Phillips Therese, Simmons Pauline, Inzunza Hector D, Cogswell John, Novotny James, Taylor Clive, Zhang Xiaoling
*Dako North America Inc., Carpinteria ‡Keck School of Medicine of the University of Southern California, Los Angeles, CA †Bristol-Myers Squibb Inc., Princeton, NJ.
Appl Immunohistochem Mol Morphol. 2015 Sep;23(8):541-9. doi: 10.1097/PAI.0000000000000256.
Nivolumab, a fully human IgG4 programmed death 1 (PD-1) immune checkpoint inhibitor antibody, developed by Bristol-Myers Squibb Inc., has activity across non-small cell lung cancer (NSCLC) histologies and is Food and Drug Administration approved for treatment of metastatic squamous NSCLC with progression on or after platinum-based chemotherapy. PD-L1 has been investigated as a potential biomarker to predict clinical response to nivolumab in clinical settings. We report an automated PD-L1 immunohistochemistry (IHC) assay, which was developed to detect cell surface PD-L1 in formalin-fixed paraffin-embedded human tumor tissue specimens using Dako's Autostainer Link 48. The primary antibody for this assay is a rabbit monoclonal anti-human PD-L1 antibody, clone 28-8. The specificity of 28-8 for PD-L1 was demonstrated by antigen competition and genetic deletion of PD-L1 in tumor cell lines. The specificity of the PD-L1 IHC assay was further evaluated in a collection of 30 normal human tissues. The PD-L1 IHC assay was optimized for high sensitivity and precision in routine application. A pathology scoring and interpretation method specific to nivolumab clinical studies was adopted for the assay. The analytical performance of the assay was validated for application in the determination of PD-L1 status in human NSCLC specimens. The clinical application of the assay and scoring method was further validated in 3 Clinical Laboratory Improvement Amendments certified labs. The assay is currently being investigated in a variety of clinical studies for use as an in vitro diagnostic to select and stratify patients for treatment with the anti-PD-1 therapeutic antibody, nivolumab.
纳武单抗是百时美施贵宝公司研发的一种全人源IgG4程序性死亡1（PD-1）免疫检查点抑制剂抗体，对非小细胞肺癌（NSCLC）的各种组织学类型均有活性，且已获美国食品药品监督管理局批准，用于治疗在铂类化疗期间或之后病情进展的转移性鳞状NSCLC。在临床环境中，PD-L1已被作为预测纳武单抗临床反应的潜在生物标志物进行研究。我们报告了一种自动化的PD-L1免疫组织化学（IHC）检测方法，该方法旨在使用达科公司的Autostainer Link 48检测福尔马林固定石蜡包埋的人类肿瘤组织标本中的细胞表面PD-L1。该检测方法的一抗是兔单克隆抗人PD-L1抗体，克隆号为28-8。通过抗原竞争和肿瘤细胞系中PD-L1的基因缺失证明了28-8对PD-L1的特异性。在30份正常人体组织样本中进一步评估了PD-L1 IHC检测方法的特异性。该PD-L1 IHC检测方法针对常规应用进行了优化，以实现高灵敏度和高精度。该检测采用了一种纳武单抗临床研究特有的病理评分和解读方法。该检测方法的分析性能已在用于确定人类NSCLC标本中PD-L1状态的应用中得到验证。该检测方法和评分方法的临床应用在3家符合临床实验室改进修正案认证的实验室中进一步得到验证。目前，该检测方法正在多项临床研究中进行研究，用作体外诊断方法，以选择和分层适合使用抗PD-1治疗性抗体纳武单抗进行治疗的患者。
