Silicon Valley startup Grail sees hope for blood test

The quest for a simple blood test to catch cancer early has attracted heavy hitters from Bill Gates to Merck & Co. Now there’s a glimpse of evidence that it can work, at least for one type of malignancy.

A study led by Hong Kongbased researchers and published this week in the New England Journal of Medicine used DNA fragments in the blood to detect a kind of head and neck cancer called nasopharyngeal carcinoma. The procedure, known as a “liquid biopsy,” caught the cancer earlier and more accurately than existing methods — and ultimately boosted patients’ chances of survival.

The results could help the commercial prospects for Grail Inc., a closely held Silicon Valley startup that has raised more than $1.1 billion since its 2016 founding from investors including billionaires Gates and Jeff Bezos, as well as Merck and China’s Tencent Holdings. Dennis Lo, one of the study’s main authors and a professor in Hong Kong, is also the co-founder of a biotech company called Cirina, which agreed to merge with Grail in May.

The rise of technologies like genetic sequencing have spurred hopes that new, non-invasive tests could revolutionize cancer care. Detecting the disease early can make treatment dramatically more effective, and investors have been eager to fund ventures focused on such preventative health care.

“It’s our aspiration to create a commercial test” for nasopharyngeal carcinoma, said Grail’s president, Ken Drazan. If successful, the test, to be marketed in Southeast Asia, would be Grail’s first product.

Dozens of companies have worked to develop or sell some form of liquid biopsy test, according to a 2015 report from Piper Jaffray. But most have been focused on tests for patients who have already been diagnosed.

The dream of a non-invasive cancer-detecting test is based on findings that tumors are constantly shedding fragments of DNA into the bloodstream. While blood tests are already marketed to track a tumor’s mutation after it’s been diagnosed, detecting early-stage cancer is trickier, partly because the cancerous DNA is shed in much smaller amounts.

Nasopharyngeal carcinoma provided a proof-of-concept experiment for the team of researchers, which included Allen Chan, Rossa Chiu and Lo from the Li Ka Shing Institute of Health Sciences of the Chinese University of Hong Kong. All three are co-founders of Cirina.

The cancer, which is prevalent in southern China and Southeast Asia, arises from a confluence of factors: besides genetic mutations, it’s also associated with consumption of salted fish and smoking, as well as infection with the Epstein-Barr virus, which is a member of the herpes virus family.

In the study, 70 percent of the diagnoses found the cancer in early stages, Lo said, adding that nasopharyngeal carcinoma typically goes undetected.