patients on golimumab treatment. Golimumab was quantified by either an anti-IgG detection antibody (Theradiag, Marne la Vallée, France) or an antibody directed against golimumab (Sanquin, Amsterdam, The Netherlands, KU Leuven, Leuven, Belgium, and Janssen R&D, San Diego, CA). Bridging drug-sensitive enzyme-linked immunosorbent assays (Theradiag, Janssen R&D, and KU Leuven), a bridging drug-tolerant enzyme-linked immunosorbent assay (Janssen R&D), and a radioimmunoassay (Sanquin) were used to quantify antidrug antibody. RESULTS: Median serum golimumab levels were 4.5, 3.5, 4.9, and 2.4 mcg/mL with Theradiag, Sanquin, KU Leuven, and Janssen R&D assay, respectively (P < 0.05). Correlation coefficients between assays ranged from 0.9 to 0.97. When using the KU Leuven and Janssen R&D assays, 86% of samples were in the same quartile of distribution of values, and for Sanquin and Janssen R&D assays, this overlap was 80%. The concordance observed for the other pairs was 83% (Sanquin/KU Leuven R&D), 71% (Theradiag/KU Leuven), and 68% (Theradiag/Janssen R&D and Theradiag/Sanquin). The specificity of assays for golimumab was demonstrated. Antidrug antibodies were detected in 28.2% of the samples with the Janssen R&D drug-tolerant assay and in the same 2 patients by the 3 other assays. CONCLUSIONS: Performances of these immunoassays were similar in terms of quality, but differences in the quantitative results point to the importance of using the same assay consistently to monitor a patient's treatment.

Characterization and Application of a Unique Panel of Monoclonal Antibodies Generated against Etanercept.

The clinical response in ankylosing spondylitis (AS) patients treated with biologic agents can be influenced by pharmacokinetic variability among and within these patients. Therapeutic drug monitoring is seen as a valuable tool to improve patient care. The aim of this study was to generate a panel of mAbs toward etanercept (ETN) and to determine ETN and anti-ETN concentrations in AS patients. mAbs against ETN (MA-ETN) were generated using hybridoma technology. For quantification of ETN concentrations, a mAb-based TNF-coated ELISA and a mAb/mAb-based sandwich-type ELISA were developed. For evaluation of the anti-ETN Ab response, a bridging ELISA, as well as a functional cell-based assay, were constructed. Disease activity of the AS patients was measured with the AS Disease Activity Score (ASDAS). Active disease was defined as ASDAS ≥ 2.1. A total of 59 of 76 generated mAbs were ETN specific and were characterized further. Fifty-one mAbs revealed inhibitory properties in a cell-based assay. Analysis of serum concentrations of 21 ETN-treated AS patients with the TNF/MA-ETN68C5-HRP ELISA and the MA-ETN63C8/MA-ETN61C1-HRP ELISA revealed a good Pearson's r (+0.974) but a poor intraclass correlation coefficient (+0.528) as the result of underestimation of the values in the former ELISA. At 24 wk, ETN concentrations were similar in patients with ASDAS < 2.1 and ≥ 2.1. Anti-ETN Abs were not detected in any of the patient samples tested. In conclusion, highly sensitive mAb-based immunoassays were developed for quantification of ETN and anti-ETN concentrations. The impact of these methods needs to be evaluated further in clinical practice.

Immunoassay for Detection of Infliximab in Whole Blood Using a Fiber-Optic Surface Plasmon Resonance Biosensor.

Monitoring the concentration of a therapeutic drug antibody, infliximab (IFX), is recommended for enhancing its efficacy in patients with inflammatory bowel disease (IBD). However, IFX concentrations are currently determined in patients' serum/plasma, which requires sample preparation from blood, hence hampering the turnaround time. In this paper, we present a short immunoassay (10 min) using a fiber-optic surface plasmon resonance (FO-SPR) biosensor for detection of IFX spiked in 100-fold diluted serum, plasma, and whole blood. The calculated limits of detection (LOD) based on calibration curves were 1.42, 1.00, and 1.34 ng/mL, respectively, which coincides with expected IFX concentrations in diluted samples from IBD patients. A linear correlation was established among different matrixes, indicating that the matrix effect was insignificant. The established point-of-care (POC) FO-SPR bioassay was also used to measure IFX in 100-fold diluted extracts of dried blood spots (DBS), and LOD achieved was below 2 ng/mL. Although DBS might be ideal for POC, this is the first report of using an SPR biosensor for measuring DBS samples. Finally, the POC FO-SPR immunoassay was validated by using matching serum and plasma samples from five IBD patients. A Pearson correlation of 0.968 was obtained between serum and plasma samples. IFX concentrations determined with FO-SPR were compared to a clinically validated enzyme-linked immunosorbent assay (ELISA), resulting in excellent Pearson correlation and intraclass correlation coefficient, both being 0.99 for serum and plasma samples. In conclusion, this paper demonstrates that our FO-SPR biosensor can be used as a true POC diagnostic tool for determining IFX concentrations in a variety of matrixes.

The association between etanercept serum concentration and psoriasis severity is highly age-dependent.

