
Third Rock unveils liquid biopsy biotech, leading $110M bet it can Thrive in early cancer detection
Cancer is the second leading cause of death globally — the earlier it is detected, the better shot patients have of bouncing back. Researchers have long pursued a minimally-invasive, effective test to expose early markers of the often deadly disease, and weeks ago Grail blueprinted its strategy for its blood test for early cancer detection. On Thursday, Third Rock Ventures unveiled its shot at that lofty goal, with the launch of a liquid biopsy company that has raised a meaty $110 million in its first round.
The company, aptly named Thrive Earlier Detection, is betting on CancerSEEK — its blood test-in-development designed to sniff out eight common cancer types by interrogating genomic mutations in circulating tumor DNA (ctDNA) as well as protein markers in plasma that have been implicated in cancer.
“It’s great to be part of an area, where (…) we could do for cancer what 50 years ago we did for heart disease, when we started screening for high blood pressure for example,” said Steven Kafka, Thrive CEO and partner at Third Rock Ventures, in an interview with Endpoints News ahead of the announcement.
CancerSEEK is engineered to not only be powered to identify the presence of relatively early cancer, but uses machine learning to localize the organ of origin of the cancer — eventually, the hope is the test will be used as part of the arsenal of routine medical screening tools, to complement existing disease-specific screening methods such as mammography and colonoscopy.
In a retrospective study, encompassing 1,005 patients with non-metastatic, clinically detected cancers of the ovary, liver, stomach, pancreas, esophagus, colorectum, lung, or breast published in the journal Science last year, CancerSEEK tests were positive in a median of 70% of the eight cancer types.
Data showed the sensitivity of the test ranged from 69% to 98% for the detection of five cancer types — ovary, liver, stomach, pancreas, and esophagus — for which there are no screening tests available for average-risk individuals. Meanwhile, the ability of the test to hone in on the organ of cancer origin was > 99% — although 7 out of 812 healthy controls scored positive. In addition, CancerSEEK localized the cancer to a small number of anatomic sites in a median of 83% of the patients.
After data from the CancerSEEK study was published, Science writer Derek Lowe suggested there was room for improvement, but it constituted a good start. “The bigger problem is if you’re going to use this test for early detection: when the team looked at the detection rates adjusted for the stage of the diagnosed tumors, CancerSEEK turned out to only catch 43% of the Stage I cases overall,” he wrote in a post.
Image: Bert Vogelstein THRIVE
CancerSEEK has been granted the FDA’s breakthrough device status, as has Grail’s multi-cancer detection blood test, which relies on DNA sequencing to assess methylation, an epigenetic change across the genome to expose cancer signals.

Grail, which was spun out of DNA sequencing company Illumina $ILMN in 2016, has raised $1.6 billion in funding to fuel the development of its test, which is now being evaluated in three large-scale studies that will altogether enroll 165,000 individuals.

Thrive — which was founded by three cancer researchers Bert Vogelstein, Kenneth Kinzler and Nickolas Papadopoulos at Johns Hopkins University — is also evaluating CancerSEEK in a large prospective study. The trial, called DETECT, has enrolled 10,000 healthy women aged between 65 and 75 without prior cancer history.
Data from DETECT should be available sometime next year, Kafka said.
“We have a goal of it (CancerSEEK) being in the hundreds of dollars, commercially, not thousands of dollars… single disease tests like (Exact Science’s) Cologuard are list priced at $600 or $700, a mammography costs $100 to $200 and if you think of those as the guard rail — we have a multi cancer test that already we believe is performing within that level of cost.” he added.
Third Rock Ventures led the $110 million Series A financing, with participation from Section32, Casdin Capital, Biomatics Capital, BlueCross BlueShield Venture Partners, The Invus Group, Exact Sciences $EXAS, Cowin Venture, Camden Partners, Gamma 3 LLC and others.
Other companies such as Guardant Health and Biocept are also working on their own liquid biopsy tests. Each company is looking to champion consistency and accuracy — false positives induce unnecessary anxiety, and are costly. Another concern is of course, privacy.
Image: Steven Kafka THRIVE