Launching a Novel Preclinical Infrastructure: Comparative Oncology Trials Consortium Directed Therapeutic Targeting of TNFα to Cancer Vasculature

Melissa C. Paoloni, National Cancer Institute
Anita Tandle, National Cancer Institute
Christina Mazcko, National Cancer Institute
Engy Hanna, National Cancer Institute
Stefan Kachala, National Cancer Institute
Amy LeBlanc, University of Tennessee
Shelley Newman, University of Tennessee
David Vail, University of Wisconsin
Carolyn Henry, University of Missouri
Douglass Thamm, Colorado State University
Karin Sorenmo, University of Pennsylvania
Amin Hajitou, Imperial College
Renata Pasqualini, University of Texas
Wadih Arap, University of Texas
Chand Khanna, National Cancer Institute
Steven K. Libutti, National Cancer Institute

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Published in PLoS ONE Vol. 4, No. 3, March 2009.

Abstract

Background: Under the direction and sponsorship of the National Cancer Institute, we report on the first pre-clinical trial of the Comparative Oncology Trials Consortium (COTC). The COTC is a novel infrastructure to integrate cancers that naturally develop in pet dogs into the development path of new human drugs. Trials are designed to address questions challenging in conventional preclinical models and early phase human trials. Large animal spontaneous cancer models can be a valuable addition to successful studies of cancer biology and novel therapeutic drug, imaging and device development.

Methodology/Principal Findings: Through this established infrastructure, the first trial of the COTC (COTC001) evaluated a targeted AAV-phage vector delivering tumor necrosis factor (RGD-A-TNF) to αV integrins on tumor endothelium. Trial progress and data was reviewed contemporaneously using a web-enabled electronic reporting system developed for the consortium. Dose-escalation in cohorts of 3 dogs (n = 24) determined an optimal safe dose (5 x 10¹² transducing units intravenous) of RGD-A-TNF. This demonstrated selective targeting of tumor-associated vasculature and sparing of normal tissues assessed via serial biopsy of both tumor and normal tissue. Repetitive dosing in a cohort of 14 dogs, at the defined optimal dose, was well tolerated and led to objective tumor regression in two dogs (14%), stable disease in six (43%), and disease progression in six (43%) via Response Evaluation Criteria in Solid Tumors (RECIST).

Conclusions/Significance: The first study of the COTC has demonstrated the utility and efficiency of the established infrastructure to inform the development of new cancer drugs within large animal naturally occurring cancer models. The preclinical evaluation of RGD-A-TNF within this network provided valuable and necessary data to complete the design of first-in-man studies.