California-based biotechnology company Biocept, Inc. (Nasdaq: BIOC), which has developed an assay-based technology designed to identify cancer-associated genetic mutations from liquid biopsy tests, has announced the publication of clinical data demonstrating high sensitivity and specificity of their assay as compared to that of traditional tissue biopsies.
Biocept’s liquid biopsy-based assay is intended to provide physicians with a method for detecting cancer metastases to the brain or central nervous system using cerebrospinal fluid samples drawn from their patients. The assay is already clinically available for breast or lung cancer patients with suspected brain metastases. “Up to 30% and 36% of patients diagnosed with breast and lung cancer, respectively, will develop brain metastases,” stated a press release.
Senior Vice President and Senior Medical Director Veena Singh, MD, stated, “Results from this study showed a very high concordance rate between our liquid biopsy testing and tissue biopsy, providing further clinical validation of our Target Selector™ technology. Our clinical testing demonstrates best-in-class detection of alterations down to a single mutant copy, not only in an analytical setting but in a clinical setting as well. Further the ability to inform clinical decision making in a significantly more cost-effective manner potentially affords the healthcare system a highly sensitive and cost-effective option.”
The study, published in the Journal of Clinical Pathology, compared the efficacy of the liquid biopsy technology versus that of traditional tissue biopsies for detecting three genes commonly mutated in various types of cancer: the gene encoding the epidermal growth factor receptor (EGFR), which is frequently altered in lung cancer patients, particularly those with non-small cell lung cancer; the gene encoding B-Raf, whose mutations have been associated with many types of cancer from melanoma to colorectal and lung cancer; and the KRAS gene, whose mutations can lead to lung, pancreatic, colorectal, and other cancers.
According to Biocept,”The study examined 127 clinical assays for mutations commonly associated with cancer found in the EGFR, BRAF and KRAS genes. Each Target Selector™ assay in the study demonstrated extremely high accuracy, sensitivity and specificity when compared to results obtained from tissue samples, showing a 93%-96% concordance to blinded tissue samples across all assays.”
President and Chief Executive Officer of Biocept Michael Nall stated, “The continued validation of our technology demonstrates its ability to non-invasively identify biomarkers specific to cancer, and to aid physicians in selecting optimal therapeutic treatments for their patients. We are pleased to report that our biomarker testing has been performed in more than 25,000 patients to date, and results from this study further illustrate the enhanced performance of our Target Selector™ technology.”
Biocept’s liquid biopsy-based approach involves the amplification and sequencing of cancer-associated DNA isolated from the cerebrospinal fluid or peripheral blood of cancer patients and is intended to overcome common limitations of traditional tissue-based biopsies including procedural risks and difficulty, potentially biased sampling, and challenges associated with capturing multiple biopsies to track cancer progression.
The authors of the publication concluded that Biocept’s liquid biopsy technology offers a “highly effective” and non-invasive method of characterizing cancer patients’ “molecular signatures.”
Liquid biopsies are useful for detecting circulating tumor cells (CTC), which are derived from the original tumor site and circulate throughout the body in the bloodstream, and for the detection of circulating tumor DNA (ctDNA), which can be released by the original tumor or by CTCs. Since the mutations in ctDNA reflect those of the original tumor, ctDNA can be used as a diagnostic and prognostic marker and enable physicians to track the disease progression and the effectiveness of cancer treatments.
According to the American Cancer Society, an increase in ctDNA levels can be observed months before the “visible” recurrence of cancer, providing physicians with the opportunity to respond more quickly. In addition to cancer, liquid biopsies can be used to support the diagnosis of a heart attack through sampling circulating endothelial cells and for diagnosing unborn children via samples collected from the amniotic fluid or from the blood of the pregnant mother.
In January 2020, Biocept announced the availability of its liquid biopsy assays in the clinic for lung and breast cancer patients with possible brain or central nervous system metastases. Cerebrospinal fluid collected by lumbar puncture could, with the discretion of the treating physician, be evaluated using the technology for the presence of cancer-associated DNA.
Santosh Kesari, MD, PhD, Chair and Professor, Department of Translational Neurosciences and Neurotherapeutics, Director of Neuro-oncology at the Pacific Neuroscience Institute and John Wayne Cancer Institute, stated, “Testing the CSF for cancer biomarkers in patients suspected to have brain metastases can be important, as the rapid confirmation and characterization of CNS involvement enables appropriate treatment selection in a timely manner. Liquid biopsy tests offer the ability to analyze an additional specimen type, beyond blood, to help physicians identify biomarkers and hence inform clinical decision making.”
Biocept President and CEO Michael Nall stated, “We are very pleased to make our Target Selector™ platform available for testing CSF, as a more rapid identification of molecular alterations in brain metastases can aid physicians in choosing the best treatment options for their patients with breast or lung cancer. Among the significant capabilities of our technology is its versatility, which enables applications in a variety of clinical situations and for use with multiple types of biofluids.”
Arnold L, Alexiadis V, Watanaskul T, et al. (2020) Clinical validation of qPCR Target Selector™ assays using highly specific switch-blockers for rare mutation detection. The Journal of Clinical Pathology. DOI: http://dx.doi.org/10.1136/jclinpath-2019-206381