The association between etanercept serum concentration and psoriasis disease severity is poorly investigated, and currently etanercept serum concentration monitoring that is aiming to optimize the psoriasis treatment lacks evidence. In this prospective study, we investigated the relation between etanercept exposure and disease severity via measuring etanercept concentrations at five consecutive time points in 56 psoriasis patients. Disease severity assessments included the Psoriasis Area and Severity Index (PASI), body surface area (BSA) and Physician Global Assessment (PGA), and etanercept and anti-etanercept antibody concentrations were determined every 3 months for a period of 1 year. The present study demonstrated that the association between etanercept concentration and psoriasis severity is age-dependent: when patients were stratified into three groups, patients in the youngest age group (-50 years) showed a lower PASI at a higher etanercept concentration (ß = -0.26), whereas patients in the oldest age group (+59 years) showed the opposite trend (ß =0.22). Similar age effects were observed in the relation of etanercept concentration with BSA (P=0.02) and PGA (P=0.02). The influence of age and length of time in therapy on the etanercept concentration-disease severity relation was unaffected by body mass index (BMI) or any other possible confounder. Incidence of anti-etanercept antibodies was low (2%). The age-dependent relation between etanercept serum concentrations is both unexpected and intriguing and needs further investigation.

Current Practice for Therapeutic Drug Monitoring of Biopharmaceuticals in Inflammatory Bowel Disease.

Since the late 90s, biopharmaceuticals targeting tumor necrosis factor alpha have revolutionized the treatment of moderately to severely active inflammatory bowel disease. The robust efficacy witnessed in many patients stands in stark contrast with the observation of a proportion of patients who fail to respond or who lose response over time. Therapeutic drug monitoring has been proposed as a means to understand and respond to the variability in clinical response and remission. Various treatment algorithms have been proposed, but optimal use of these measurements in daily practice awaits additional prospective validation trials. This review provides an updated overview on the subject of therapeutic drug monitoring of biopharmaceuticals for the management of inflammatory bowel disease and how we could implement its concepts in a changing landscape.

Endoscopic remission can be predicted by golimumab concentrations in patients with ulcerative colitis treated with the changed label.

BACKGROUND: In 2018, the European Medicines Agency (EMA) replaced a fixed 50 mg every 4-week maintenance regimen of golimumab for ulcerative colitis (UC) patients weighing <80 kg with new, flexible dosing that allows reactive dose optimization to 100 mg if clinically needed. We analyzed the endoscopic remission rates and pharmacokinetics of this new dosing regimen in real-life settings. METHODS: We prospectively recruited 30 consecutive (17 with body weight <80 kg) patients with UC who received golimumab with the new EMA label. The primary endpoint was endoscopic remission (Mayo ≤1) assessed by centrally-read endoscopy at week 14 and year 1. Golimumab concentrations, measured at nine prespecified timepoints, were correlated with endoscopic remission and identified cut-offs. RESULTS: Endoscopic remission was achieved in 15/30 (50%) and 10/30 (33%) patients at week 14 and year 1, respectively. Reactive dose optimization to 100 mg maintenance was needed in 13/17 (76%) patients. Golimumab concentrations at week 6 predicted week 14 and year 1 endoscopic remission. Week 6 concentrations >10.7 µg/ml were a strong predictor for achievement and maintenance of endoscopic remission during the first year of treatment, while concentrations <5.1 µg/ml identified the opposite. CONCLUSION: One-third of the patients reached and maintained endoscopic remission during the first year of golimumab treatment, but the need for dose optimization to 100 mg every 4 weeks of maintenance was high in patients weighing <80 kg. Golimumab concentrations <5.1 µg/ml at week 6 identified patients who are unlikely to reach and maintain endoscopic remission with the new, flexible EMA label.

A Population Pharmacokinetic and Exposure-Response Model of Golimumab for Targeting Endoscopic Remission in Patients With Ulcerative Colitis.

BACKGROUND: Unlike other anti-tumor necrosis factor alpha antibodies, golimumab does not deliver on its promise of effectiveness for treating patients with ulcerative colitis. We investigated the value of therapeutic drug monitoring for optimizing golimumab therapy. METHODS: We analyzed the golimumab pharmacokinetics data of 56 patients with moderate to severe ulcerative colitis. Induction and maintenance golimumab concentrations (296 venipuncture, 414 serum) were used to develop a population pharmacokinetic model. Exposure-response relationships were analyzed using the data of 40/56 patients with available endoscopy data. Receiver operating characteristic curve analysis was performed, and an exposure-response Markov model was developed, linking golimumab exposure to probabilities of transitioning between Mayo endoscopic subscore (MES) states from baseline to week (w)14. RESULTS: Golimumab pharmacokinetics was best described by a 2-compartment model with linear absorption and elimination. Antibodies to golimumab and previous biological therapy reduced golimumab exposure. Still, interindividual pharmacokinetic variability (IIVPK) remained largely unexplained. Endoscopic remission (ER; MESw14 ≤ 1) was achieved in 14/40 (35%) patients. Golimumab serum trough concentration thresholds of 7.4 mg/L (w6) and 3.2 mg/L (w14) predicted ER at w14 (positive predictive values [pv+] 83% and 91%, pv- 82% and 67%, respectively). The 3.2-mg/L target predicted 38% and 44% chances of achieving ER in patients with MESbaseline of 3 and 2, respectively. CONCLUSIONS: Personalized, model-based induction dosing aiming at here-established target concentrations may account for IIVPK and thus provide patients with more equal chances of achieving ER. As <50% of patients attained the exposure targets, higher golimumab induction dosing requires investigation to secure its future in clinical practice.

