Development of an Immunofluorescent AR-V7 Circulating Tumor Cell Assay - A Blood-based Test for Men with Metastatic Prostate Cancer

Overview

Journal J Circ Biomark

Date 2021 Mar 15

PMID 33717359

Citations 5

Authors

David Lu

Rachel Krupa

Melissa Harvey

Ryon P Graf

Nicole Schreiber

Ethan Barnett

Emily Carbone

Adam Jendrisak

Audrey Gill

Sarah Orr

Howard I Scher

Joseph D Schonhoft

Affiliations

Soon will be listed here.

Abstract

Introduction: Here we describe the development of a protein immunofluorescent assay for the detection of nuclear-localized androgen receptor variant 7 (AR-V7) protein within circulating tumor cells (CTCs) identified in patient blood samples. Used in the clinic, the test result serves as a validated biomarker of futility for patients with progressing metastatic castration-resistant prostate cancer (mCRPC) who are treated with androgen receptor targeted therapies (AATT) in whom nuclear-localized AR-V7 CTCs are identified and have received level 2A evidence in the 2019 National Cancer Center Network (NCCN) guidelines (v1.0).

Methods: Assay development was completed on the Epic Sciences rare cell detection platform using control cell lines of known AR-V7 status and clinical testing of mCRPC patient samples obtained at the decision point in management.

Results And Conclusions: Using these samples, all assay parameters, scoring criteria, and clinical cutoffs for positivity were prospectively selected and locked. After assay lock, blinded clinical validation testing was initiated on multiple, independent, clinical cohorts as reported by Scher et al (JAMA Oncol. 2016;2:1441-1449; JAMA Oncol. 2018;4:1179-1186) and Armstrong et al (J Clin Oncol. 2019;37:1120-1129).

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