Abstract 5469: ITCC-P4, a preclinical proof-of-concept drug testing platform as a tool for pharmacological screening in pediatric tumor models

Abstract Cancer remains the main cause of disease-related death in childhood. Pediatric tumors are characterized by a low mutational burden and high intertumoral heterogeneity, with multiple subtypes compared to their adult counterparts. The lack of access to many innovative therapies remains one of the main challenges in the pediatric oncology, especially for the 25% of patients who experience relapses. In this context, the need for the development of a well characterized collection of pediatric models, to provide large scale preclinical testing, is capital for the subsequent identification and prioritization of promising novel therapeutic options. The EU funded “Innovative Therapies for Children with Cancer-Pediatric Preclinical Proof-of-Concept Platform” (ITCC-P4) consortium is a unique public-private collaborative project consisting of academic and industrial partners that aimed at establishing a collection of 400 patient-derived xenograft (PDX) models representing the most common high-risk pediatric cancers. The project involved various aspects of model development including the thorough molecular and pharmacological characterization. XenTech’s participation was focused on the development and preclinical in vivo drug testing of Ewing sarcoma (n=17), hepatoblastoma (n=10), rhabdoid tumors (n=6), synovial sarcoma (n=2), rhabdomyosarcoma (n=2) and other tumors (n=6), as part of overall cohort. PDXs were obtained by transplantation of post-surgery tumor specimens, either by grafting tumor fragments into the interscapular region or subcutaneously in the right flank of nude, NOD-Scid or NOD-Scid gamma mice. Tumor xenografts were amplified by serial transplantation, and tissue samples were retained at early passages for molecular characterization. Fragments from established PDX models where frozen to generate a revivable ITCC-P4 PDX collection. Then, proof-of-concept drug testing was conducted, in a single mouse trial format: each tumor type (n=X PDX models) was treated with a dedicated panel of Standard-of-Care (SoC;n=3) and novel targeted therapies (n=6), or combinations of 2 or 3 novel targeted therapies; for each PDX model n=1 mouse being included per treatment. All molecular and drug-testing data obtained by the different partners are being centralized in the R2 repository (https: //r2. amc. nl), providing a powerful tool for data integration, visualization and interpretation of the results. A unique collection of well characterized pediatric PDX models derived from the most relevant pediatric tumor types was enabled by a strong public-private collaborative project. This large cohort is now available for preclinical testing of novel therapeutic agents within a non-for-profit spinoff company, ITCC-P4 gGmbH (www. itccp4. com), offering new perspectives to the identification of promising treatment options for children with cancer. Citation Format: Emilie Indersie, Sophie Branchereau, Brice Fresneau, Christophe Chardot, Didier Surdez, Alexandra Saint-Charles, Maria Eugénia Marques da Costa, Ángel M. Carcaboso, Katia Scotlandi, Massimo Moro, Heinrich Kovar, Jan-Henning Klusmann, Klaus-Michael Debatin, Simon Bomken, Louis Chesler, Chris Jones, Beat Schäfer, Marco Wachtel, Johannes Gojo, Walter Berger, Christina Guttke, Maureen Hattersley, Frédéric Colland, Ashley Strougo, Dennis Gürgen, Jens Hoffmann, Julia Schueler, Pablo M. Aviles, María José Guillén, Aniello Federico, Apurva Gopisetty, Justyna Anna Wierzbinska, Andreas Schlicker, Sara Colombetti, Olaf Heidenreich, Fatima Iradier, Nicole Huebener, Natalie Jäger, Jan Koster, Marcel Kool, Gudrun Schleiermacher, Jan J. Molenaar, Birgit Geoerger, David J. Shields, Hubert N. Caron, Louis F. Stancato, Stefan M. Pfister, Gilles Vassal, Eva-Maria Rief, Olivier Déas. ITCC-P4, a preclinical proof-of-concept drug testing platform as a tool for pharmacological screening in pediatric tumor models abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 5469.