Abnova and Japan National Cancer Center File Patent on Ovarian Cancer Prognosis and Companion Diagnostic Biomarker for Personalized Therapy

Neihu, Taiwan (September 09, 2010)

Abnova Corporation and Japan National Cancer Center Research Institute have jointly filed an international patent covering a novel protein, Cystathionine gamma-Lyase, CTH, relating to ovarian cancer prognosis, companion diagnosis and therapy. This is the result of a collaborative work screening a large collection monoclonal antibodies on ovarian cancer tissue specimens, confirming protein biomarker with strongest statistical correlation to disease prognosis in both multiple and independent patient cohorts, and validating its utility as therapeutic target in vitro. With the advent of personalized medicine, biotech and pharmaceutical industries are mandated to develop more efficacious drugs based on protein phenotype diagnosis of the patient. The feasibility of this new paradigm can be seen in the commercial success of companion diagnostics such as HER2 protein marker for Herceptin monoclonal antibody therapy and EGFR mutation for ERISSA chemotherapy. Leveraging the same par adigm, Abnova prepares to develop the CTH into a full-fledge, in vitro diagnostic (IVD) biomarker not only to identify the subset of ovarian cancer patients with poor prognosis but also provide a focused drug target for more effective personalized treatment. The timing of this IVD application is in line with Abnova's scheduled ISO13485 completion this year as a prerequisite for diagnostic product development.

Ovarian cancer is the second most common gynecological cancer and fifth most common cause of cancer death in women. Ovarian cancer does not usually cause symptom until it has enlarged or spread. Hence, patients usually present with more advanced tumor stage at the time of diagnosis. At such, surgery is often needed to debulk the tumor followed by chemotherapy. Notably, overexpression of CTH protein in ovarian cancer tissue prior to drug therapy is significantly correlated with worse prognosis according to our study. The expression of CTH protein can be analy zed via a simple yet powerful immunohistochemical technique using a monoclonal antibody on formalin-fixed, paraffin-embedded tissue taken from patient at the time of biopsy or after surgery. Moreover, platinum-based chemotherapy such as carboplatin is invariably given to majority of patients as first-line treatment with an estimated $500M USD global market in an attempt to remove any remaining tumor after the surgery. However, platinum-based drug resistance is a serious problem which occurs in 70-80 percent of the ovarian cancer patients. We have observed that concurrent inhibition of CTH enzyme in a simulated CTH overexpressed tumor cell significantly augments the efficacy of platinum-based treatment. Additional experiments are underway to replicate the tumor cell results on animal model, as a predecessor for consideration and development of CTH targeted therapy in human. These combined findings and the utility of CTH as a biomarker for ovarian cancer will be published befo re end of this year. Abnova has also started to source potential drug inhibitor candidates of CTH which can be utilized in humans.

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