HistoRx Inc announces that the US Patent and Trademark Office has granted a patent protecting the company’s methods for determining a cancer patient’s prognosis based on sub-cellular localization of biomarkers.

US Patent No. 7,709,222 is issued to Yale University and inventors David Rimm, Bob Camp, Mark Gustavson and Greg Tedeschi, and is exclusively licensed to HistoRx.

Use of tissue biomarkers to characterize a patient’s cancer is a crucial element of personalized cancer care. To improve patient survival rates, therapies in the oncology marketplace are being combined with predictive biomarkers to help select patients who will respond to specific drugs. The claims issued in HistoRx’s new patent pertain to quantification of thymidylate synthase (TS), a well-known enzyme, in sub-cellular compartments—that is, the nucleus vs. cytoplasm of tumor cells—and using the ratio to determine a patient’s prognosis and responsiveness to specific treatments. The results from this test can be used to prescribe currently available therapeutics, making the test immediately relevant to oncologists.

The invention was only possible through the use of HistoRx’s proprietary AQUA® technology to quantify TS in cellular compartments of tumor cells from patients with colon cancer. AQUA technology is an automated, quantitative IHC testing method that enables measurement of protein biomarkers in tissue as an aid to a pathologist’s diagnosis. Such precise determination of first, the location within the tumor cell and second, the amount in each location is not possible with conventional testing methods, such as standard immunohistochemistry (IHC).

AQUA analysis is used in cancer research by twenty leading academic centers worldwide, is part of the clinical development plans for more than ten drug candidates from major pharma companies, and has been cited in more than 90 peer-reviewed publications. The first use of AQUA technology in the clinical diagnostic setting is expected later in 2010 with the launch by Genoptix Inc of diagnostic tests based on AQUA technology licensed from HistoRx.

"This patent demonstrates AQUA technology’s superiority to IHC by quantifying the ratio of TS in two sub-cellular compartments to identify patients who will respond to common first line therapeutics," said Rana K. Gupta, CEO of HistoRx. "Secondly, other TS tests available today are not standardized to give physicians confidence in the biomarker. AQUA technology is the foundation for the next generation of protein biomarker tests, addressing the clinical need for reliable results and quantifying biomarkers in context of their location."

"The use of a quantitative expression ratio between cellular compartments is a novel approach that is currently only possible with AQUA technology and can provide enhanced prognostic and predictive information for oncologists treating colon cancer patients," stated one of the inventors, Dr. Mark Gustavson. "In addition, other proteins show differential cellular localization and the use of an expression ratio is applicable for development of other novel biomarkers for predicting outcome or therapeutic response."

Source: HistoRx