Golimumab Dried Blood Spot Analysis (GOUDA): a Prospective Trial Showing Excellent Correlation with Venepuncture Samples and More Detailed Pharmacokinetic Information.

Development of a dried blood spot (DBS) method for golimumab will facilitate sample collection in a study setting and will give a more complete insight in the total drug exposure (area under the curve, AUC). We established a DBS method and assessed its robustness, user-friendliness and clinical usefulness in 10 patients with ulcerative colitis during golimumab induction and maintenance regimens. DBS was obtained through spotting of golimumab spiked in whole citrated blood to a filter paper. Several extraction conditions were evaluated and the selected extraction condition analytically validated. In a clinical setting, DBS and serum samples were taken simultaneously through intensive sampling regimens and a conversion factor was determined. Golimumab concentrations were measured using an in-house-developed ELISA and a CE-marked ELISA kit. User-friendliness was evaluated using a questionnaire. Mucosal healing was evaluated at week 14. A total of 79 matched pairs of serum and DBS sample golimumab concentrations revealed an overall conversion factor of 3.9. DBS golimumab concentrations after conversion correlated strongly with serum golimumab concentrations (ICC = 0.984). During induction, no linear correlation was found between golimumab trough concentration (TC) and AUC (R2 = 0.29). Multiple peaks emerged during drug absorption. Patients who achieved mucosal healing appeared to have less fluctuating TC and a constant AUC over time. Nine out of 10 patients reported DBS sampling as user-friendly. The GOUDA study showed that DBS sampling is a robust and patient-friendly alternative to venous blood collection. DBS sampling may provide better insights into golimumab absorption and exposure. ( ClinicalTrials.gov NCT02910375).

Risk Assessment and Monitoring of Antibody Responses to Biosimilars in Chronic Inflammatory Diseases.

The expiry of the patent of several leading biological medicinal products has led to a surge in the development of 'biosimilar' products. However, in contrast to generic small-molecule medicines, biosimilars are not identical to their reference medicinal products. Full comparability in quality as well as in preclinical and clinical issues is required to register a biosimilar. The potential to induce antidrug antibodies after treatment with biological medicinal products is a safety issue that is an important consideration in the development of biosimilars and a critical aspect of regulatory filings. Regulatory authorities in the European Union require antidrug antibody responses to be evaluated and to be approached from a safety perspective: the higher the potential of immunogenicity to adversely affect a patient's health, the more diligently one should clarify the immunogenicity of the product. So far, however, no specific recommendations were given on a method for risk assessment or on the extent of the requisite antidrug antibody characterization. In this review, we will discuss the current state of knowledge on biosimilar products of infliximab, adalimumab and etanercept and present risk level-based schemes for the investigations of antidrug antibodies in non-clinical, clinical and pharmacovigilance studies.

Variability in Golimumab Exposure: A 'Real-Life' Observational Study in Active Ulcerative Colitis.

BACKGROUND AND AIMS: Golimumab has been approved recently to treat refractory moderate-to-severe ulcerative colitis [UC]. To date it is not clear why a considerable fraction of patients do not respond, or lose initial response, to golimumab therapy. Our aim was to investigate whether a low golimumab serum concentration and/or a positive anti-golimumab antibody status reduces the efficacy of this drug in patients with UC. METHODS: Serum samples of 21 patients with moderate-to-severe UC were collected during the first 14 weeks of golimumab therapy. For measurement of golimumab serum concentrations, both a tumour necrosis factor [TNF]-coated enzyme-linked immunosorbent assay [ELISA] and a sandwich-type ELISA were developed. Anti-golimumab antibodies were measured using a bridging ELISA and a newly-developed drug-tolerant immunoassay. Clinical response and mucosal healing were assessed 14 weeks after start of treatment. RESULTS: Out of 21 patients, 10 [48%] reached partial clinical response at Week 14. Median [interquartile range] serum golimumab concentration was significantly higher in partial clinical responders than in non-responders: 10.0 [7.8-10.5] µg/ml versus 7.4 [4.8-8.3] µg/ml at Week 2 [p = 0.035] and 5.1 [4.0-7.9] µg/ml versus 2.1 [1.8-4.2] µg/ml at week 6 [p = 0.037]. Four out of 21 UC patients developed anti-golimumab antibodies, detectable only using a drug-tolerant immunoassay, and three had a partial clinical response at that time. Clinical non-responders had a significantly more severe colitis, indicated by a higher endoscopic Mayo score at baseline compared with partial clinical responders [p = 0.048]. CONCLUSION: Adequate exposure to golimumab drives clinical response. A worse disease at baseline influences clinical response rate negatively.