HGG-22. Uptake of investigational therapy in children with High Grade Glioma

High grade gliomas (HGG) in children carry a dismal prognosis. Standard therapy includes resection when possible, radiotherapy and sometimes the addition of temozolomide. There is no standard treatment for progression or relapse. Since November 2018 we have offered upfront molecular testing to all children with HGG who had biopsy/ resection. Testing was mainly done by next generation sequencing panel, and some had research based methylation profiling and RNA seq. We aimed to see whether families chose to receive additional investigational treatment as a result of the molecular testing results and whether the treatment involved participation in a clinical study, or whether treatment was compassionate. A total of 22 patients aged 2.8-16.8 years with HGG had a biopsy/resection over this three year period. Thirteen had diffuse midline glioma (DMG) of which 11 had the H3K27 mutation, and 9 were cortical. Six children had underlying predisposition syndromes: mismatch repair deficiency (n=3 proven + 1 highly suspected), neurofibromatosis1 (n=1), Li-Fraumeni (n=1). All the cortical gliomas had potential treatment options based on their molecular testing. 10/22 (45%) children received investigational therapy of which only three participated in a clinical study while the rest received compassionate therapy. Compassionate treatments included BRAF/MEK inhibitors (n=4), Larotrectinib (n=1), and immune checkpoint inhibitors (n=2). Of the 12 who did not receive investigational therapy, four, all cortical, have potential therapy options but are currently in remission. Of the remaining eight, two had very rapid clinical deterioration and died, and six (all DMG) did not wish/ were unable to travel abroad and no relevant clinical study was available locally. We conclude that the families of children with HGG are highly motivated to receive investigational therapy. Upfront molecular testing of these tumors, especially for cortical HGG, is imperative and there is a growing need for accessible clinical studies.