Two research teams recently reported results from studies involving the long-term evaluation of non-invasive DNA fragments in blood. Evaluating these DNA fragments is called liquid biopsy, and this type of biopsy could vastly improve outcomes through early detection and low false positive rates for a wide variety of cancers. One result is Chinese and the other American.
US & Canada
GRAIL is using deep sequencing of circulating cell-free nucleic acids (cfNAs) to develop assays to detect cancer early in blood. GRAIL recently published data validating its liquid biopsy as a screen for fifty of the most common cancers. The test uses machine learning to detect a cancer’s tissue of origin (TOO) for patients who test positive. Based on data from more than 1,300 patients in its validation cohort, GRAIL’s liquid biopsy proved up a false positive rate of 0.7%, making it potentially eligible for population-scale use. Its sensitivity, or false negative rate, was 56.1% – meaning: A negative result does not rule cancer out but a positive result likely rules cancer in. For patients with positive tests, the TOO was correct 93% of the time, even in Stage 1. In terms of the early detection of pancreatic cancer, a dangerous form of cancer especially after it has metastasized, results suggests a whole new method of defeating this cancer.
According to Ark Invest, GRAIL could have a positive predictive value of 51% in a large, asymptomatic population, roughly 13X better than the current USPSTF screens for breast, colorectal, and cervical cancers.
The study, a prospective, multicenter, case-control, observational effort, has enrolled approximately 15,000 participants across 142 sites in the U.S. and Canada, and includes both people who had cancer at the time of enrollment (newly diagnosed, and not yet received treatment) and people who did not have a known cancer diagnosis. Planned (longitudinal) follow-up for all participants is at least five years to collect clinical outcome data.
China
Started in 2007, the Taizhou Longitudinal Study (TZL) reported results using PanSeer, a noninvasive blood test based on circulating tumor DNA methylation. 123,115 healthy subjects aged 25 to 90 years provided blood samples for long-term storage from 2007 to 2014; these individuals were then indefinitely monitored for cancer occurrence through linkages with local cancer registries and health insurance databases. By the end of 2017, a total of 575 initially healthy subjects (who presented as asymptomatic) were diagnosed with one of five common cancer types (stomach, esophagus, colorectum, lung or liver) within 4 years of initial blood draw. These five cancer types were chosen because they had high incidence rates in the Taizhou cohort and in combination account for the highest mortality in China.
By retrospectively interrogating the initially collected blood samples, scientists were able to assess if cancer could be identified prior to conventional diagnostic methods. Panseer also provided assays for plasma samples from an additional 223 cancer patients, plus 200 primary tumor and normal tissues. PanSeer detects five common types of cancer in 88% (95% CI: 80–93%) of post-diagnosis patients with a specificity of 96% (95% CI: 93–98%). They also demonstrate that PanSeer detects cancer in 95% (95% CI: 89–98%) of asymptomatic individuals who were later diagnosed, though future longitudinal studies are required to confirm this result. These results demonstrate that cancer can be non-invasively detected up to four years before current standard of care.
The study was conducted with researchers at University of California San Diego School of Medicine and Moores Cancer Center and with colleagues at Sun Yet-sun University Cancer Center and other collaborating institutions. Kun Zhang, a bioengineer at the UC San Diego, is a co-author of the study.
China’s Biotech Industry
Foreign direct investment (FDI) is a major contributor to the development of China’s biotech industry, and venture capital (VC) is emerging as another source of growth. Investing in China through FDI enhances transfer of intellectual property rights and integration into global supply chains. Of the 236 foreign mergers and acquisitions (M&A) in the Chinese pharmaceutical and biotechnology industries occurring since 2000, 84% took place between 2003 and 2011; 78% of greenfield investment occurred after 2008. Inbound VC saw modest activity starting in 2007, averaging 5.6 funding rounds and $140 million per year until a sharp increase to over 15 rounds and $590 million per year from 2015-2017, according to the U.S.-China Economic and Security Review Commission.
