P0201 - Prevalence and Treatment of Immune Checkpoint Inhibitor (ICI) Colitis in Patients with Gastrointestinal Malignancy: A Multi-Center Network Study

Nikolas Naleid, MD, PharmD¹, Jaime A. Perez, PhD², Vibhu Chittajallu, MD¹, Bianca Islam, MD, PhD¹, Fangyuan Jin-Dominguez, MD³, Ahmed Nadeem, MD⁴, Preetika Sinh, MD⁵, Jeffry Katz, MD⁶, Vu Nguyen, MD⁶, Miguel Regueiro, MD⁷, Gregory Cooper, MD⁶, Emad Mansoor, MD^1
1Case Western Reserve University / University Hospitals, Cleveland, OH; ²University Hospitals Clinical Research Center, Cleveland, OH; ³Case Western Reserve / University Hospitals Cleveland Medical Center, Cleveland, OH; ⁴Cleveland Clinic, Cleveland, OH; ⁵Medical College of Wisconsin, Milwaukee, WI; ⁶Case Western Reserve/UHCMC, Cleveland, OH; ⁷Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH

Introduction: Immune checkpoint inhibitor (ICI) colitis is a commonly reported gastrointestinal immune-related adverse event. This study aimed to determine the prevalence of ICI colitis between ICI regimens and to compare the treatment regimens for ICI colitis in patients with an underlying gastrointestinal malignancy.

Methods: A retrospective cohort study was conducted utilizing TriNetX, a health research network with data sourced from 80 health care organizations within the United States. The cohort included patients on PD-1 inhibitors (pembrolizumab, nivolumab, cemiplimab), PD-L1 inhibitors (durvalumab, atezolizumab, avelumab), and combination PD-1/CTLA-4 inhibitors (nivolumab/ipilimumab) with a history of a gastrointestinal malignancy (ICD-10: C15-C26) who developed ICI colitis within one year of initiation of ICI. Patients with Crohn's disease or Ulcerative colitis were excluded from the analysis. The 3-month outcomes of new methylprednisolone, prednisone, infliximab, and vedolizumab utilization for ICI colitis between patients on PD-1 inhibitors, PD-L1 inhibitors, and combination PD-1/CTLA-4 inhibitors were compared after 1:1 propensity score matching for demographics, co-morbid conditions, and medication use. Outcomes were reported as odds ratios with 95% confidence intervals.

Results: Among patients with a history of GI malignancy, the prevalence of ICI colitis was 7.9% for patients on PD-1 inhibitors, 6.2% for patients on PD-L1 inhibitors, and 8.6% for patients on combination PD-1/CTLA-4 inhibitors.




Patients with ICI colitis from PD-1 inhibitors vs. combination PD-1/CTLA-4 inhibitors similarly required biologics (Vedolizumab (1.7% vs. 1.7%) [OR 1, 95% CI 0.41-2.42], Infliximab (2.6% vs. 4.2%) [OR 0.62, 0.32-1.19]) and steroids (Prednisone (20.1% vs. 21.5%) [OR 0.92, 0.63-1.34], Methylprednisolone (12.1% vs. 13.7%) [ OR 0.86, 0.55-1.34]).



Patients with ICI colitis from PD-L1 inhibitors vs. combination PD-1/CTLA-4 inhibitors similarly required biologics (Vedolizumab (5.5% vs. 5.5%) [OR 1, 0.41- 2.46], Infliximab (5.5% vs. 5.6%) [OR 0.99, 0.4-2.45]) and steroids (Prednisone (16.4% vs. 25.5%) [OR 0.57, 0.29-1.12], Methylprednisolone (14.3% vs. 14.8%) [OR 0.96, 0.45-2.06]).

Discussion: The prevalence of ICI colitis in patients with an underlying GI malignancy ranged from 6-9%, depending on the ICI regimen. Furthermore, these patients were similarly treated with steroids and biologics regardless of the ICI regimen.



Disclosures:


Nikolas Naleid, MD, PharmD¹, Jaime A. Perez, PhD², Vibhu Chittajallu, MD¹, Bianca Islam, MD, PhD¹, Fangyuan Jin-Dominguez, MD³, Ahmed Nadeem, MD⁴, Preetika Sinh, MD⁵, Jeffry Katz, MD⁶, Vu Nguyen, MD⁶, Miguel Regueiro, MD⁷, Gregory Cooper, MD⁶, Emad Mansoor, MD¹. P0201 - Prevalence and Treatment of Immune Checkpoint Inhibitor (ICI) Colitis in Patients with Gastrointestinal Malignancy: A Multi-Center Network Study, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.