Real-world experience with subcutaneous infliximab: broadening treatment strategies for inflammatory bowel disease

Infliximab in Inflammatory Bowel Disease: Leveraging Physiologically Based Pharmacokinetic Modeling in the Clinical Context

In this study, a physiologically based pharmacokinetic (PBPK) modeling framework was employed to explore infliximab exposure following intravenous (5 mg/kg) and subcutaneous administration (encompassing the approved 120 mg flat-fixed dose as a switching option) in virtual adult and pediatric patients with inflammatory bowel disease (IBD). The PBPK model and corresponding simulations were conducted using the PK-Sim® software platform. The PBPK simulation indicated that a 120 mg subcutaneous flat-fixed dose might not be optimal for heavier adults with IBD, suggesting the need for infliximab dose escalation. For an older virtual pediatric patient (14 years old), subcutaneous administration of a 120 mg flat-fixed dose appears to be a feasible IBD treatment option. In the final exploration scenario, the model was extended to predict hypothetical subcutaneous infliximab doses in a virtual pediatric population (6-18 years old), stratified into three weight bands (20-30 kg, 30-45 kg, and 45-70 kg), that would yield post-switch trough concentrations of infliximab comparable to those seen in adults with the 120 mg flat-fixed subcutaneous dose. The PBPK-model-informed dose suggestions were 40 mg for the 20-30 kg band, 80 mg for the 30-45 kg band, and 120 mg for the 45-70 kg band. As demonstrated in this paper, the PBPK modeling framework can serve as a versatile tool in clinical pharmacology to investigate various clinical scenarios, such as exploring alternative dosing regimens and routes of administration, ultimately advancing IBD treatment across diverse (sub)populations of clinical interest.

Switching from intravenous to subcutaneous infliximab and vedolizumab in patients with inflammatory bowel disease: impact on trough levels, day hospital visits, and medical expenses

OBJECTIVE

Subcutaneous (SC) infliximab (IFX) and vedolizumab (VDZ) have recently become available. We aimed to examine the impact of switching from intravenous (IV) to SC IFX and VDZ in patients with inflammatory bowel disease (IBD) on costs, the day hospital burden, trough levels, and clinical outcomes.

METHODS

Our study comprised the cohort of IBD patients receiving IV IFX or VDZ at our hospital in 2022. We evaluated costs, day hospital visits, trough levels, biochemical markers, relapse rates, and self-report outcomes until Jun 30th 2023.

RESULTS

Of 114 patients, 18 continued IV therapy, 80 were switched to SC therapy, and 16 were inductions. Eighty-eight (90%) remained in steroid-free remission with no difference between the IV or SC groups. The mean IFX trough level changed from 8.2 ± 4.5 µg/ml to 14.5 ± 5.9 µg/ml, p < 0.001, and the VDZ trough level from 14.7 ± 7.1 mg/ml to 26.5 ± 13.8 mg/ml, p < 0.001. The average yearly costs of infusions and injections per patient were 2 580 € and 7 482 € for IFX and 15 990 € and 13 101 € for VDZ. The annual reduction of day hospital visits was 6,9 per patient.

CONCLUSIONS

IV and SC IFX and VDZ are equally effective in maintaining remission in IBD, but SC administration reduces day hospital visits and results in higher trough levels. SC VDZ is less and SC IFX more expensive than IV therapy. Further studies are needed to assess optimal dosing and separate trough levels for SC therapy.

Switching from Intravenous to Subcutaneous Biological Therapy for Inflammatory Bowel Disease Patients Remains a Challenge

Biological inflammatory bowel disease (IBD) medications, once limited to intravenous (IV) administration, can now be administered both via IV and subcutaneously (SC). This study investigates patient preferences, willingness to switch from IV to SC, and associated factors. A questionnaire covering demographics, disease-related inquiries, quality of life, and IBD medication preferences was distributed via email, the Israeli Crohn's Disease and Ulcerative Colitis Foundation, infusion centers, and clinics. From 454 IBD patients (median age: 42 years; 55.7% female), responses revealed a preference for SC every 8 weeks, which is comparable to daily oral dosing. Both options were significantly favored over IV every 8 weeks and SC every 2 weeks, with no statistically significant differences between the latter two. However, among patients who were experienced with both SC and IV administration, a clear preference for SC administration every 2 weeks over IV every 8 weeks surfaced. Among IV-treated patients, 54.5% resisted switching to SC. Key reasons for this included medical staff presence (57.7%), a fear of needles (46.4%), belief in infusion efficacy (37.1%), and longer intervals between infusions (36.1%). Findings suggest that transitioning from IV to SC treatment is challenging due to patient resistance, which is influenced by specific factors. Identifying and addressing these obstacles is crucial for optimizing IBD management.

Clinical use of biologics for Crohn's disease in adults: lessons learned from real-world studies

INTRODUCTION

The therapeutic armamentarium for managing Crohn's disease (CD) has expanded significantly in recent decades. Several biologics with three different mechanisms of action [anti-tumor necrosis factor (TNF)-α, anti-integrin α4β7, and anti-IL 12/23] are currently available to manage CD.

AREA COVERED

This narrative review aims to summarize the most significant efficacy and safety data on the use of infliximab (IFX), adalimumab (ADA), vedolizumab (VDZ) and ustekinumab (UST) for the treatment of CD obtained from studies conducted in the real world (RW), compared to the results of randomized clinical trials (RCTs).

EXPERT OPINION

RW studies reported that biologic agents included in this analysis have higher remission rates and lower adverse event rates than findings from RCTs for treating patients with CD. All biological agents have proven effective and safe in RW studies, even when using biosimilars or switching to subcutaneous administration of the molecules for which they are available. Finally, anti-TNF-α agents, particularly IFX, have a higher rate of adverse events (AEs) than VDZ and UST. Therefore, patients at higher risk of AEs may benefit from other biologics than anti-TNF-α. However, further long-term RW studies are needed to confirm these findings.