Systematic Review and Meta-analysis: Loss of Response and Need for Dose Escalation of Infliximab and Adalimumab in Ulcerative Colitis

Fluorescence-Based Lateral Flow Immunoassay for Quantification of Infliximab: Analytical and Clinical Performance Evaluation

BACKGROUND

Therapeutic drug monitoring of infliximab (IFX) can improve treatment outcomes; however, the temporal gap between drug concentration monitoring and subsequent availability restricts its practical application. To address this issue, an automated monitoring method, AFIAS IFX, was developed to rapidly and accurately analyze IFX concentration in blood. The analytical and clinical performances of this method were assessed to establish its clinical utility.

METHODS

The analytical performance of AFIAS IFX was evaluated according to Clinical and Laboratory Standard Institute guidelines. For clinical validation, AFIAS IFX was compared with 3 established enzyme-linked immunosorbent assay kits (LISA TRACKER, RIDASCREEN, and ImmunoGuide) using 100 consecutive samples from 28 patients treated with IFX. Passing-Bablok regression and Bland-Altman analyses were performed to compare the methods.

RESULTS

The detection and quantification limits of AFIAS IFX were 0.12 and 0.20 mcg/mL, respectively. Furthermore, AFIAS IFX analyzed samples within 10 minutes for concentrations up to 50 mcg/mL, exhibiting reproducibility (coefficient of variation [CV] ≤7.8%) and accuracy (recovery 98%-101%) with serum, plasma, and whole blood samples. Clinically, it exhibited a good correlation with the 3 established enzyme-linked immunosorbent assay kits. For patients treated with Remicade (IFX), the Passing-Bablok regression slope was 1.001-1.259, with a mean difference of -1.48 to 0.28 mcg/mL. For patients treated with CT-P13, the Passing-Bablok regression slope was 0.974-1.254, with a mean difference of -2.44 to 0.15 mcg/mL.

CONCLUSIONS

AFIAS IFX, a novel fluorescence-based lateral flow assay, exhibited excellent performance in analyzing IFX trough levels and is a potentially powerful tool for therapeutic drug monitoring in clinical settings, with opportunities for further development.

Prognosis of pediatric ulcerative colitis after infliximab failure: A multicenter registry-based cohort study

BACKGROUND AND AIM

Even with increasing numbers of biologic agents available for management of ulcerative colitis (UC), infliximab (IFX) retains an important place in treatment of pediatric patients with this disease. As few reports have addressed outcomes in pediatric UC patients who had to discontinue IFX, we examined clinical course and prognosis after IFX failure in pediatric UC.

METHODS

A prospective cohort study of pertinent cases enrolled in the Japanese Pediatric Inflammatory Bowel Disease Registry between 2012 and 2020 was conducted to determine outcomes for pediatric UC patients who received IFX but required its discontinuation during follow-up (IFX failure).

RESULTS

Of the 301 pediatric UC patients in the registry, 75 were treated with IFX; in 36 of these, IFX was discontinued during follow-up. Severity of UC at onset and absence of concomitant immunomodulator therapy were significant risk factors for IFX failure (P = 0.005 and P = 0.02, respectively). The cumulative colectomy rate after IFX failure was 41.3% at 1 year and 47.5% at 2 years. Colectomy was significantly more frequent when IFX was discontinued before June 1, 2018, than when IFX was discontinued later (P = 0.013). This difference likely involves availability of additional biologic agents for treatment of UC beginning in mid-2018 (P = 0.005).

CONCLUSION

In pediatric UC patients, approximately 50% underwent colectomy during a 2-year interval following IFX failure. Prognosis after IFX failure appeared to improve with availability of new biologic agents and small-molecule drugs in mid-2018.

Predictors of Efficacy of Janus Kinase Inhibitors in Patients Affected by Ulcerative Colitis

Personalised medicine and the identification of predictors of the efficacy of specific drugs represent the ultimate goal for the treatment of ulcerative colitis (UC) in order to break the current therapeutic ceiling. JAK inhibitors are a new class of advanced therapies, orally administered, showing a good profile of efficacy and safety in both randomised controlled trials (RCTs) and real-world studies. Unfortunately, to date, it is not possible to draw the ideal profile of a patient maximally benefiting from this class of drugs to guide clinicians' therapeutic choices. Baseline clinical activities and inflammatory biomarkers, as well as their early variation after treatment initiation, emerged as the main predictors of efficacy from post hoc analyses of RCTs with tofacitinib. Similar findings were also observed in the real-life studies including mainly patients with a history of pluri-refractoriness to biological therapies. At last, a few new biomarkers have been explored, even though they have not been validated in large cohorts. This paper provides a review of the current knowledge on clinical variables and biomarkers predicting response to JAK inhibitors in UC.

