Cancer immunotherapy using immune-checkpoint blockade (ICB) has created a paradigm shift in the treatment of advanced-stage cancers. The promising antitumour activity of monoclonal antibodies targeting the immune-checkpoint proteins CTLA-4, PD-1, and PD-L1 led to regulatory approvals of these agents for the treatment of a variety of malignancies. Patients might experience clinical benefits from treatment with these agents, despite unconventional patterns of tumour response that can be misinterpreted as disease progression, warranting a new, specific approach to evaluate responses to immunotherapy. In addition, biomarkers that can predict responsiveness to ICB are being extensively investigated to further advance precision immunotherapy. Herein, we review the biological mechanisms underlying the unconventional response patterns associated with ICB, describe strategies for the objective assessments of such responses, and also highlight the ongoing efforts to identify biomarkers, in order to guide treatment with ICB. We provide state-of-the-art knowledge of immune-related response evaluations, identify unmet needs requiring further investigations, and propose future directions to maximize the benefits of ICB therapy.

使用免疫检查点封锁（ICB）的癌症免疫疗法已在晚期癌症的治疗中产生了范式转变。针对免疫检查点蛋白CTLA-4，PD-1和PD-L1的单克隆抗体的有希望的抗肿瘤活性，导致这些药物可用于多种恶性肿瘤的监管批准。尽管非常规的肿瘤反应模式可能被误解为疾病进展，但患者仍可能会从这些药物的治疗中获得临床收益，从而需要一种新的，特定的方法来评估对免疫疗法的反应。此外，正在广泛研究可以预测对ICB的反应性的生物标志物，以进一步推进精确免疫治疗。在这里，我们回顾了与ICB相关的非常规反应模式的生物学机制，描述对此类反应进行客观评估的策略，并强调识别生物标志物的持续努力，以指导用ICB进行治疗。我们提供有关免疫相关反应评估的最新知识，确定未满足的需求需要进一步研究，并提出未来的方向，以最大程度地发挥ICB治疗的益处。