In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 35, No. 15_suppl ( 2017-05-20), p. e23108-e23108
Abstract:
e23108 Background: Immunotherapy is rapidly emerging as one of the most promising therapeutic options in clinical oncology. However, not all patients will respond to immune-oncology drugs and diagnostic assays are urgently needed to identify biomarkers that predict response to these therapies. We developed an assay that utilizes next generation sequencing data to simultaneously determine different types of somatic changes in tumors. The assay was designed, in part, to facilitate identification of cancer patients most likely to respond to immunotherapies by detecting 1) CD274 (PD-L1) copy number alterations, 2) viral infections (HPV16/18 and EBV), 3) microsatellite instability (MSI), and 4) tumor mutation burden. Methods: We developed a 435-gene panel assay (CancerPlex) with the goal of identifying all the genomic changes that inform treatment decisions with the highest possible accuracy. We thoroughly evaluated the performance of the assay using reference samples that represent all classes of genetic variation, including SNPs, indels, copy number changes, rearrangements, HPV/EBV infection and MSI. FFPE clinical samples were also evaluated to assess the ability of the assay to detect genetic variation in complex, heterogeneous tumors. Results: The assay has excellent performance, with a mean sensitivity of 99.4% and specificity of 99.9% for detecting somatic mutations with an allele fraction as low as 10%. The assay identified the MSI status of colorectal tumors with the same sensitivity as immunohistochemistry but with greater sensitivity than PCR. We also showed that calculating tumor mutation burden using the 435-gene panel predicts response to pembrolizumab as effectively as using whole exome sequencing. Among 892 patients across all tumor types, 6.8% were identified as candidates for immunotherapy based upon high tumor mutation burden and/or MSI status. Conclusions: The capacity of the 435-gene panel to determine all of the critical genetic changes, tumor mutation burden, MSI status, CD274 (PD-L1) CNVs, and HPV/EBV status has important ramifications for patient treatment strategies, including identification of patients who are more likely to benefit from immune checkpoint inhibitor therapies.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/JCO.2017.35.15_suppl.e23108
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2017
detail.hit.zdb_id:
2005181-5
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