Dec 11, 2010
New study reveals unexpected cross-reactivity of clinically validated HER2 antibody
University of Copenhagen, Faculty of Life Sciences and Dako, a Danish-based world leader in tissue-based cancer diagnostics, today present the results of a study of three clinically validated antibodies used for determining HER2-positive breast cancer patients. The results of the study show that the PATHWAY® antibody from Ventana Medical Systems cross-reacts with HER4. This could potentially lead to patients receiving a false HER2-positive breast cancer diagnosis.
Approximately 20 percent of breast cancer patients are HER2 positive and may benefit from being treated with Herceptin®. However, as the drug causes considerable side effects in some cases, consistent and accurate test results are crucial for responsible patient care. Unfortunately, inaccuracy in HER2 testing results remains a major issue and points to a need for further investigation of the available HER2 test systems.
Therefore, the aim of a recent study led by University of Copenhagen, Faculty of Life Sciences was to investigate the specificity of three clinically validated, commercially available HER2 antibody-based test systems.
The results of the study show that the three HER2 antibodies tested all reacted with HER2. HercepTest™ from Dako and Oracle® from Leica Microsystems did not cross-react with HER1, HER3 or HER4, whereas the PATHWAY® antibody from Ventana Medical Systems showed cross-reaction with HER4 in all three test methods (immunohistochemistry, Western blotting and competitive ELISA) applied. The results are being presented this week at the 33rd Annual San Antonio Breast Cancer Symposium in Texas, USA.
“This result is important, as it could explain some of the inconsistencies seen in comparative studies done on breast cancer tissues. Using antibodies which cross-react with HER4 when testing for HER2 may potentially lead to an incorrect diagnosis and worst case to a patient receiving the wrong treatment. The results of the study therefore warrant further investigation in clinical breast cancer samples,” says Hans Christian Pedersen, who is Manager IHC PharmDx at Dako and one of the co-authors of the scientific study.
Dako’s HercepTest™ was the first example in history of a diagnostic biomarker linked to a specific therapy. It is developed exclusively to aid pathologists in identifying breast cancer patients most likely to benefit from treatment with Herceptin®. Until today, more than 5 million breast cancer patients have been tested for HER2 status using HercepTest™. Recently, the intended use for HercepTest™ has been expanded to include patients with gastric cancer.
For more information about the study, please contact:
Hans Christian Pedersen
Manager IHC PharmDx
Ph. + 45 25 43 44 04
Dako, based in Denmark, is a global leader in tissue-based cancer diagnostics. Hospital and research laboratories worldwide use Dako’s know-how, reagents, instruments and software to make precise diagnoses and determine the most effective treatment for patients suffering from cancer. Employing more than 1000 people and being present in more than 80 countries, Dako covers essentially all of the anatomic pathology markets globally. Dako is owned by a private equity fund, EQT. www.dako.com