Simulated cost-effectiveness of a novel precision-guided dosing strategy in adult patients with Crohn's disease initiating infliximab maintenance therapy.

BACKGROUND: Patients with Crohn's disease (CD) who lose response to biologics experience reduced quality of life (QoL) and costly hospitalizations. Precision-guided dosing (PGD) provides a comprehensive pharmacokinetic (PK) profile that allows for biologic dosing to be personalized. We analyzed the cost-effectiveness of infliximab (IFX) PGD relative to two other dose intensification strategies (DIS). METHODS: We developed a hybrid (Markov and decision tree) model of patients with CD who had a clinical response to IFX induction. The analysis had a US payer perspective, a base case time horizon of 5 years, and a 4-week cycle length. There were three IFX dosing comparators: PGD; dose intensification based on symptoms, inflammatory markers, and trough IFX concentration (DIS1); and dose intensification based on symptoms alone (DIS2). Patients that failed IFX initiated ustekinumab, followed by vedolizumab, and conventional therapy. Transition probabilities for IFX were estimated from real-world clinical PK data and interventional clinical trial patient-level data. All other transition probabilities were derived from published randomized clinical trials and cost-effectiveness analyses. Utility values were sourced from previous health technology assessments. Direct costs included biologic acquisition and infusion, surgeries and procedures, conventional therapy, and lab testing. The primary outcomes were incremental cost-effectiveness ratios (ICERs). The robustness of results was assessed via one-way sensitivity, scenario, and probabilistic sensitivity analyses (PSA). RESULTS: PGD was the cost-effective IFX dosing strategy with an ICER of 122,932 $ per quality-adjusted life year (QALY) relative to DIS1 and dominating DIS2. PGD had the lowest percentage (1.1%) of patients requiring a new biologic through 5 years (8.9% and 74.4% for DIS1 and DIS2, respectively). One-way sensitivity analysis demonstrated that the cost-effectiveness of PGD was most sensitive to the time between IFX doses. PSA demonstrated that joint parameter uncertainty had moderate impact on some results. CONCLUSIONS: PGD provides clinical and QoL benefits by maintaining remission and avoiding IFX failure; it is the most cost-effective under conservative assumptions.

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.

Nutritional Biomarkers for the Prediction of Response to Anti-TNF-α Therapy in Crohn's Disease: New Tools for New Approaches.

Crohn's disease (CD) is a chronic disorder of the digestive tract characterized by an uncontrolled immune-mediated inflammatory response in genetically predisposed individuals exposed to environmental risk factors. Although diet has been identified as one of the major environmental risk factors, the role of nutrients in the clinical management of CD patients has not yet been fully investigated. In this prospective observational study, fifty-four patients diagnosed with active Crohn's disease and undergoing anti-TNF-α biological therapy were enrolled and subjected to nutrient intake analysis through a daily food diary. Their nutrient intake and blood values were analyzed before and after 6 months of biological therapy. After 6 months of anti-TNF-α, four patients dropped out of the study, leaving 29 patients in clinical remission and 21 still with active disease that remained the same. The aim of this study was to identify nutrients whose intake or blood values may be associated with patients' responses to biological therapy. In the diet, patients remaining with active CD showed very similar nutrient dietary intake compared to patients achieving remission except for a trend for lower starting zinc intake, below the reference value. In the blood, instead, patients who did not respond to biological therapy showed significantly lower plasma values of iron and taurine before starting biological anti-TNF-α treatment.

Corrigendum: Poor prognostic factors of pharmacokinetic origin predict outcomes in inflammatory bowel disease patients treated with anti-tumor necrosis factor-α.

[This corrects the article DOI: 10.3389/fimmu.2024.1342477.].

Poor prognostic factors of pharmacokinetic origin predict outcomes in inflammatory bowel disease patients treated with anti-tumor necrosis factor-α.

Introduction: We evaluated baseline Clearance of anti-tumor necrosis factors and human leukocyte antigen variant (HLA DQA1*05) in combination as poor prognostic factors (PPF) of pharmacokinetic (PK) origin impacting immune response (formation of antidrug antibodies) and disease control of inflammatory bowel disease (IBD) patients treated with infliximab or adalimumab. Methods: Baseline Clearance was estimated in IBD patients before starting treatment using weight and serum albumin concentrations. HLA DQA1*05 carrier status (rs2097432 A/G or G/G variant) was measured using real time polymerase chain reaction. The outcomes consisted of immune response, clinical and biochemical remission (C-reactive protein<3 mg/L in the absence of symptoms), and endoscopic remission (SES-CD<3). Statistical analysis consisted of logistic regression and nonlinear mixed effect models. Results and discussion: In 415 patients enrolled from 4 different cohorts (median age 27 [IQR: 15-43] years, 46% females), Clearance>0.326 L/day and HLA DQA1*05 carrier status were 2-fold more likely to have antidrug antibodies (OR=2.3, 95%CI: 1.7-3.4; p<0.001, and OR=1.9, 95%CI: 1.4-2.8; p<0.001, respectively). Overall, each incremental PPF of PK origin resulted in a 2-fold (OR=2.16, 95%CI: 1.7-2.7; p<0.11) [corrected] higher likelihood of antidrug antibody formation. The presence of both PPF of PK origin resulted in higher rates of antidrug antibodies (p<0.01) and lower clinical and biochemical remission (p<0.01). Each incremental increase in PPF of PK origin associated with lower likelihood of endoscopic remission (OR=0.4, 95%CI: 0.2-0.7; p<0.001). Prior biologic experience heightened the negative impact of PPF of PK origin on clinical and biochemical remission (p<0.01). Implementation of proactive therapeutic drug monitoring reduced it, particularly during maintenance and in the presence of higher drug concentrations (p<0.001). We conclude that PPF of PK origin, including both higher Clearance and carriage of HLA DQA1*05, impact outcomes in patients with IBD.

Older Adults With Inflammatory Bowel Disease Are at Higher Risk of Developing Antibodies to Infliximab.

Although older age is thought to confer immunosenescence, we found that older adults with inflammatory bowel disease are independently at higher risk to develop antibodies to infliximab. Additionally, older adults are less likely to receive escalated doses of infliximab.