Liquid biopsy pioneer GRAIL is a step closer to developing a single blood test to find cancer early. The company’s candidate blood test detected a strong signal for 12 cancer types at stages I-III, according to results which will be presented today at the American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago. Further, the test performed with a specificity of at least 99 percent (or a false positive rate of one percent or less). The test also predicted each cancer’s site of origin with high accuracy. These are early data from GRAIL’s Circulating Cell-free Genome Atlas (CCGA) study, which comprises samples from about 15,000 patients.
While these data are preliminary, they appear promising.
Detection rates (sensitivity) at early stages for the 12 cancers ranged from 59 percent to 86 percent. A combined analysis showed detection levels of 34 percent, 77 percent, and 84 percent respectively, for stages I, II, and II. In 90 percent of all cases the test also correctly identified the tissue of origin. The cancer types included anorectal, colorectal, esophageal, gastric, head and neck, hormone receptor negative breast, liver, lung, ovarian, and pancreatic cancers, as well as multiple myeloma and lymphoid neoplasms. This group of cancers accounts for approximately 63 percent of all cancer deaths in the United States.
“These exciting results suggest we can achieve what we believe are the requirements for a cancer screening blood test, including detection of multiple deadly cancer types at early stages in a single test, high accuracy in determining where the cancer originated, and a very low false positive rate,” said Jennifer Cook, Grail’s CEO. “Our improved methylation-based technology has the potential to address gaps that exist with today’s screening options, which are limited to a few cancer types and only screen for one cancer type at a time.” GRAIL’s sequencing database of cancer and non-cancer methylations signatures is believed to be the largest of its kind and covers approximately 30 million methylation sites across the genome.
With $1.6 billion in venture capital, GRAIL is a favorite to launch the first risk-determining liquid biopsy test. The company is privately owned and backers include Jeff Bezos and Bill Gates. The entire market for liquid biopsies is estimated to reach $2 Billion by 2020. This includes tests for monitoring, prognosis, theranostics, and screening.
The CCGA is a key to GRAIL’s future. It is a prospective, multi-center, observational study that has enrolled approximately 15,000 participants, both with and without cancer, from clinical networks in the United States and Canada. Clinical information, demographics, and medical data relevant to cancer status are collected from all participants and their medical record at baseline (time of biospecimen collection), and then from their medical record at intermittent future time points, at least annually for up to 5 years.
Additional early CCGA results being presented at ASCO this year showed that for more than 20 cancer types, detection was 55 percent across all stages. Tissue of origin results across these 20 cancer types was again accurate in 90 percent of cases. This sub-study looked data from approximately 2,300 participants.
“These very promising data indicate that a highly specific blood test for early cancer detection is approaching reality,” said Dr. Minetta Liu, research chair and professor in the Department of Oncology at Mayo Clinic, and an investigator on the CCGA study. “The exceptional accuracy in determining the tissue of origin across all stages for those malignancies with significant cancer-specific mortality suggests that, if a cancer is detected, the test will inform where the tumor originated in the majority of cases. This factor is critical to streamline the clinical workup.”