Abstract 1186: Creating clinical target validation groups via quality assured transfer of robust clinical pharmacodynamic (PD) assays from the NCI: clinical implementation of a HIF1α immunoassay in tumor biopsies.
Authors: Ralph E. Parchment, Robert J. Kinders, Sook Ryun Park, Katherine V. Ferry-Galow, Yvonne A. Evrard, Jiuping Ji, Shivaani Kummar, Joseph E. Tomaszewski, James H. Doroshow
Journal: Cancer Research (2013)

Abstract Robust pharmacodynamic (PD) assay results are valuable for informing go/no-go decisions about preclinical and clinical development of new agents and for identifying optimal combinations of targeted agents. The NCI's Division of Cancer Treatment and Diagnosis (DCTD) develops and validates PD assays to obtain accurate information about target engagement in first-in-human clinical trials. The Pharmacodynamic Assay Development and Implementation Section (PADIS) and National Clinical Target Validation Laboratory (NCTVL) were established at SAIC-Frederick to develop and validate PD assays by validating analytical performance, demonstrating fitness-for-purpose for the clinical protocol, and finalizing companion standard operating procedures (SOPs) for specimen handling and processing. Proven clinical assays are transferred from the NCI to requesting sites in academia and industry through laboratory-based certification and training, centralized access to current SOPs, assistance with assay transfer, and participation in the assay's Quality Assurance Plan. One such validated assay is the HIF1α Immunoassay, which is currently in clinical evaluation at NCTVL. Procedures to clinically implement HIF1α analysis in tumor biopsies from patients treated with angiogenesis inhibitors required consideration of many factors including the low abundance and oxygen sensitivity of the analyte. A customized extraction process for HIF1α was developed and optimized using mouse xenograft biopsies. Use of a customized extraction buffer containing 2-hydroxyglutarate, which was degassed to minimize dissolved oxygen, was shown to improve analyte recovery. Optimized extraction procedures also include use of an automated ceramic bead homogenizer to improve both the efficiency and reproducibility of extraction of HIF1α over sonication. The immunoassay procedure uses lyophilized reagents from a commercially available kit and a modified procedure together with quality control specimens that serve to qualify the performance of each run. Finally, pre-defined data analyses and quality control evaluation criteria are used to perform a semi-automated process to analyze data and evaluate acceptability of performance for both the assay run and individual clinical specimens. In total, five SOPs have been developed to define procedures from collection and freezing of the needle biopsies in the radiology suite to data analyses and reporting. Together, these defined procedures are being used to perform PD analyses as key parts of two clinical trial evaluations at the NCI and will be launched to the community once clinical utility is demonstrated. Funded by NCI Contract No HHSN261200800001E. Citation Format: Ralph E. Parchment, Robert J. Kinders, Sook Ryun Park, Katherine V. Ferry-Galow, Yvonne A. Evrard, Jiuping Ji, Shivaani Kummar, Joseph E. Tomaszewski, James H. Doroshow. Creating clinical target validation groups via quality assured transfer of robust clinical pharmacodynamic (PD) assays from the NCI: clinical implementation of a HIF1α immunoassay in tumor biopsies. [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 1186. doi:10.1158/1538-7445.AM2013-1186