SOURCE: Integrated Diagnostics

Integrated Diagnostics

March 17, 2015 17:00 ET

Indi® Publishes Technical Paper on Methods to Improve Reproducibility and Robustness of MRM-Mass Spec Proteomic Tests

Paper Details Assay Variability Controls Used in Xpresys® Lung

SEATTLE, WA--(Marketwired - Mar 17, 2015) - Indi (Integrated Diagnostics®) today announced publication of a technical paper in Clinical Proteomics providing details about the assay variability control method used in Xpresys Lung. The new method, called InteQuan, is intended to improve the reproducibility and robustness of Xpresys Lung and other laboratory-developed clinical proteomic assays based on MRM mass spectroscopy (mass spec).

Xpresys Lung is the first MRM mass spec clinical proteomics assay in clinical use. InteQuan involves the use of endogenous protein standards, which are then combined with the standard stable isotope-labeled peptides to control for pre-analytical variation such as differences at sample collection sites -- in addition to analytical variability in the workflow of the test. The data in the publication showed superior results for InteQuan compared to the existing quantification method, SISQuan.

"Prior to the launch of Xpresys Lung, MRM mass spec had been seen as promising but technically challenging to bring into the clinic," said Paul Kearney Ph.D., co-founder, chief science officer and president, Indi -- and senior author of the article. "These variability controls and the InteQuan method are one of several technical innovations Indi developed for use in its clinical laboratory prior to bringing Xpresys Lung to market. We hope these innovations will pave the way for other proteomic tests."

Xpresys Lung is a non-invasive, clinical laboratory-based, molecular blood test service designed to help physicians identify benign lung nodules with high probability. A recent clinical validation study of the laboratory-developed test showed when the test indicates a nodule is likely benign, the result is correct between 84 and 98 percent of the time -- with each nodule receiving an individual score based on its molecular signature.

"InteQuan is a simple yet robust quantification method for mass spec-based quantitative proteomics, especially for applications in biomarker research and in routine clinical testing," said Xiao-jun Li, Ph.D., senior director of bioinformatics, research and development, Indi -- and lead author of the paper. "We are actively using this method in our clinical laboratory and in our ongoing research. We hope it will also be useful to others in the field."

Xpresys Lung is also supported by a landmark clinical validation study published in The Journal of Thoracic Oncology in January 2015 and two studies published in Science Translational Medicine in October 2013. Click here to access the STM study.

About Indi

Indi (Integrated Diagnostics) is redefining molecular diagnostics and creating powerful new tools for physicians to non-invasively assess and more effectively manage complex diseases to improve patient outcomes, reduce complications, and lessen costs to the healthcare system. With the company's first breakthrough test, Xpresys Lung, which measures multiple blood proteins and identifies lung nodules with a high probability of being benign, physicians have the potential to reduce risks and the need for unnecessary invasive procedures.

The company was co-founded in October 2009 by systems-biology pioneer Dr. Lee Hood, who recently received the National Medal of Science from the U.S. government. His groundbreaking research is based on a systems biology approach, which measures hundreds of protein biomarkers found in blood to report on the physiological state of the body's 50 major organs, such as the lungs.

Backers include Baird Capital, InterWest Partners, Life Sciences Alternative Financing and the Wellcome Trust. Foundational intellectual property is exclusively licensed from the Institute for Systems Biology and Caltech. Learn more at

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