This review focuses on immune checkpoint inhibitors – immunomodulatory agents that aim to relieve tumour-mediated immune-cell suppression. Immune checkpoint proteins can be expressed on the tumour-cell or immune-cell populations. Immune checkpoint proteins dampen the immune response by inactivating immune cells capable of tumour destruction. Blockade of immune checkpoints has shown impressive results in a range of solid cancers, particularly melanoma and non-small cell lung cancer. The potential benefit of this class of drugs is widespread across most cancer types and an unprecedented number of clinical studies are underway to examine the benefit of these agents. The aims of this review are to: provide an overview of the key early immune checkpoint inhibitor trials involving drugs targeting programmed cell death-1 (PD-1), programmed cell death ligand-1 (PD-L1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) in multiple disease types; provide an overview of emerging therapies aimed at these targets; and provide a detailed exploration of the status of immune checkpoint inhibitors in breast cancer.

这篇综述的重点是免疫检查点抑制剂——旨在缓解肿瘤介导的免疫细胞抑制的免疫调节剂。免疫检查点蛋白可以在肿瘤细胞或免疫细胞群上表达。免疫检查点蛋白通过灭活能够破坏肿瘤的免疫细胞来抑制免疫反应。免疫检查点的阻断在一系列实体癌中显示出令人印象深刻的结果，特别是黑色素瘤和非小细胞肺癌。这类药物的潜在益处在大多数癌症类型中普遍存在，并且正在进行数量空前的临床研究以检验这些药物的益处。本综述的目的是：概述涉及靶向程序性细胞死亡-1 (PD-1) 的药物的关键早期免疫检查点抑制剂试验，多种疾病类型中的程序性细胞死亡配体 1 (PD-L1) 和细胞毒性 T 淋巴细胞抗原 4 (CTLA-4)；概述针对这些目标的新兴疗法；并详细探讨免疫检查点抑制剂在乳腺癌中的地位。