Author Interviews, Biomarkers, Cancer Research / 28.06.2020

MedicalResearch.com Interview with: Dr. Kathryn Lang VP, Outcomes and Evidence Guardant Health  MedicalResearch.com: What is the background for this study? Response: Despite a wide variety of screening methods available and increasing public awareness of the value of early detection, colorectal cancer (CRC) remains a leading cause of cancer-related deaths.  However nearly 1 in 3 adults in the United States  is not compliant with screening recommendations, with most citing that current screening methods are time consuming, unpleasant (stool-based testing), and in the case of colonoscopy, invasive. A blood-based CRC screening test could improve compliance rates by providing physicians with an opportunistic, in-office screening modality. However, demonstrating the clinical utility of blood-based cell-free circulating tumor DNA (ctDNA) fractions  for the detection of cancer in asymptomatic individuals has thus far been challenged by the failure to achieve clinically meaningful sensitivity and specificity thresholds due to significantly lower tumor cell-free free DNA  fractions and the increasing relevance of biological confounders. The multi-modal approach of Guardant Health’s LUNAR-2 assay (genomics, methylation and fragmentomics) coupled with advanced bioinformatic analysis and a focused approach of honing in on the unique signals of CRC  has been shown in previously reported cohorts to perform with sensitivity and specificity which satisfies the needs of clinicians in screening for CRC. (more…)
AACR, Author Interviews, Biomarkers, Cancer Research, Colon Cancer / 26.06.2020

MedicalResearch.com Interview with: Guardant HealthVan Morris, M.D. Department of Gastrointestinal Medical Oncology Division of Cancer Medicine MD Anderson Center MedicalResearch.com: What is the background for this study? Response: Stage II colon cancer is diagnosed in approximately 25% of all colon cancer cases.  Oncologists do not have a reliable biomarker to identify patients who do or do benefit from adjuvant chemotherapy for this population of patients.  Circulating tumor DNA is shed by tumor cells as they die and harbors somatic mutations which distinguish its DNA from that of normal cells. Recently, circulating tumor DNA has shown great promise in distinguishing patients with colon cancer (as well as other solid tumors) that do or do not recur after surgery.  Here, patients who have detectable circulating tumor DNA - a surrogate for the presence of microscopic, minimal residual disease – inevitably recur, whereas the likelihood of recurrence is much lower for patients who do not have detectable ctDNA. (more…)
Author Interviews, Cancer Research, Genetic Research / 04.05.2020

MedicalResearch.com Interview with: Rebecca Nagy Vice President Medical Affairs Guardant Health  MedicalResearch.com: What is the background for this study? Response: Hormone receptor positive (HR+) breast cancer comprises roughly 75% of all cancers of the  breast. While many of these cancers can be cured through multi-modality therapy, there remain many deaths due to metastatic spread to distant organs. These metastatic cancers are marked by their resilience in the face of potent targeted therapies and chemotherapies, with many tumors displaying an initial drug response followed by resistance. Recently, genomic sequencing has identified recurrent, oncogenic alterations in HR+ metastatic breast cancer (MBC) with mutations in the catalytic alpha subunit of PI3K (PI3Kα, PIK3CA gene), in over 40% of cases. This has raised hopes for more durable disease control through precise inhibition of this driver oncogene. The SOLAR-1 Phase III study of alpelisib combined with fulvestrant in PIK3CA-mutated HR+ MBC showed a markedly improved PFS over fulvestrant monotherapy but pervasive resistance nonetheless. To characterize the basis for such resistance to combination hormone plus PIK3CA targeted therapy, we conducted a detailed, longitudinal analysis of tumor and plasma circulating cell-freetumor DNA (ctDNA) among patients with HR+ MBC who participated in a phase I/II dose escalation study of alpelisib in combination with letrozole or exemestane.  (more…)