Depletion of Effector Regulatory T Cells Associates with Major Response to Induction Dual Immune Checkpoint Blockade.

ABSTRACT: In a phase II trial, patients with local-regionally advanced human papillomavirus-positive oropharyngeal carcinoma (n = 35) received ipilimumab (anti-CTLA4) and nivolumab (anti-PD-1) as induction immunotherapy and concurrently with radiotherapy (NCT03799445). Coprimary endpoints included 6-month complete metabolic response rate (94%) and 2-year progression-free survival (84%). Induction yielded a 46% major histopathologic response rate. Single-cell profiling revealed responders had higher baseline intratumoral CD8+ T cells with a tumor-reactive, tissue-resident memory (TRM) phenotype and a treatment-related decrease in effector regulatory T (eTreg) cells. The eTreg decrease correlated with CD8+ T-cell clonotype transitioning from TRM to effector memory and IFNG+ effector cells. In nonrespo

SUBMITTER: Jiang X 

PROVIDER: S-EPMC12319410 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature