Response Genetics, Inc. (Nasdaq:RGDX), a company focused on the development and sale of molecular diagnostic tests for cancer, announced the availability of its ResponseDX: Gastric™ genetic test panel, a proprietary PCR-based diagnostic test. By analyzing the expression of genes that correlate with response to commonly used chemotherapy agents, physicians can better tailor treatment for their patients with gastric cancer and gastroesophageal (GE) junction cancer. Approximately 37,000 people diagnosed with cancer each year in the U.S. may benefit from ResponseDX: Gastric™ testing. This newest ResponseDX™ test is available nationwide through the company's national sales force.
"ResponseDX™ tests offer physicians and their patients an objective way to chart a course of therapy during a very stressful time - the period between diagnosis and the start of treatment," said Kathleen Danenberg, CEO and president of Response Genetics, Inc. "By personalizing care based on a tumor's genetic makeup-as opposed to the "one-size-fits-all" approach that has been the standard until now-patients can receive the drug most likely to benefit their unique situation."
ResponseDX: Gastric™ tests quantitatively analyze three genes: excision repair cross-complementing factor 1 (ERCC1), thymidylate synthase (TS) and human epidermal growth factor receptor 2 (HER2). ERCC1 gene expression is a molecular marker shown to correlate with sensitivity to platinum-based drugs such as cisplatin, carboplatin and oxaliplatin; TS gene expression is a biomarker for sensitivity to the drug 5- fluorouracil (5-FU), an inhibitor of DNA replication and a component of the combination 5-fluorouracil-folinic acid- oxaliplatin (FOLFOX); and HER2 is a marker for sensitivity to trastuzumab, which was recently shown to have activity in gastric cancer.1
Data from Response Genetics-sponsored studies and others show that in order for gastric cancer patients to derive the maximum benefit from FOLFOX therapy, expression of both ERCC1 and TS genes must be at specific levels. However, if either marker is below a specific threshold, other therapies are available as alternative options (e.g., FOLFIRI)2,3,4.
About ResponseDX™ Tests
Response Genetics has developed PCR-based genetic tests - ResponseDX tests- to help physicians make more informed therapeutic treatment decisions for patients with non-small cell lung cancer (NSCLC), gastric cancer and colorectal cancer. The proprietary ResponseDX™ panels include four key genes: excision repair cross-complementing factor 1 (ERCC1), thymidylate synthase (TS), human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor expression (EGFR). These test panels also include the analysis of EGFR gene mutations in NSCLC and K-ras (KRAS) gene mutations in colorectal cancer. Using ResponseDX™ testing, clinicians may make better treatment decisions by adopting a cost-effective panel approach.
Response Genetics' KRAS mutation analysis provides some of the fastest turnaround times in the industry and accurate results on the smallest biopsies - which benefits patients because, in many cases, no tissue samples other than the pre-treatment diagnostic biopsy will be required for the biomarker analysis. All tests use technology developed by Response Genetics to isolate RNA from formalin-fixed, paraffin-embedded (FFPE) archived tissue for quantitative RT-PCR analysis of gene expression and analyzed in RGI's CLIA-certified laboratory.
1. Van Cutsem E, et al. Efficacy results from the ToGA trial: a Phase III study of trastuzumab added to standard chemotherapy (CT) in first-line human epidermal growth factor receptor 2 (HER2)-positive advanced gastric cancer (GC). Presented at the 2009 annual meeting of the American Society of Clinical Oncology, May 29-June 2, 2009, Orlando, FL. Abstract LBA4509.
2. Shirota Y., et al. ERCC1 and Thymidylate Synthase mRNA Levels Predict Survival for Colorectal Cancer Patients Receiving Combination Oxaliplatin and Fluorouracil Chemotherapy. J Clin Oncol. Dec 1 2001:4298-4304.