Infliximab dose intensification by shortening infusion intervals

Treatment Targets Should Influence Choice of Infliximab Dose Intensification Strategy in Inflammatory Bowel Disease: A Pharmacokinetic Simulation Study

BACKGROUND

The optimal infliximab dose intensification strategy to address loss of response associated with subtherapeutic infliximab trough levels remains uncertain, as does whether post-intensification trough and treatment targets should influence this decision.

OBJECTIVES

This pharmacokinetic simulation study aimed to identify infliximab dose intensification strategies capable of achieving post-intensification infliximab trough thresholds associated with clinical and objective treatment targets in Crohn's disease and ulcerative colitis.

METHODS

A validated pharmacokinetic infliximab model, applied to 200 simulated patients, identified those with subtherapeutic (< 3.00 mg/L) trough levels after 30 weeks of standard (5 mg/kg 8-weekly) dosing, and subsequently applied 10 dose intensification strategies over a further 32 weeks. The proportion of simulations achieving 32-week post-intensification infliximab trough levels associated with endoscopic remission (ulcerative colitis > 7.50 mg/L, Crohn's disease > 9.70 mg/L) was the primary outcome, with perianal fistula healing (Crohn's disease > 10.10 mg/L) and clinical improvement (ulcerative colitis > 3.70 mg/L, Crohn's disease > 7.00mg/L) evaluated as secondary outcomes. All outcomes were stratified by intensity of dose intensification, with standard (≤ 10 mg/kg 8-weekly or 5 mg/kg 4-weekly; n = 5) and intensive (> 10 mg/kg 8-weekly or 5 mg/kg 4-weekly; n = 5) dosing strategies defined, respectively.

RESULTS

The median pre-intensification infliximab trough level was 0.91 mg/L (interquartile range 1.37). Intensive dosing strategies were more likely to achieve infliximab trough concentrations associated with endoscopic remission (ulcerative colitis 36.48% vs. 10.80%, Crohn's disease 25.98 vs. 4.68%), perianal fistula healing (24.52% vs. 4.36%) and clinical improvement (ulcerative colitis 61.90% vs. 34.86%, Crohn's disease 40.32 vs. 12.08%) than standard intensification strategies (all p < 0.01). When controlling for cumulative (mg/kg) infliximab dose over 32 weeks, strategies that concurrently dose increased and interval shortened achieved the highest infliximab trough levels (all p < 0.01).

CONCLUSION

This simulation-based analysis highlights the potential of using post-intensification infliximab trough thresholds associated with aspirational treatment targets in Crohn's disease and ulcerative colitis to guide choice of infliximab dose intensification strategy. Intensive dose intensification strategies, particularly those that concurrently dose increase and interval shorten, appear to achieve higher infliximab levels than standard dose intensification strategies. This may be particularly important in the pursuit of stringent endpoints, such as endoscopic remission and fistula healing, which have been consistently associated with higher infliximab trough levels. These findings require validation across real-world cohorts.

Dose escalation of biologics in Crohn's disease: critical review of observational studies

BACKGROUND

Biologics used to treat Crohn's disease (CD) may lose their effect over time, requiring dose escalation. Little information is available on this topic.

AIM

To summarize rates of dose escalation, duration, de-escalation in observational studies of CD in adults treated with adalimumab, infliximab, and vedolizumab in Europe.

METHODS

Two independent investigators searched Medline and Embase for observational studies published in 1998-2015 and proceedings from four major scientific meetings. Rates were summarized descriptively.

RESULTS

In total, 58 articles from 12 European countries were analyzed (49 full articles, nine abstracts), providing 65 reports with 7,850 patients; 35 reported on 3,830 patients with adalimumab (ADA), and 30 on 4,020 patients with infliximab (IFX). Overall, 29.9% ± 3.5% of patients required dose escalation; 32.8% ± 6.2% with ADA and 25.2% ± 2.4% with IFX (p = .35 between drugs). Rates increased according to line of treatment: 19% for first line, 37% second, and 41% third. The median time to loss of response was 12 months, and the weighted average was 15.1 ± 5.9 months. Median time to escalation was 6.7 months; 6.7 months for ADA and 7.5 for IFX (p = .86). Short-term response rates to escalation were 63% for ADA and 45% for IFX (p = .08). There were no papers available for vedolizumab.

CONCLUSIONS

A substantial proportion of patients receiving ADA or IFX for Crohn's disease require dose escalation after a short period of time.

Durability of infliximab dose intensification in Crohn's disease

BACKGROUND

Dose intensification is a common approach to treat Crohn's disease (CD) patients who lose response to infliximab maintenance therapy. Few studies have reported upon its long-term efficacy or predictors of response.

AIM

The goal of this study is to investigate durability and predictors of response to dose intensification-including method of dose intensification, combination immunomodulator therapy, and premedication with intravenous hydrocortisone.

