INNV-04. CONGENITAL SPINAL GLIOBLASTOMA WITH SUSTAINED RESPONSE TO TROPOMYOSIN RECEPTOR KINASE (TRK) INHIBITION: A CASE REPORT

Abstract

Abstract Large scale genomic efforts have shown that a significant percentage of infant high-grade gliomas (HGG) carry targetable gene fusions. Given the rarity of congenital spinal HGGs, little is known about the molecular features of these tumors and their response to treatment. We describe a case of a patient with congenital spinal glioblastoma. A full-term female infant with symmetric IUGR was noted to have weakness with little movement of her upper extremities. MRI of the spine showed an infiltrative and hemorrhagic intraspinal cervicothoracic neoplasm with a large hemorrhagic intramedullary component. A biopsy was done and revealed a high-grade glial neoplasm with pan-TRK expression. Next generation sequencing (NGS) confirmed a MEF2D-NTRK1 gene fusion. Prior to the result of her molecular testing, the patient clinically deteriorated with decreased movement and increased apneic episodes despite steroid treatment. She was then started on treatment with carboplatin and etoposide per Macy et al 1. After one cycle of chemotherapy and given the results of NGS, targeted therapy with larotrectinib was added to her treatment. The patient showed a response (clinical and imaging) following cycle 1 with chemotherapy, and a marked response following cycle 2 with both chemotherapy and targeted TRK inhibition. The patient completed six cycles of chemotherapy and has continued on daily oral larotrectinib. She continues to tolerate the targeted therapy well and currently is 8 months old, growing and developing well. She has regained much of her movement and is eating and growing with apparent normal development. This case provides an example of a patient with congenital glioblastoma with TRK gene fusion that showed an impressive response to targeted therapy combined with more conventional chemotherapy. 1Macy M, et al. Clinical and molecular characteristics of congenital glioblastoma. Neuro Oncol. Jul;14 (7) 931–941, 2012).