Endoscopic healing is associated with a reduced risk of biologic treatment failure in patients with ulcerative colitis

Increasing number of patients with ulcerative colitis (UC) have received biologic treatment during the last decade. The association between endoscopic healing (EH) and biologic treatment failure remains understudied. Medical information of UC patients who started biologic treatment was retrospectively collected. EH was defined as Mayo endoscopic subscore of 0 or 1. Loss of response (LOR)-free drug continuation rate was compared between patients who achieved EH and those who did not using Kaplan-Meier estimator. Fifty-two patients received 53 biologic treatments and underwent follow-up colonoscopies within 2 years. Thirty-three patients achieved EH, all of which remained on the same treatment without LOR during the observational period. Twenty patients did not achieve EH, 8 of which ultimately discontinued the treatment due to LOR to biologic agents. Kaplan-Meier estimator found a significantly lower drug continuation rate in patients without EH (p < 0.001; log-rank test). A Cox regression analysis identified EH as an independent factor associated with a reduced risk of LOR-related biologic treatment failure irrespective of the types of biologic agents (Hazard Ratio = 0.0324, p < 0.001). EH within 2 years is associated with a reduced risk of LOR-related biologic treatment failure in patients with UC.

Comparative study of a point-of-care test and an enzyme-linked immunosorbent assay (ELISA) for infliximab levels

BACKGROUND

Proactive therapeutic drug monitoring (TDM) is often challenged by long turnaround time when using enzyme-linked immunosorbent assays (ELISAs), especially when analyses are centralised. Point-of-care tests (POCTs) allow rapid assessments, but data on their agreement with existing in-house methodologies are scarce.

OBJECTIVE

To examine the agreement between a POCT by ProciseDx (San Diego, CA) and the most frequently used in-house ELISA for infliximab (IFX) quantification in Sweden.

METHODS

Serum samples were analysed using the in-house ELISA, Karolinska University Hospital, Stockholm, Sweden and a POCT by ProciseDx (San Diego, CA). Agreement was assessed and differences were examined.

RESULTS

Samples from 61 inflammatory bowel disease (IBD) patients were analysed with a median IFX concentration of 7.9 μg/mL (interquartile range (IQR) 5.5-13) for the POCT and 7.9 μg/mL (IQR 5.2-12) for the ELISA (Pearson's correlation coefficient = 0.95 (95% CI 0.92-0.97, p < .01)). A Passing-Bablok regression yielded an intercept of -0.44 and a slope of 1.09. The Bland-Altman plot showed a systemic bias of -0.77 μg/mL (95% CI -0.18 to -1.4) between the methods. The upper limit of agreement was 3.7 (95% CI 2.7-4.8) (μg/mL), whereas the lower limit agreement was -5.3 (95% CI -6.3 to -4.3) (μg/mL). An excellent reliability was observed, intraclass correlation showed = 0.94 (95% CI 0.89-0.96, p < .0001). When defining IFX concentration as subtherapeutic (<3.0 μg/mL), therapeutic (3.0-7.0 μg/mL) or supratherapeutic (>7.0 μg/mL) drug levels, Kappa statistics showed a substantial agreement (0.79).

CONCLUSIONS

The POCT by ProciseDx (San Diego, CA) demonstrated a good agreement with the in-house ELISA, supporting its use for rapid IFX quantification.

Multiple infliximab biosimilar switches appear to be safe and effective in a real-world inflammatory bowel disease cohort

BACKGROUND

Switching from originator infliximab (IFX) to biosimilar IFX is effective and safe. However, data on multiple switching are scarce. The Edinburgh inflammatory bowel disease (IBD) unit has undertaken three switch programmes: (1) Remicade to CT-P13 (2016), (2) CT-P13 to SB2 (2020), and (3) SB2 to CT-P13 (2021).

OBJECTIVE

The primary endpoint of this study was to assess CT-P13 persistence following switch from SB2. Secondary endpoints included persistence stratified by the number of biosimilar switches (single, double and triple), effectiveness and safety.

METHODS

We performed a prospective, observational, cohort study. All adult IBD patients on IFX biosimilar SB2 underwent an elective switch to CT-P13. Patients were reviewed in a virtual biologic clinic with protocol driven collection of clinical disease activity, C-reactive protein (CRP), faecal calprotectin (FC), IFX trough/antibody levels, and drug survival.

RESULTS

297 patients (CD n = 196 [66%], ulcerative colitis/inflammatory bowel disease unclassified n = 101, [34%]) were switched (followed-up: 7.5 months [6.8-8.1]). This was the third, second and first IFX switch for 67/297 (22.5%), 138/297 (46.5%) and 92/297 (31%) of the cohort respectively. 90.6% of patients remained on IFX during follow-up. The number of switches was not independently associated with IFX persistence after adjusting for confounders. Clinical (p = 0.77), biochemical (CRP ≤5 mg/ml; p = 0.75) and faecal biomarker (FC<250 µg/g; p = 0.63) remission were comparable at baseline, week 12 and week 24.

CONCLUSION

Multiple successive switches from IFX originator to biosimilars are effective and safe in patients with IBD, irrespective of the number of IFX switches.