In:
Cancer Research, American Association for Cancer Research (AACR), Vol. 73, No. 8_Supplement ( 2013-04-15), p. 2389-2389
Abstract:
Background: In this ongoing clinical exploratory study, FFPE tissue sections are probed for protein biomarkers along the PI3K/Akt/mTOR pathway. A panel of assays was developed using Layered Immunohistochemistry (L-IHC). L-IHC allows for concurrent measurement of 6-8 proteins (total and/or phosphorylation sites) using a single tissue section. The goal was to discover applications of the technique based on complementary rationales about the implications of pathway activation. Those were: 1) in a scenario where the test indicates drug target activation, analysis for a positive response to an mTOR-targeted tyrosine kinase inhibitor (everolimus and/or temsirolimus) in kidney cancer; or 2) analysis for predicting no response to a HER2-targeted drug (trastuzumab) in breast cancer, assuming a scenario where the test would indicate activation of a functional by-pass pathway. Methods: FFPE pre-treatment tissue samples from patients (pts) with advanced renal cell carcinoma (aRCC) treated with temsirolimus and/or everolimus, and trastuzumab treated HER2-positive breast cancer pts were studied. In L-IHC tissue-transfer layers, the intensity of specific protein biomarker signals in the cancer regions is visually scored. The expression levels are then summed and correlated with the patient's clinical outcome status. Results: In the trastuzumab study, four biomarkers were determined to correlate with patient response. A total of 32 responders and 13 non-responders have been analyzed to date. The sum score for a 4-biomarker panel discriminated between responders and non-responders. The test correctly identified 28/32 responders and 10/13 non-responders for a sensitivity of 87%, specificity of 76%, and an accuracy of 81%. In the mTOR inhibitor study, 35 RCC cases were analyzed, and a composite score based on 6 biomarkers was found to correlate to patient response. 11/14 OR/SD pts (sensitivity 79%) and 18/21 PD pts (specificity 86%). Conclusions: These results indicate that multiplexed protein analysis of tumor tissue is capable of providing scenario-specific information, which could help guide targeted therapy with either a positive or a negative clinical significance. Funding source: Supported in part by NCI Grant 5R44CA123994-06 and by 20/20 GeneSystems. Citation Format: Alexandrine Derrien-Colemyn, Soon Park, John Gillespie, Michael Lebowitz, Peter Tunon. Positive or negative clinical implications of PI3K/Akt/mTOR pathway activation for predicting patient response to targeted therapy using multiplexed protein imaging of tumor tissue. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2389. doi:10.1158/1538-7445.AM2013-2389
Type of Medium:
Online Resource
ISSN:
0008-5472
,
1538-7445
DOI:
10.1158/1538-7445.AM2013-2389
Language:
English
Publisher:
American Association for Cancer Research (AACR)
Publication Date:
2013
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2036785-5
detail.hit.zdb_id:
1432-1
detail.hit.zdb_id:
410466-3
