INNV-53. Precision Medicine in Pediatric Neuro-Oncology-Experience from a tertiary care center in Canada

Abstract INTRODUCTION The increased use of multi-omics testing in Neuro-Oncology has provided newer therapeutic options directed against molecular alterations for the treatment of Pediatric brain tumors, referred to as Precision medicine with targeted therapy (TT). We describe here the real-world use of innovative /targeted therapies for pediatric brain tumors from Cancer Care Manitoba in Canada. METHODS This is a retrospective study of all pediatric brain tumors diagnosed between 2010-2023 treated with at least one dose of TT. RESULTS Forty patients were treated with 50 lines of TT; Seven patients (N=7/40, 17.5%) received multiple lines of TT. Low grade gliomas (LGG) formed the largest cohort (N=26/40, 59.1%). Initial treatment included surgery (N=12/40, 30%), chemotherapy (N=15/40, 37.5%), radiotherapy (N=10/40, 25%) or any combination of the three modalities (N=9/40, 22.5%). Twenty-seven (N=27/50, 54%) patients were initiated with TT before first relapse. TT was initiated in 55% of the patients (N=22/40) based on molecular findings. Targetable genomic alterations were found mostly in RAS/MAPK and PI3K/AKT/mTOR pathway. Monotherapy with MEK inhibitors (Trametinib, Selumetinib, N=30/50, 60%) was the most common regime; 12 different combinations of TT were used; most common being Dabrafenib and Trametinib. Drugs were accessed through compassionate access programs in 94% of cases (N=47/50). Among all patients treated with TT, ten (N=10/50, 20%) had partial response and 28 (N=29/50, 63.6%) had stable disease; 11 patients (11/50, 22%) had progression while on TT; leading to a disease control rate (DCR) of 78% and a clinical benefit rate (CBR) of 63.3%. Adverse events involved most commonly the skin, hair and /nails (N=24, 66.7%). TT was stopped due to toxicities in 6 patients (N=6/50, 12%) with no deaths reported. CONCLUSION Our study confirms existing data in the literature regarding precision medicine in pediatric cancer with high CBR along with good quality of life and minimal toxicities.