The purpose of this pilot study is that exosomes constitute a more interesting support for analyzes allowing a broader screening of molecular alterations to be carried out with more reliable, more sensitive and more efficient results than the reference Foundation One Liquid CDx test.

Gliomas are the most common primary brain tumors in adults. The heterogeneity of tumors, the lack of reliable criteria for identifying different subtypes make their histopathological diagnosis and their management complex. The molecular profiling from circulating exosomes is one of the most promising approaches to better characterize gliomas.

We will demonstrate the superiority of detection by NGS of molecular abnormalities present in exosomes from glioblastomas, compared to detection by the Foundation One Liquid CDx test on ctDNA.

Inclusion Criteria:

• Subject of both sexes at least 18 years of age with glioblastoma.
• Patient for whom an FMI test is indicated, progressing after a 1st line following the chemotherapy and radiotherapy protocol (STUPP protocol)
• Patient affiliated to French social security

Exclusion Criteria:

• Patient included in another research protocol using an experimental molecule.
• Any medical or psychiatric condition which, in the Investigator's opinion, would preclude the patient from adhering to the protocol or completing the study per protocol
• Patient under legal protection, guardianship or curatorship
• Patient with active malignancy or a previous malignancy within the past 5 years; except for patient with resected Basocarcinoma and resected carcinoma in-situ of the cervix.