METHODS

We performed a retrospective study of dose-intensified CD patients at our institution. Dose intensification was defined as an increase in dose from 5 to 10 mg/kg, an increase in frequency of infusions from every 8 weeks to every 6 weeks or less, or both an increase in dose and frequency.

RESULTS

Thirty CD patients (mean age, 39.9 years) met study criteria and underwent dose intensification. Ten (33.3%) patients remained on dose intensification at the end of our study or returned to their former infliximab dose or schedule (median follow-up, 41 months). Fourteen patients (46.7%) eventually lost response to dose intensification, but dose intensification extended infliximab therapy by a median duration of 9 months. Six patients (20%) didn't respond to dose intensification. Neither method of dose intensification, combination immunomodulator therapy, nor premedication with intravenous hydrocortisone predicted initial or durable response to dose intensification. However, analysis of predictors was limited by the small sample size of our study.

CONCLUSIONS

The majority of CD patients respond to dose intensification, and a substantial portion will experience durable response such that infliximab therapy is successfully extended by one or more years.

Individualized treatment with infliximab therapy in children with Crohn’s disease support shorter time intervals between infusions

Objectives

To study the effect of an individualized treatment approach with regard to dosage intervals between infliximab infusions on the clinical outcome of pediatric Crohn’s disease (CD).

Patients and methods

A retrospective analysis of medical records of all pediatric patients with CD who had been treated with infliximab between 1999 and 2007 in two Swedish counties, where an individualized treatment approach had been applied.

Results

Twenty-nine patients were included in the study. The number of infusions varied from 2 to 47 (median: 8). Nineteen patients received more than 5 infusions and 13 patients received more than 10 infusions. Most of the patients did not stay in remission when the dosage interval was 8 weeks or longer.

Conclusions

An individualized treatment approach, based on the physician’s desire to treat, resulted in shorter dosage intervals than 8 weeks between infliximab infusions in a majority of pediatric patients with CD. The retrospective design of the study must be taken into account when interpreting the results.

The efficacy of shortening the dosing interval to once every six weeks in Crohn's patients losing response to maintenance dose of infliximab

BACKGROUND

Patients treated with infliximab for Crohn's disease (CD) frequently require intensified dosage due to loss of response. There are scant data regarding the efficacy of shortening the dosing interval to 6 weeks.

AIM

We sought to investigate the efficacy of a once every 6 weeks' strategy compared with dose-doubling.

METHODS

This work was a multicentre retrospective study of infliximab-treated CD patients who required dose escalation. The clinical outcome of patients treated by intensification to 5 mg/kg/6 weeks (6-week group) was compared with the outcome of patients whose infliximab was double-dosed (10 mg/kg/8 weeks or 5 mg/kg/4 weeks).

RESULTS

Ninety-four patients (mean age: 29.8 years) were included in the study, 55 (59%) in the 6-week group and 39 (41%) in the double-dose group. Demographics and disease characteristics were similar between the two groups, although patients with re-emerging symptoms 5-7 weeks postinfusion were more likely to receive 5 mg/kg/6 weeks dosing (OR: 3.4, 95% CI: 1.4-8.8, P < 0.01). Early response to dose-intensification occurred in 69% of patients in the 6-week group and 67% in the double-dose group (P = N.S.). Regained response was maintained for 12 months in 40% compared with 29% of the patients respectively (P = N.S.).

CONCLUSION

In CD patients who lost response to standard infliximab dose, especially when symptoms re-emerge 5-7 weeks postinfusion, shortening the dosing interval to 6 weeks appears to be at least as effective as doubling the dose to 10 mg/kg or halving the infusion intervals to once in 4 weeks.

Systematic review: steroid withdrawal in anti-TNF-treated patients with inflammatory bowel disease

BACKGROUND

The increasing awareness of increased risk for opportunistic infections when combining several immunosuppressant drugs led to new treatment goals for inflammatory bowel disease including limited use of steroids.

AIM

To conduct a systematic review to establish figures for steroid withdrawal in anti-TNF treated inflammatory bowel disease-patients.

METHODS

Medline was searched using the search-terms Ulcerative Colitis (UC) [Mesh], Crohn Disease (CD) [Mesh], IBD [Mesh], crohn, colitis, IBD and steroid sparing, all combined with infliximab and adalimumab. We selected English-language publications that addressed the effect of anti-TNF on steroid withdrawal. Studies had to assess patients with luminal CD or UC. Numbers of patients who were able to withdraw steroids were calculated.

RESULTS

Six studies could be included; five reporting on infliximab and one on adalimumab. Studies were heterogeneously designed. Overall, in the adult population, up to 38% of the patients were able to withdraw corticosteroids during infliximab therapy. In the paediatric population, up to 75% of the patients were able to withdraw corticosteroids during infliximab therapy.

CONCLUSIONS

Although a consensus on the definition of steroid-sparing is lacking, approximately two-thirds of the inflammatory bowel disease-patients are unable to withdraw corticosteroid treatment during anti-TNF therapy.