Guardant Health is one of the biggest names in liquid biopsy and after Monday its presence in the space can only increase. The Redwood City, CA-based company revealed results of a study conducted by it along with researchers from The University of Texas MD Anderson Cancer Center, the Samsung Medical Center, and other institutions.
Results show the Guardant360 assay can accurately detect microsatellite instability status (MSI) as accurately as tissue biopsy. The company said this is the largest comparison of MSI testing to traditional tissue methods across multiple solid tumor types. Findings were reported in Clinical Cancer Research.
For advanced cancer patients, MSI is a good predictor of response to immunotherapy with PD-1 and PD-L1 inhibitors in multiple tumor types. It has been reported to occur in about 1% of cases, and any patient with advanced cancer who is found to be MSI-High is eligible for treatment with immunotherapy. MSI-High occurs most frequently in colorectal, endometrial, and gastroesophageal cancers.
To validate Guardant360’s MSI detection, researchers compared the results of 1,145 Guardant360 samples to MSI status determined using standard-of-care tissue testing results taken from medical records. The results from Guardant360 were the same as the standard-of-care tissue test in 98.4% of cases.
Additionally, it is the first report of immune checkpoint inhibitor therapy outcomes in plasma MSI-High patients. In a cohort of 16 MSI-High gastric cancer patients treated with immune checkpoint inhibitors, the objective response rate was 63% and the disease control rate was 81%, consistent with responses for patients identified by tissue testing.
“These results show that a carefully designed panel, combined with efficient DNA-capture biochemistry and sophisticated bioinformatics tools, allow for accurate, sensitive MSI detection,” Scott Kopetz, MD, PhD, Associate Professor of Gastrointestinal Medical Oncology at The University of Texas and co-author on the study, said in a release.
The results could be a significant boon for Guardant as the liquid biopsy market continues to ramp up. In June, Thrive Earlier Detection Group, a new player in the space made its presence known by announcing it raised $110 million series A round.
The results also come on the heels of Guardant’s liquid biopsy rival Grail revealing results at the ASCO 2019 meeting from the Circulating Cell-free Genome Atlas study. Results show the Menlo Park, CA-based company’s solution detected a strong signal for 12 deadly cancer types at early stages with a very high specificity of at least 99%.
Before announcing the CCGA data, Grail was granted Break Through Device Designation by FDA for the next-generation sequencing (NGS) blood test for the early detection of multiple cancer types in individuals 50 or older.