Integration of CTC (Circulating Tumor Cell) enumeration* to decide between endocrine therapy and chemotherapy may lead to improved clinical outcomes and quality of life for patients with oestrogen receptor (ER) positive)/human epidermal growth factor receptor (HER) 2 negative metastatic breast cancer (MBC).

BOLOGNA, Italy and HUNTINGDON VALLEY, Pa., Dec. 22, 2022 /PRNewswire/ -- Menarini Silicon Biosystems, a pioneer of liquid biopsy and single cell technologies, announced the promising long-term results of the STIC trial, on OS (overall survival) in patients with ER+/HER2- MBC. This robust (n=755), randomized, multicenter phase III study aimed to compare the efficacy of a clinician- vs CTC-driven treatment choice. After meeting its primary endpoint on PFS (progression free survival) in 2018[1], follow-up data presented orally by Professor Francois-Clément Bidard at the 2022 San Antonio Breast Cancer Symposium (SABCS) on December 8th, demonstrates that a single assessment of CELLSEARCH CTC count before the start of treatment, may lead to increased OS in a metastatic setting2.

According to FC Bidard, MD, PhD, Professor of Medical Oncology & Coordinator of Breast Cancer research at the Institut Curie hospitals, "we were particularly impressed by the subgroup of patients with a low clinical risk profile and CTC count ≥ 5, for whom physicians, in line with guidelines, selected endocrine therapy (ET). When treated with chemotherapy (ChT) instead, these patients had a superior median OS of 16 months". The trial further showed that, when escalated to ChT, these patients also experienced a 47% reduction in their risk of death. "This is the first ever trial to demonstrate the clinical utility of CTC count in MBC. It paves the way to integrating CTC count into treatment decision algorithms for patients who previously received CDK4/6 inhibitors as first line or adjuvant therapy, and for whom the decision between either a further line of ET or ChT is difficult, heterogeneous and controversial when based only on clinicians' judgment" – he added.

Breast cancer is the most commonly diagnosed malignancy in women worldwide. Among various subtypes, HR+/HER2- is the most prevalent3 and improvement of long-term survival in MBC still remains a challenge.

CELLSEARCH is the first and only clinically validated blood test cleared by the U.S. Food & Drug Administration (FDA) for detecting and counting CTCs in metastatic breast cancer when used in conjunction with other clinical monitoring methods. Because it can capture and enumerate CTCs from just 7.5 ml of peripheral blood, this assay represents a minimally invasive method, compared to more burdensome tumor biopsies, for informing treatment strategies. "We are thrilled by the positive results of our study on the more direct clinical benefit endpoint of OS" said Fabio Piazzalunga, President and CEO of Menarini Silicon Biosystems. "The fact that our CELLSEARCH CTC assay* had such a significant impact on this measure is quite promising. We believe this trial will open new doors to support treatment decisions that optimize patient care for other life-threatening tumor types, considering our desire to be the indisputable leader in non-invasive cell-based applications for easier, faster, and more precise diagnostic and therapeutic approaches."

About CELLSEARCH

CELLSEARCH is the first and only clinically validated blood test cleared by the U.S. Food & Drug Administration (FDA) for detecting and counting CTCs to aid physicians in managing patients with metastatic breast, prostate, and colorectal cancers when used in conjunction with other clinical methods of monitoring. The test is also approved by the China National Medical Products Administration (NMPA) for use in monitoring patients with Metastatic Breast Cancer. The CELLSEARCH System is the most extensively studied CTC technology, with research published in more than 800 peer-reviewed publications.

CELLSEARCH Circulating Tumor Cell Test is not cleared or approved for guiding treatment decisions. For more information on the full intended use and limitations of CELLSEARCH system, please refer to the Instructions for Use at http://documents.cellsearchctc.com/.

CELLSEARCH Circulating Tumor Cell Test is available as a laboratory developed test (LDT) in MSB's CLIA/CAP/ ISO 15189 accredited laboratory in Huntingdon Valley, Pa.

About Menarini Silicon Biosystems (MSB)

MSB offers unique rare cell technologies and solutions that provide clinical researchers with access to unparalleled resolution in the study of cells and their molecular characterization.

Menarini Silicon Biosystems, based in Bologna, Italy, and Huntingdon Valley, Pa., U.S., is a wholly owned subsidiary of the Menarini Group, a multinational pharmaceutical, biotechnology and diagnostics company headquartered in Florence, Italy, with more than 17,000 employees in 140 countries.

* The CELLSEARCH CTC Assay is only cleared by the FDA for detecting and counting CTCs to aid physicians in managing patients with metastatic breast, prostate, and colorectal cancers when used in conjunction with other clinical methods of monitoring. The performance and safety and effectiveness for this new intended use (patient management decision) have not been established, and are not cleared or approved by FDA. 

[1] Bidard FC, et al. Efficacy of Circulating Tumor Cell Count-Driven vs Clinician-Driven First-line Therapy Choice in Hormone Receptor-Positive, ERBB2-Negative Metastatic Breast Cancer: The STIC CTC Randomized Clinical Trial. JAMA Oncol. 2021 Jan 1;7(1):34-41

[2] Bidard FC, et al. Circulating Tumor Cells-driven choice of first line therapy for ER+ HER2- metastatic breast cancer: overall survival analysis of the randomized STIC CTC trial. Oral presentation SABCS 2022, Abstract GS3-09

[3] https://pubmed.ncbi.nlm.nih.gov/34447271/