Abstract 3407: The italian personalized medicine program PREME for high-risk neuroblastoma

Abstract Background: In the era of precision medicine, the need for high-risk neuroblastoma (NB) patient-specific therapies is crucial. Methods: From November 2018 to February 2021, the Italian PeRsonalizEd MEdicine (PREME) program has enrolled 18 NB affected patients. Tumors and bone marrow-infiltrating NB cells underwent to histological (selection panel: CD45, CD56, TH, PHOX-2B, S100) and to flow cytometry (selection panel: CD45, CD56, GD2, B7-H3) immunophenotyping, respectively. The biological material was then used for: 1) DNA extraction for subsequent DNAseq (Whole Exome Sequencing, 100X mean coverage, or Deep Targeted Gene Panel Sequencing, 1000x mean coverage, when the percentage of the neoplastic counterpart within the sample was over or down 60%, respectively); 2) RNA extraction for subsequent RNAseq (30 millions of reads per sample); 3) Development of primary NB cell culture (3D/tumor-spheres) and of Patient-Derived Xenografts (PDX) models in mice (both stored in local Bio-banks). Results: 14 out of 18 patients (77.7%) had one or more potentially actionable somatic alterations in primary tumors. Among those, 4 had also one pathogenic germline variant in known cancer predisposition genes. In 11 of the 14 cases the Molecular Tumor Board identified molecular alterations potentially targetable by an approved or investigational agent, and 4 of those received the treatment. Out of 11 tumor samples implanted in mice, 5 gave rise to PDX, all preserved in a local PDX Bio-bank. Comparing all genomic variants of the 5 tumors with developed PDX samples up to second generation, we observed a high grade of similarity among primary tumors and subsequent PDX tumor models (Pearson coefficients>0.8). Considered the allele frequency distribution, a significant increase in the PDX tumor models at first generation (G1) (median=0.008) and second generations (G2) (median=0.038) with respect to the primary tumors (G0) (median=0.034) was observed. The validity and reproducibility of our PDX models was further demonstrated from high rates of conserved somatic variants at G1 compared to G0 tumors (mean=81.93%), at G2 compared to G1 (mean=84.04%) and at G2 compared to G0 tumors (mean=78.31%). Finally, we were able to identify all the potentially actionable genetic alterations of G0 tumors in the PDX generations G1 and G2. A high grade of similarity was confirmed when the histological, the immunophenotypic and the transcriptomic profiles among primary tumors and PDX generations were compared. Also, NB cells grown as 3D demonstrated good rates of conserved somatic variants, paving the way to the creation of a Bio-bank of patient-derived tumor-spheres. The development of a bioinformatics pipeline for RNAseq data analysis is ongoing. Conclusions: Until now, PREME program has reported a large number of NB patient samples, which harbor targetable genomic alterations and has allowed the development of a Bio-banks to be used for translational research. Citation Format: Mario Capasso, Chiara Brignole, Veronica Bensa, Vito Alessandro Lasorsa, Enrico Sebastiani, Sueva Cantalupo, Angela Rita Sementa, Katia Mazzocco, Barbara Cafferata, Valerio Gaetano Vellone, Michele Cilli, Enzo Calarco, Elena Giusto, Eleonora Ciampi, Patrizia Perri, Maria Valeria Corrias, Sanja Aveic, Doriana Fruci, Alessandro Quattrone, Annalisa Tondo, Roberto Luksch, Rossella Mura, Marco Rabusin, Francesco De Leonardis, Monica Cellini, Paola Coccia, Massimo Conte, Loredana Amoroso, Alberto Garaventa, Mirco Ponzoni, Fabio Pastorino. The italian personalized medicine program PREME for high-risk neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3407.