Peripheral immune features associated with severe immune-related adverse events and clinical benefit in checkpoint inhibitor-treated melanoma

Poster Highlights

• In this study, we used mass cytometry to characterize 30+ immune cell subsets before and during presentation of severe irAEs (grade 2+ that required clinical intervention) to identify immune features associated with irAE presentation.

• Using unsupervised clustering and manual gating, we found that patients with severe irAE have 1.5x - 2x fewer TIGIT+ Treg and CD16+ NK cells at baseline and 2x-3x more activated CD38 and CD39+ central memory T cells during irAE presentation.

• Some of these immune features, such as differences in TIGIT+ Treg cells were driven by individual categories of irAE, while others were not.

• Interestingly, patients with severe irAE were 2x more likely to benefit from immunotherapy, and clinical benefit was associated with similar immune features as severe irAE.