e14588 Background: The PD-L1 IHC 28-8 pharmDx assay has been developed for use in detection of PD-L1 protein in formalin-fixed, paraffin-embedded (FFPE) non-squamous NSCLC and melanoma tissues for associated treatment effect with nivolumab. Validation of the assay for measuring PD-L1 expression level in human squamous cell carcinoma of the head and neck (SCCHN) FFPE sections has been conducted and results are described. Methods: Visualization of the PD-L1 IHC 28-8 pharmDx assay is based on the EnVision FLEX IHC technology. As described in the Instructions For Use, antigen retrieval was performed using the Dako PT Link, and the automated staining was conducted with Autostainer Link 48. The assay performance was validated on commercially procured FFPE SCCHN specimens. Results: Assessment of assay sensitivity to PD-L1 expression was measured on 236 unique specimens originating from squamous cell carcinoma of the tongue, tonsil, nasopharynx, oropharynx, hypopharynx, and larynx. The study demonstrated PD-L1 positive staining across a range of 0-95% positive tumor cells and 0 to 3+ staining intensity. Among these tested specimens, 44% of specimens had PD-L1 expression levels ≥1%. Assay robustness was validated by assessing critical parameters such as target retrieval solution pH, target retrieval solution temperature, target retrieval time, and cut section thickness. Assay reproducibility was evaluated in a study at three external sites. Reproducibility of intra-site, inter-day, and inter-site agreement was assessed in addition to inter- and intra-observer agreement. Assay robustness and reproducibility demonstrated agreement estimates above 85% with values for lower bound 95% confidence intervals calculated above 85%. Conclusions: These studies demonstrate that the PD-L1 IHC 28-8 pharmDx assay is reproducible and robust when used for automated detection of PD-L1 protein in FFPE human SCCHN specimens using Autostainer Link 48.
In acute rheumatic heart disease, lysis of cardiac muscle fibres with or without retention of sarcolemma is found to be the most damaging feature in many cases. In deeper myocardium the cellular lysis often forms anastomosing clefts or sinus-like spaces between surviving muscle bundles and in the outer portion of myocardium cellular lysis may leave the sarcolemma more or less intact. From lysing cardiac muscle fibres there arise dedifferentiated cells with remarkable potentiality for regeneration. For the origin of these dedifferentiated cells, which are often indistinguishable from lymphocytes, no mitosis is seen in cardiac muscle cells. The successive stages of development of muscle cell from these dedifferentiated cells within the remaining or newly formed sarcolemma have been observed in this study. This study infers that the increased number of fibrous septa, when seen, denotes the tracks of previous muscle degeneration and subsequent replacement of it with incomplete muscle regeneration and fibrous tissue formation. In an area of muscle lysis the origin of Aschoff bodies from these dedifferentiated cells has been followed. Ashoff bodies arising in this was behave as an abortive and atypical growth of muscle fibres in a nodular fashion specific to rheumatic fever.
e14585 Background: PD-L1 IHC 28-8 pharmDx is a qualitative assay developed by Agilent Technologies for the Autostainer Link 48 platform and is based on EnVision FLEX visualization technology and monoclonal rabbit anti-PD-L1, clone 28-8 antibody. The assay has been co-developed with the immunotherapeutic agent nivolumab; initially as an aid in assessing PD-L1 expression in non-squamous non-small cell lung cancer (NSCLC) and melanoma patients. Here we describe the efforts to validate this assay for urothelial carcinoma (UC). Methods: IHC staining was performed on Autostainer Link 48 platform using an automated staining protocol stated per the assay’s instruction for use (IFU). Specimens were coverslipped and interpreted for % PD-L1 positive tumor cells. The assay was analytically validated on commercially acquired formalin-fixed, paraffin-embedded (FFPE) human UC invasive tumor specimens at ≥1% and ≥5% PD-L1 positive tumor cells expression levels. Results: A wide range of % PD-L1 positive tumor cells at all staining intensity levels have been detected. Assay in-house precision was validated for inter-operator, inter-instrument, inter-day, inter-run and intra-run as well as inter-observer and intra-observer agreement. Robustness studies evaluated the assay under multiple conditions for target retrieval pH, temperature and incubation time, slide type as well as tissue section thickness. Assay reproducibility was evaluated at three external sites by testing samples for intra-site/inter-day and inter-site agreement measures. Specimens were also evaluated by an observer at each site, with three reads for each observer to assess intra-observer and inter-observer agreement. All validation studies demonstrated agreement estimates above 85% with values for lower bound 95% confidence intervals calculated above 84%. Conclusions: Results of all conducted studies show high robustness and reproducibility of the assay on UC.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.