P0913 - How Many Doses of Infliximab Should Be Used in Immune Checkpoint Inhibitor-Induced Colitis? – A Retrospective Study

Rupayan Kundu, MD¹, Arjun Chatterjee, MD¹, Emily Zabor, ¹, James Isaacs, MD¹, Thach-Giao Truong, MD¹, Joseph Sleiman, MD², Pauline Funchain, MD³, Jessica Philpott, MD, PhD¹, Lucy Kennedy, MD^1
1Cleveland Clinic Foundation, Cleveland, OH; ²University of Pittsburgh Medical Center, Pittsburgh, PA; ³Stanford University School of Medicine, Stanford, CA

Introduction: Immune checkpoint inhibitor (ICI)-related colitis (ir-colitis) is a common immune-related adverse event (irAE). For patients with steroid-refractory ir-colitis, anti-tumor necrosis factor agents such as infliximab are recommended. However, clinicians face significant challenges in determining the optimal number of infliximab doses needed to manage ir-colitis while maintaining anti-tumor efficacy of ICI. It is not known whether administering maintenance infliximab concurrently with ICI worsens cancer outcomes. In this study, we investigated cancer progression in pts who received > 3 doses of infliximab for steroid-refractory ir colitis compared to those who received ≤3 doses.

Methods: In this retrospective, single-center study, patients were categorized into 2 groups based on number of infliximab doses received: ≤3 doses and >3 doses. We calculated time to progression (TTP) (figure 1A), overall survival (OS) (figure 1B), and progression-free survival (PFS) (figure 1C) using a landmark analysis. The first three induction doses of infliximab were administered at 0, 2, and 6 weeks, followed by maintenance doses every 8 weeks. Consequently, we used a landmark time of 14 weeks for this analysis. Patients who had progressive disease at the onset of infliximab treatment were excluded from the TTP and PFS analyses.

Results: Of 29 pts, majority were white males with melanoma, and stage IV disease [Table 1]. 48.3% (n=14) of pts received >3 doses of infliximab with a median number of 6 doses (IQR: 4-7) [Table 1]. The median follow-up time among those without cancer progression was 703.5 days (IQR: 529.5 - 1190.5), still alive was 709 days (IQR: 371 – 1204), and still alive without progression, was 676 days (IQR: 481 - 1202). There were no significant differences in age, sex, ethnicity, cancer type, or cancer stage between the two groups. No significant difference in TTP, PFS, or OS were observed according to the number of infliximab cycles in the landmark analysis. [Figure 1]

Discussion: There was no association between receipt of > 3 doses of infliximab and worsened cancer outcomes, including PFS and OS, in our series, failing to detect cancer risk with longer term infliximab therapy. However, given the limitations of our study, including small sample size, single-center analysis, retrospective design, and lack of diversity, further prospective studies are warranted to confirm these findings and optimize infliximab dosing strategies.



Disclosures:


Rupayan Kundu, MD¹, Arjun Chatterjee, MD¹, Emily Zabor, ¹, James Isaacs, MD¹, Thach-Giao Truong, MD¹, Joseph Sleiman, MD², Pauline Funchain, MD³, Jessica Philpott, MD, PhD¹, Lucy Kennedy, MD¹. P0913 - How Many Doses of Infliximab Should Be Used in Immune Checkpoint Inhibitor-Induced Colitis? – A Retrospective Study, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.