Response Genetics' clinical approaches to improve cancer care to be presented at ASCO 2011

Response Genetics, Inc. (Nasdaq:RGDX), a company focused on the development and sale of molecular diagnostic tests for cancer, announced today five presentations to be held during the 2011 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, IL from June 3 to June 7, 2011. Study results are based in part on the company's proprietary technology and approach.

“The results to be presented at ASCO 2011 are the product of Response Genetics' commitment to finding new ways to help patients and to personalize cancer care”

Data will highlight clinical results in non-small cell lung cancer (NSCLC) and esophageal cancer and approaches to improve cancer care.

"The results to be presented at ASCO 2011 are the product of Response Genetics' commitment to finding new ways to help patients and to personalize cancer care," said Kathleen Danenberg, CEO of Response Genetics. "Through scientific and clinical collaborations we are applying our powerful technology to identify lung cancer patients likely to benefit from new and existing therapies and to investigate the use of predictive and prognostic markers in the treatment of esophageal cancers."

All studies presented used technology developed by Response Genetics to isolate RNA from formalin-fixed, paraffin-embedded (FFPE) archived tissue for quantitative RT-PCR analysis of gene expression. Following is a summary of presentations:

Poster Discussion Sections

Saturday June 4, 5:00 p.m. to 6:00 p.m. CT., S 100bc

Abstract No. 10520: Large-scale screening of ALK fusion oncogene transcripts in archival NSCLC tumor specimens using multiplexed RT-PCR assays.

A panel of single and multiplexed RT-PCR assays capable of detecting all nine known EML4-ALK fusion gene transcripts and ALK RNA level variants was used to identify ALK-positive patients and to investigate the impact of crizotinib on tumor sensitivity to chemotherapy. Of the 1,889 NSCLC specimens tested, 75 (4.0 percent) were EML4-ALK positive - all were adenocarcinomas and none harbored EGFR or K-Ras mutations. This unique approach allows the rapid, large-scale screening of NSCLC tissues for ALK fusion gene transcripts.

Monday June 6, 5:00 p.m. to 6:00 p.m. CT, Hall D2

Abstract No. 7530: Use of negative TTF-1 status to predict for negative EGFR mutations status with a high negative predictive value in patients with adenocarcinomas of the lung.

Archival specimens from patients with NSCLC were tested for EGFR mutations by allele-specific PCR; TTF-1 status was determined by examining patients' pathology reports. Of the 693 specimens tested, TTF-1 status was known in 301, and of those, 224 (74 percent) harbored EGFR mutations - only two of the EGFR mutation-positive specimens were TTF-1 negative and 28 of the 77 EGFR wild type specimens were TTF-1 negative. As TTF-1-negative lung adenocarcinomas have a 99 percent probability of also being negative for EGFR mutations, results suggest the benefit of initiating chemotherapy treatment in the 30 percent of patients who test positive for TTF-1 as their EGFR mutation status is verified.

Monday June 6, 5:00 p.m. to 6:00 p.m. CT, Hall D1

Abstract No. 4023: Association of ERCC1 gene expression with outcome in stage II-III esophageal adenocarcinoma patients treated with preoperative platinum-based chemoradiation in a phase II cooperative group study (SWOG S0356).

Expression of genes associated with drug metabolism (DPD, GSTPi, TS and TP) and DNA repair (ERCC1 and XPD) were tested to determine their association with clinical outcome in esophageal cancer. Thirteen polymorphisms in drug metabolism (GSTP, MTHFR and TS) and DNA repair (ERCC1, RAD51, XPD, XRCC1 and XRCC3) genes were also investigated to determine if specific patterns were predictive. In a univariate analysis of data derived from 92 patients, only ERCC1 gene expression levels were associated significantly with progression-free survival and overall survival, with high ERCC1 levels were predictive of lower two-year progression-free survival (17 versus 67 percent,>

General Poster Sections

Saturday June 4, 2:00 p.m. to 6:00 p.m. CT, Hall A

Abstract No. 7056: BRCA1 mRNA expression patterns in a large lung cancer cohort.

In lung cancer, low expression of the DNA repair gene ERCC1 is associated with platinum responsiveness. Expression of a second important DNA repair gene, BRCA1, was quantified in NSCLC tumor samples to determine potential regulatory relationships between the genes and to tumor histology and patient demographics. Of the 425 tumor specimens tested, no association was observed between either gene and patient age or gender. A significant association with histology, however, was identified - media BRCA1 gene expression was higher in squamous cell versus adenocarcinoma (2.39 versus 0.57; P<0.0001). A small but statistically significant positive correlation was also seen between BRCA1 and ERCC1 expression (P<0.001).

Monday June 6, 8:00 a.m. to noon CT., Hall A

Abstract No. 4023: Integrated research platform (iGXT) for enhancing drug development and personalizing cancer therapy: Pilot study results.

A unique approach was taken to test the feasibility of integrating data derived from multiple research models to optimize drug development and treatment strategies. Preclinical data from two mouse models - one possessing tumors with defined EGFR-related characteristics and a second hosting NSCLC patient-derived xenografts - were tested for molecular targets of interest. Information from these and other sources were used to validate the approach and to extrapolate back to individual patient information. Findings from this study may help advance understanding of intra-patient tumor differences to improve personalized cancer therapy.