Abstract 5650
Background
Up to 44% of patients receiving combination ipilimumab and nivolumab develop checkpoint-inhibitor-(CI) colitis, however its molecular pathogenesis is poorly understood. We aimed to characterise peripheral blood and gut mononuclear cells (PBMC; GMNC) in patients with CI-colitis and controls to gain insights into disease aetiology. We were particularly interested in activated, memory, gut-homing CD8+ T-cells and also the innate-like mucosal-associated invariant T (MAIT) cells that play important roles in mucosal immunity.
Methods
In Cohort I PBMC from patients with CI-colitis (N = 9) were compared with those from patients who received CI with no adverse-events (CI-controls; N = 11), patients with active ulcerative colitis (UC; N = 6) and Healthy Volunteers (N = 16). PBMC findings were tested in a second cohort (Cohort II; IN-Colitis N = 15; IN-NAE=9). GMNC were isolated in Cohort III (IN-colitis N = 5; IN-controls N = 5; UC N = 6; Healthy Volunteers N = 6). Flow-cytometric analysis was used throughout.
Results
CI-colitis patients had low circulating MAIT cells compared with CI-controls at baseline in Cohort I. Low levels of circulating MAIT cells in both CI-colitis and CI-controls (compared to Healthy Volunteers) were found in Cohort II. CI-treated patients had high levels of activated-memory T-cells in peripheral blood (CD8 + >CD4+) that included a gut-homing population, regardless of the development of colitis. However, activation of circulating MAIT cells was not evident. In gut tissue there was elevation of activated, granzyme-B+ MAIT cells in CI-colitis compared with CI-controls. CI-colitis was characterised by an activated-memory CD8+ lymphocytosis.
Conclusions
Melanoma patients can have low baseline circulating MAIT cells. In one cohort this associated with CI-colitis. In tissue, activated MAIT cells were elevated in CI-colitis. Further work is needed to determine which immune populations are useful for the prediction and prognostication of CI-colitis, and if MAIT cells contribute to tissue damage or repair.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Celgene.
Disclosure
S.C. Sasson: Research grant / Funding (institution): Celgene. V.T.F. Cheung: Speaker Bureau / Expert testimony: Janssen. G.V. Long: Advisory / Consultancy: Aduro; Advisory / Consultancy: Amgen; Advisory / Consultancy: BMS; Advisory / Consultancy: Merck MSD; Advisory / Consultancy: Mass-Array; Advisory / Consultancy: Novartis; Advisory / Consultancy: Pierre Fabre; Advisory / Consultancy: Roche. M.R. Middleton: Advisory / Consultancy: Amgen; Advisory / Consultancy: AstraZeneca; Advisory / Consultancy: BMS; Advisory / Consultancy: Eisai; Advisory / Consultancy: Lilli; Advisory / Consultancy: Merck; Advisory / Consultancy: Millenium; Advisory / Consultancy: Novartis; Advisory / Consultancy: Physiomics; Advisory / Consultancy: Rignotec; Advisory / Consultancy: Roche. O. Brain: Speaker Bureau / Expert testimony: BMS; Research grant / Funding (institution): Celgene. All other authors have declared no conflicts of interest.
Resources from the same session
1084 - Dissociated responses in patients with metastatic solid tumors treated with immunotherapy
Presenter: Pauline Vaflard
Session: Poster Display session 3
Resources:
Abstract
4600 - Patterns and outcomes related to rapid progressive disease in a cohort of advanced solid tumors treated with immune checkpoint inhibitors (ICIs).
Presenter: Lucio Ghiglione
Session: Poster Display session 3
Resources:
Abstract
3547 - Real World Outcomes of Immune-Related Adverse Events (irAEs) among Patients Receiving Immune Checkpoint Inhibitors (ICIs) in Hospital Settings
Presenter: Saby George
Session: Poster Display session 3
Resources:
Abstract
1124 - Sex-based heterogeneity of efficacy of anticancer immunotherapy
Presenter: Fabio Conforti
Session: Poster Display session 3
Resources:
Abstract
4133 - Comparative efficacy and safety of PD-1/PD-L1 inhibitors for patients with solid tumors: a systematic review and Bayesian network meta-analysis
Presenter: Qingyuan Huang
Session: Poster Display session 3
Resources:
Abstract
2548 - Excess weight and efficacy of anti-PD-1 antibodies in advanced cancer patients
Presenter: Jacobo Rogado
Session: Poster Display session 3
Resources:
Abstract
2228 - Safety and efficacy of anti-PD-1 inhibitor ABBV-181 in lung and head and neck carcinoma
Presenter: Antoine Italiano
Session: Poster Display session 3
Resources:
Abstract
2333 - Efficacy and safety of immune checkpoint inhibitors (ICIs) for treatment of advanced solid tumours in octogenarian patients
Presenter: Soraya Mebarki
Session: Poster Display session 3
Resources:
Abstract
4847 - Association of programmed cell death 1 (PD-1) inhibitor therapy with overall survival (OS) in stage IV melanoma treated with targeted therapies
Presenter: Aracelis Torres
Session: Poster Display session 3
Resources:
Abstract
2215 - Clinical outcomes of immune checkpoint inhibitors in older and younger patients with advanced solid tumours in a real-life setting
Presenter: Pauline Corbaux
Session: Poster Display session 3
Resources:
Abstract