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RareCyte announces first commercially available ARv7/Synaptophysin CTC assay for blood-based characterization of treatment resistant prostate cancer

Seattle, WA, August 26, 2020 – RareCyte® announces a new dual biomarker liquid biopsy assay for androgen receptor splice variant 7 (ARv7) and the neuroendocrine marker, synaptophysin (SYP), enabling customers to evaluate both ARv7 and SYP expression on circulating tumor cells (CTCs) with industry leading accuracy and precision in patients with prostate cancer. The ARv7/Synaptophysin Panel Kit was validated based on rigorous requirements set to clinical standards and enables blood-based investigation of two prominent mechanisms by which tumors become resistant to second-line endocrine therapies.

“Resistance to second-line anti-androgen therapies has emerged as an important clinical challenge” explained Eric Kaldjian, MD, Chief Medical Officer of RareCyte. “New therapies are in development to target the resistance mechanisms. Identification of ARv7 and synaptophysin on CTCs via a non-invasive blood sample will allow investigational monitoring for tumor transformation, as well as confirmation of clinically suspected resistance in multi-center clinical trials.”

The assay comprises processing blood to slides with the AccuCyte® Sample Preparation System followed by staining with the RarePlex® 0919-LB ARv7/Synaptophysin CTC Panel Kit and imaging on a CyteFinder® Instrument. Machine learning enabled analysis and scoring maximizes reviewer concordance. In addition, the RareCyte platform enables cell-free DNA analysis on the same sample, providing a comprehensive liquid biopsy assessment of tumor status.

“In prostate cancer, ARv7 has been associated with resistance to certain therapies, and SYP is a commonly used histologic marker for the neuroendocrine phenotype” said Amir Goldkorn, MD, an oncologist at University of Southern California (USC) Norris Cancer Center and associate professor of medicine at Keck School of Medicine of USC. Goldkorn and his collaborators at USC Norris Cancer Center collaborated with RareCyte to validate the assay. “Using the ARv7/SYP assay, it will be exciting to test whether CTCs bearing these markers are associated with unique biological phenotypes or clinical outcomes in men with prostate cancer.”

The ARv7/Synaptophysin CTC Panel Kit is now available for purchase; more information on the kit and the RareCyte platform is available at

About RareCyte, Inc.

RareCyte offers Precision Biology solutions focused on multiplexed analysis of cells and tissue with applications in life science research and clinical diagnostics. The company has deep experience in developing advanced precision systems and consumables used in cutting-edge labs worldwide. Our customers perform innovative research, bring new therapeutic and diagnostic assays to market, and perform a wide range of single cell applications in oncology and disease research.

For Research Use Only. Not for use in diagnostic procedures.

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