Study validates next-generation sequencing approach compared to the current standard method of PCR fragment analysis on more than 2,000 cases
Relationship between immunotherapy associated biomarkers, MSI, TMB and PD-L1, explored across an unprecedented 11,348 cases
Highly relevant due to recent FDA approval of pembrolizumab to treat MSI-H regardless of tumor origin
IRVING, Texas, Feb. 14, 2018 – Caris Life Sciences®, a leading innovator in molecular science focused on fulfilling the promise of precision medicine, today announced an article published in the peer-reviewed journal Cancer Medicine validating the use of the Company’s next-generation sequencing platform to detect microsatellite instability (MSI), and comparing the relationship of MSI with tumor mutational burden (TMB) and programmed death ligand 1
(PD-L1). The study, entitled “Microsatellite instability status determined by next-generation sequencing and compared with PD-L1 and tumor mutational burden in 11,348 patients,” demonstrated that MSI by NGS is highly concordant with the traditional standard method of PCR fragment analysis (PCR-FA) and is a more efficient and cost-effective approach to identifying patient candidates for immunotherapy.
“The recent approval of pembrolizumab for high MSI (MSI-H) and mismatch repair-deficient tumors, regardless of the tissue of origin, creates the need for an efficient and cost-effective approach that is necessary to identify these patients, for example the use of molecular profiling,” said W. Michael Korn, M.D., Chief Medical Officer of Caris Life Sciences. “Traditionally MSI testing requires both normal and tumor tissue, however the Caris NGS assay only requires tumor tissue, thus reducing the burden on patients and increases the percent of time a viable result can be returned. In addition to MSI status, the Caris NGS approach provides information about Tumor Mutational Burden and alterations in hundreds of clinically relevant genes.”
The study evaluated 2,189 cases that spanned 26 cancer types, of which 1,108 were colorectal cancer (CRC), to compare mismatch repair status of Caris’ NGS platform to the current industry standard of PCR-FA. When compared to PCR-FA, MSI-NGS in CRC had sensitivity of 100% and specificity of 99.9%, and MSI-NGS across all 26 cancers had sensitivity of 95.8% and specificity of 99.4%. The NGS assay identified MSI-H cases in 23 different tumor types. These results led the authors to conclude that the assay allows for the detection of MSI-H across a broad range of cancer types. Unlike PCR-FA, MSI-NGS does not require normal tissue to compare to tumor tissue, making it applicable for patients with minimal biopsied normal tissue.
Determination of MSI status is crucial for directing the use of immune checkpoint inhibitor therapies, and the authors also compared the relationship of MSI to other known biomarkers for these drugs. To do this, the investigators studied the relationship of MSI-H to both TMB and PD-L1 expression across 11,348 cases. MSI-H was identified in 3.0% of cases, TMB in 7.7% of cases and PD-LI expression in 25.4% of cases. Thirty percent of MSI-H cases were TMB-low and only 26% of MSI-H cases were PD-L1 positive. The overlap between TMB, MSI and PD-L1 differed among cancer types. Only 0.6% of the cases were positive for all three markers.
“Since we have performed PCR-FA MSI testing on thousands of patients, we had a unique dataset with which to calibrate our MSI-NGS assay,” said David Spetzler, M.S., Ph.D., M.B.A., President and Chief Scientific Officer of Caris Life Sciences. “Our MSI-NGS assay is calibrated across more than 2,000 PCR-FA cases and the MSI data published here, across more than 11,000 samples, shows the magnitude of clinical impact this test can have for patient care. At Caris, we strongly believe that specific mutations and molecular signatures are major drivers that should be used to determine therapeutic strategies rather than just the tissue of origin for tumors. This makes broad-based, multi-platform profiling increasingly important for every cancer patient.”
About Caris Life Sciences®
Caris Life Sciences® is a leading innovator in molecular science focused on fulfilling the promise of precision medicine through quality and innovation, and the world’s leading immunotherapy diagnostic expert. Caris Molecular Intelligence®, the company’s Comprehensive Genomic Profiling Plus (CGP+) molecular testing service, assesses DNA, RNA and proteins, including microsatellite instability (MSI), tumor mutational burden (TMB) and PD-L1, to reveal a molecular blueprint to guide more precise and personalized treatment decisions. The ADAPT Biotargeting System™, the company’s revolutionary and unbiased profiling platform, is currently being utilized for drug target identification, therapeutic discovery and development, fixed tissue-based companion diagnostics, blood-based cancer screening and biomarker identification. Headquartered in Irving, Texas, Caris Life Sciences offers services throughout the U.S., Europe, Asia and other international markets. To learn more, please visit www.CarisLifeSciences.com.