Ipilimumab-dependent cell-mediated cytotoxicity of regulatory T cells ex vivo by nonclassical monocytes in melanoma patients

Enhancing immune responses with immune-modulatory monoclonal antibodies directed to inhibitory immune receptors is a promising modality in cancer therapy. Clinical efficacy has been demonstrated with antibodies blocking inhibitory immune checkpoints such as cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) or PD-1/PD-L1. Treatment with ipilimumab, a fully human CTLA-4-specific mAb, showed durable clinical efficacy in metastatic melanoma; its mechanism of action is, however, only partially understood. This is a study of 29 patients with advanced cutaneous melanoma treated with ipilimumab. We analyzed peripheral blood mononuclear cells (PBMCs) and matched melanoma metastases from 15 patients responding and 14…

• BS
  Bristol-Myers Squibb
• ST
  Stichting Tegen Kanker
• FL
  Fondation Leenaards
• CH
  Centre Hospitalier Universitaire Vaudois