鉴于40~50%的原发性中枢神经系统淋巴瘤（PCNSL）组织在9p24.1上表现出异常，免疫检查点抑制剂（ICI）可能对该疾病有效。为了明确ICIs在PCNSL中的作用，我们在全国范围内开展了一项研究对22例接受纳武单抗单药治疗的复发或难治性PCNSL患者进行回顾性分析。诊断时中位年龄为66岁，男女比例为1:1。患者在中位 3 线（范围，2 - 6）治疗后接受纳武单抗治疗，中位年龄为 67 岁（范围，37 - 82 岁）。 11 名患者 (50%) 对纳武利尤单抗之前的最后一次治疗耐药。中位随访时间为 22.3 个月（95% CI，13.1 - 31.5），9 名患者（41%）出现客观缓解（6 名完全缓解，3 名部分缓解），中位缓解持续时间为 20.9 个月（ 95% CI，1.7 - 40.0）。中位无进展生存期和总生存期分别为 2.1 个月（95% CI，0.2 - 4.0）和 18.9 个月（95% CI，5.0 - 32.8）。纳武单抗通常具有良好的耐受性，因为没有患者需要减少剂量，只有 2 名患者需要延迟治疗。我们的研究表明，纳武单抗可能是 RR PCNSL 的合理选择，具有持久的反应。

Given that 40~50% of primary central nervous system lymphoma (PCNSL) tissues exhibit aberrancy on 9p24.1, immune-checkpoint inhibitors (ICI) may work for the disease.To define the role of ICIs in PCNSL, we carried out a nationwide retrospect analysis for 22 patients who had been treated with nivolumab monotherapy for relapsed or refractory PCNSL.The median age at diagnosis was 66, and male: female ratio was 1:1. Patients received nivolumab after a median of 3 lines (range, 2 - 6) of therapy and at the median age of 67 (range, 37 - 82). Eleven patients (50%) were refractory to the last treatment prior to nivolumab. With a median follow-up duration of 22.3 months (95% CI, 13.1 - 31.5), nine patients (41%) had an objective response (6 complete responses, 3 partial responses), and the median duration of response was 20.9 months (95% CI, 1.7 - 40.0). The median progression-free survival and overall survival were 2.1 months (95% CI, 0.2 - 4.0) and 18.9 months (95% CI, 5.0 - 32.8), respectively. Nivolumab was generally well-tolerated as no patients required dose reduction and only 2 patients required delay of treatment.Our study suggests that nivolumab can be a reasonable option with the durable response for RR PCNSL.