C0377 - Ustekinumab Therapeutic Drug Monitoring in Inflammatory Bowel Disease

Adam A. Saleh, BS¹, Rachel Stading, BS², Natalia Miroballi, BS², Kerri Glassner, DO³, Bincy Abraham, MD, MS, FACG^3
1Engineering Medicine at Texas A&M Health Science Center Medical School, Houston, TX; ²Texas A&M Health Science Center Medical School, Houston, TX; ³Houston Methodist Academic Institute, Houston, TX

Introduction: In the setting of inflammatory bowel disease (IBD), therapeutic drug monitoring (TDM) is a commonly used clinical tool to guide anti-TNF therapy; however, the use of TDM for ustekinumab (UST) has yet to be fully defined. The goal of this study is to analyze possible correlations between UST drug levels and patient characteristics, disease activity, and clinical outcomes in a population of both Crohn’s disease (CD) and ulcerative colitis (UC) patients.

Methods: A retrospective cohort study was performed for IBD patients who had UST trough levels drawn at maintenance dosing. In addition to trough levels, other data collected include patient demographics, such as age, gender, BMI, therapy management, such as dosing schedule, concurrent drug therapies, and previously failed biologics, and treatment outcomes, such as laboratory biomarkers, clinical scores, and endoscopy scores.

Results: The population of 177 IBD patients had an average UST trough level of 4.742 µg/mL without antibody development in any patient. Higher frequency dosing schedules (i.e. Q4, Q6) were significantly associated (p< 0.001) with increased UST trough levels compared to standard (Q8 week) maintenance dosing. Patient demographics, including age, gender, ethnicity, and BMI did not correlate with trough levels. Furthermore, disease duration, subtype, location, and phenotype did not show a significant difference in UST trough levels. Naiveté to anti-TNFs correlated with higher UST titer levels (p=0.048) with 67% adequate UST titer for anti-TNF naïve patients vs 48% for those with previous exposure to anti-TNFs. A higher erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were significantly related to lower UST titer levels (p=0.002 and p=0.005, respectively). HBI for CD and Mayo Score and UCAI for UC failed to show significance to titer levels. Mayo and Rutgeerts endoscopic scores did not correlate with titer levels, but lower SES-CD correlated with adequate titer levels (p=0.018).

Discussion: Furthermore, prior anti-TNF exposure was associated with lower UST levels, which suggests a possible advantage of prescribing UST for biologically naïve patients. Overall, higher UST drug levels correlated with lower SES-CD scores and ESR and CRP levels, indicating decreased inflammation. Based on these findings, therapeutic drug monitoring of UST trough levels and corresponding dosing schedule adjustments to reach target levels may ensure more adequate response from UST therapy.



Disclosures:


Adam A. Saleh, BS¹, Rachel Stading, BS², Natalia Miroballi, BS², Kerri Glassner, DO³, Bincy Abraham, MD, MS, FACG³. C0377 - Ustekinumab Therapeutic Drug Monitoring in Inflammatory Bowel Disease, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.