Therapeutic Drug Monitoring (TDM) of Infliximab Is Associated with Lower Biologic Switch & Expenditures Compared to No-TDM Cohort of IBD Patients Based on 12 to 48-Month Real-World Outcomes from a US Community GI Practice

OBJECTIVES: Infliximab (IFX) is an anti-TNF biologic used in inflammatory bowel disease (IBD). First biologic is best so avoiding treatment failure is important. However, up to 40% experience primary non-response (PNR) and 50% secondary loss of response (SLR) in the first year, with most frequent cause being suboptimal dosing leading to subtherapeutic drug levels. Therapeutic drug monitoring (TDM) improves outcomes, and detecting antibodies which can neutralize anti-TNFs and/or clears it from the patient’s system, is useful in identifying PNR or avoiding SLR which may necessitate biologic switching.

Describe the real-world biologic switching and expenditures (+Sankey), between IFX dose-optimized patients using Anser® TDM versus no-TDM control in community-based gastroenterology practice.

METHODS: De-identified patient charts (EMR) from a US community gastroenterology practice were analyzed for patients (ages 8-89) treated with IFX from 2016 to 2022. Matching records to Prometheus Laboratories test results were tokenized. Two cohorts were structured, TDM and no-TDM. Groups were matched by propensity score, baseline disease, demographics, and comorbidities. Biologic switching (IFX discontinuation and start of different biologic), corresponding mean biologic expenditures (MBE$) (aggregate reference wholesale acquisition cost per EMR data for specific duration), and Sankey were accessible via Lynx.MD. Analysis was conducted, stratifying patients, all or anti-TNF naïve (TNF-N), for different time-periods. Statistics was by chi-squared (biologic switch) and two sample t-test (expenditures).

RESULTS: Biologic switch rates were significantly lower for TDM versus no-TDM for all time-periods in all patients 17%/25% (8%)@12-months, 36%/24% (12%)@24-months, 48%/30% (18%)@36-months, 54%/35% (19%)@48-months; in TNF-N, all durations except 12-months 20%/14% (6%)@12-months, 20%/31% (11%)@24-months, 24%/42% (17%)@36-months, 47%/30% (17%)@48-months. MBE$ were lower because of lower switch rates for TDM for all time points in all and TNF-N patients (significant for 36- & 48-months).

CONCLUSIONS: Anser® TDM was associated with significantly lower biologic switches and mean biologic aggregate expenditures versus no-TDM matched cohort in the real-world setting.