99P - Real-world management of ir-colitis, a Danish 10-year cohort study

Background

Immune checkpoint inhibitors (CPI) induced diarrhoea and colitis (ir-colitis) are common immune-related adverse events. Ir-colitis management guidelines are based on expert consensus. This retrospective study presents real-world data on melanoma patients with ir-colitis requiring medical intervention. The objective was to describe treatment patterns, hypothesising that glucocorticoid (GC) use exceeds guidelines and that biologic treatment (BIOx) initiation is often delayed.

Methods

Melanoma patients treated with CPI (anti-PD-1 and/or anti-CTLA4) in Southern Denmark (2013–2023) were identified from the Danish metastatic melanoma database. A validated AI language model was employed for identification of ir-colitis patients. Patient and treatment characteristics were analysed based on CPI regimen, CTCAE grade, sex, age, GC use, BIOx, and GC tapering failure.

Results

In 85 included patients (120 expected in the final cohort), predominantly female (n=47), the median (Mdn) age was 69 years (SD = 13.5), with 52% experiencing grade IV ir-colitis. Anti-CTLA4 regimens were the most common triggers, with 39% receiving monotherapy and 29% combination therapy. Forty-three patients achieved remission on GC alone, with Mdn prednisolone (PRED) dose of 1025 mg (IQR 600-1638). Among BIOx patients (n=38), the Mdn PRED dose was 2991 mg (IQR 1965-4403), with a Mdn interval of 17 days from GC initiation to BIOx. Infliximab was used in all BIOx patients; 11 required a second dose, and three needed a third. Mdn duration from GC initiation to complete tapering was 35 days (IQR 22-43) without BIOx and 65 days (IQR 49-93) with BIOx. Mdn duration from BIOx initiation to complete tapering was 45 days (IQR 29-67). Forty-two patients experienced failure during tapering, with Mdn GC usage of 2650 mg (IQR 1543-4403); among BIOx patients (n=24), Mdn GC usage was 3354 mg (IQR 2176-5027). In addition, peak GC dose and ir-colitis’s impact on survival compared with matched controls will be presented.

Conclusions

BIOx was required in 45% of cases, highlighting the need for optimised ir-colitis management by addressing excessive GC use and delayed initiation of BIOx. Further prospective studies are warranted, awaiting results from ongoing randomized clinical trials (e.g. NCT05947669).

Editorial acknowledgement

AI-assisted technology (ChatGPT-4) was used to improve the readability of the abstract at a final stage of abstract editing. After using these services, the authors reviewed and edited the content as needed and take full responsibility for the content of the abstract.

Legal entity responsible for the study

Department of Oncology, Odense University Hospital.

Funding

The research salary of SK(main author) were granted as part of his PhD. Grants were obtained by the Odense University Hospitals PhD fund and PhD fund of the Region of Southern Denmark. The Danish metastatic melanoma database is supported by Bristol Myers Squibb, Roche, Novartis, MSD, and Pierre Fabre. The funding bodies did not have any other role in the study.

Disclosure

C.H. Ruhlmann: Financial Interests, Personal, Invited Speaker: Bristol Myers Squibb, Helsinn Healthcare, MSD, Pharmanovia; Financial Interests, Personal, Other, Consultant: Astellas Pharma; Financial Interests, Institutional, Coordinating PI, Funding for a clinical trial; Helsinn Healthcare, Novo Nordisk Foundation. All other authors have declared no conflicts of interest.