Grail has taken a few more steps forward in its quest to develop a diagnostic test capable not only of spotting cancer in its earliest stages, but also identifying its location within the body using markers taken from the bloodstream.
This past summer, the company presented early study data in Chicago during the annual meeting of the American Society of Clinical Oncology (ASCO) that demonstrated its liquid biopsy exam could detect 12 different cancers before they’ve had a chance to grow and metastasize to different parts of the body.
Now—across the Atlantic in Barcelona at the European Society for Medical Oncology’s 2019 congress—the test has shown new data on its ability to screen for more than 20 types and subtypes of the disease and determine their tissues of origin.
Researchers at the Dana-Farber Cancer Institute, Cleveland Clinic, Mayo Clinic and others delivered an analysis of data collected from participants in Grail’s longitudinal Circulating Cell-free Genome Atlas Study and its STRIVE study.
The next-generation sequencing test searches for DNA strands that are shed from dying cancer cells and found circulating in the bloodstream. It then hunts for tiny chemical tags, affixed to the DNA through methylation, that turn the expression of individual genes on or off. Abnormal methylation patterns can betray the presence of cancer, according to the former Fierce 15 winner.
"Our previous work indicated that methylation-based assays outperform traditional DNA-sequencing approaches to detecting multiple forms of cancer in blood samples," lead author Geoffrey Oxnard, a medical oncologist at Dana-Farber, said in a statement. "The results of the new study demonstrate that such assays are a feasible way of screening people for cancer."
Researchers applied the test to over 3,580 blood samples taken from participants with and without prior cancer diagnoses and found it was able to deliver 99.4% specificity, or a false-positive rate of 0.6%.
The patient samples included those with hormone receptor-negative breast, colorectal, esophageal, gallbladder, gastric, head and neck, lung, lymphoid leukemia, multiple myeloma, ovarian and pancreatic cancers.
Among a pre-specified set of cancers with particularly high mortality rates—such as hepatobiliary cancer, lymphoma and those above—the test’s sensitivity reached 76%, and varies by how far the cancer has developed. Grail’s test was able to correctly spot 32% of the earliest cases in stage 1; 76% in stage 2; 85% in stage 3; and 93% in stage 4, or advanced metastatic disease.
Those numbers are mostly in line with the data presented at ASCO in late May, spanning a dozen cancers. Across all the cancer types included in the ESMO study, the overall sensitivity rate was 55%. Additionally, 97% of samples returned a result for a tissue of origin, with the test identifying the location correctly in 89% of cases.
“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,” former Grail CEO Jennifer Cook said after the release of the ASCO data, adding that the company plans to advance its test toward commercialization. In June, former Juno Therapeutics helmsman Hans Bishop was named CEO as Grail begins to prep for market.
The company also said it plans to present additional data from its test at ASCO's Breakthrough global summit, held next month in Bangkok, Thailand.