Biocept and Clarient have entered a collaboration to commercialize a blood test for circulating tumor cells (CTCs) in breast cancer patients, which includes the determination of Her2 status. Clarient and Biocept will market and sell the latter’s OncoCEE-BR™ CTC test to community hospitals, pathologists, and medical oncologists.
Biocept has demonstrated detection of Her2-amplified CTCs in patients with Her2 negative primary tumors. This suggests that the pathologist may have examined a part of the tumor that was not Her2 amplified and that treatment with Her2-targeted agents may be justified.
Biocept will perform the test in its laboratories, and results will be interpreted by Clarient's pathology group, Clarient Pathology Services. The test includes CTC enumeration and Her2 status of the detected CTCs by FISH. Biocept intends to add ER/PR status determination to the test and potentially other biomarkers in the future.
It is reportedly the first commercially available CTC test to include analysis of a specific treatment-associated biomarker. It also is unique in that it combines enumeration and cytogenetic characterization.
The OncoCEE-BR test is expected to have application in several clinical settings, including: at the time of recurrence and especially in cases where a biopsy may be difficult to obtain to determine if the patient's Her2 status has changed from the original diagnosis or surgery; confirmation of Her2 status at the time of original diagnosis or surgery, where tumor tissue analysis was negative for Her2 amplification.
Biocept’s pipeline of CTC tests is based on its CEE™ (cell enrichment and extraction) platform. The tests will be provided as a service to physicians and patients as well as pharmaceutical and biotechnology companies through Biocept's CLIA-certified, CAP-accredited laboratory. The CEE platform comprises microfluidic capture channels and associated instrumentation, an antibody capture cocktail, and CEE-Enhanced™ staining technology, with biomarker assays being performed on CTCs captured in the channels.
The OncoCEE platform has demonstrated that it can consistently and accurately capture extremely rare cells from blood, like CTCs, which may be present in only 1 of every 50–100 billion blood cells, according to Biocept. Other methods to capture, detect, and enumerate CTCs rely only on the expression of the epithelial cell adhesion (EpCAM) molecule and cytokeratins and do not include molecular biomarker analysis. This approach may exclude CTCs that have undergone intrinsic modifications of their phenotype, such as the epithelial-to-mesenchymal transition (EMT).
EMT may represent a possible explanation for many patients who, despite an aggressive disease, are found negative for the presence of CTCs. OncoCEE captures epithelial CTCs and mesenchymal-like CTCs. Additionally, it enables evaluation of diagnostic biomarkers by techniques like immunocytochemistry, FISH, and mutation analysis.
"We believe the combination of the technical advantages of the OncoCEE-BR™ test, and Clarient's highly regarded marketing and pathology capabilities, will enable the rapid education of the physician community about the benefits of CTC analysis for patients with breast cancer," says David Hale, executive chairman of Biocept.
"We think a blood-based, CTC-directed Her2 test that can be performed when a treatment decision arises has high potential and expect that it will be used to support other laboratory and clinical information to provide physicians with the most current information on a tumor to help select the most appropriate course of therapy."