Programmed cell death 1 (PD-1) signal receptor blockade has revolutionized the field of cancer therapy. Despite their considerable potential for treating certain cancers, drugs targeting PD-1 still present two main drawbacks: the substantial number of unresponsive patients and/or patients showing recurrences, and side effects associated with the autoimmune response. These drawbacks highlight the need for further investigation of the mechanisms underlying the therapeutic effects, as well as the need to develop novel biomarkers to predict the lack of treatment response and to monitor potential adverse events. Combination therapy is a promising approach to improve the efficacy of PD-1 blockade therapy. Considering the increasing number of patients with cancer worldwide, solving the above issues is central to the field of cancer immunotherapy. In this review, we discuss these issues and clinical perspectives associated with PD-1 blockade cancer immunotherapy.

中文翻译：

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PD-1阻断癌症免疫治疗的当前问题和观点。

程序性细胞死亡1（PD-1）信号受体阻滞彻底改变了癌症治疗领域。尽管靶向PD-1的药物具有治疗某些癌症的巨大潜力，但仍存在两个主要缺点：无反应的患者和/或表现出复发的患者数量众多，以及与自身免疫反应相关的副作用。这些缺点突出了需要进一步研究治疗作用的潜在机制，以及开发新的生物标志物以预测缺乏治疗反应并监测潜在不良事件的需要。联合疗法是提高PD-1阻断疗法疗效的一种有前途的方法。考虑到全球范围内癌症患者数量的增加，解决上述问题对于癌症免疫治疗领域至关重要。