Efficacy of Nivolumab for Recurrent IDH Mutated High-Grade Gliomas

Inclusion Criteria:

1. Histological confirmation of grade III or IV high-grade glioma
2. Tumor is mutated for IDH1 or IDH2 gene (detected by R132HIDH immunochemistry orIDH1/IDH2 sequencing)
3. Age between 18 and 85 years old
4. Recurrence after radiotherapy and at least one line of alkylating chemotherapy (Temozolomide or PCV (Procarbazine, CCNU, Vincristine) (Surgery at recurrence isallowed before trial inclusion)
5. Recurrence occurring more than 12 weeks from the end of the radiotherapy or occurringoutside the irradiated volume
6. Karnofsky performance status > 50
7. Radiologically measurable disease based on RANO criteria. Tumor lesions situated in apreviously irradiated area are considered measurable if progression has beendemonstrated in such lesions
8. Patients must be able to taper steroids (preferably discontinued). Dose at inclusionmust be ≤ 10 mg prednisone (or equivalent*). The decrease in dose will be evaluated byclinical examination, the ability to decrease the corticosteroids being related to theabsence of increased headaches and the absence of increased of neurological disability (impaired alertness)
9. Available archived tissue for molecular (MGMT methylation, mutational load estimation)and immunohistochemical analysis (PD1, PD-L1, CD3, CD4, FoxP3, CD8, CD68, CD163, GFAP,olig2, ATRX, CIC, Ki67, P53)
10. The following laboratory values obtained ≤ 7 days prior to inclusion:

• WBC ≥ 2000/μL
• Neutrophils ≥ 1500/μL
• Platelets ≥ 100 x103/μL
• Hemoglobin > 9.0 g/dL
• Serum creatinine ≤ 1.5 x ULN or creatinine clearance (CrCl) ≥ 40 mL/min (if usingthe Cockcroft-Gault formula below): Female CrCl = [(140 - age in years) x weight in kg x 1.04] / serum creatinine in µmol/l Male CrCl = ([140 - age in years) x weight in kg x 1.23] / serum creatinine in µmol/l
• AST/ALT ≤ 3 x ULN
• Total Bilirubin ≤ 1.5 x ULN (except subjects with Gilbert Syndrome, who can havetotal bilirubin < 3.0 mg/dL)
• Negative serum pregnancy test for women of childbearing potential

11. Women of childbearing potential (WOCBP) must agree to follow instructions formethod(s) of contraception for the duration of study treatment with nivolumab and 5months after the last dose of study treatment (ie, 30 days (duration of ovulatorycycle) plus the time required for the investigational drug to undergo approximatelyfive half-lives)
12. Males who are sexually active with WOCBP must agree to follow instructions formethod(s) of contraception for the duration of study treatment with nivolumab and 7months after the last dose of study treatment {i.e., 90 days (duration of spermturnover) plus the time required for the investigational drug to undergo approximatelyfive half-lives.}
13. Written informed consent dated and signed, prior to any study specific procedures (sampling, treatment and analyses).
14. Affiliation to a French social security system (recipient or assign) excluding AME.

Exclusion Criteria:

1. Pregnant or breastfeeding women
2. Any serious or uncontrolled medical disorder that, in the opinion of the investigator,may increase the risk associated with study participation or study drugadministration, impair the ability of the subject to receive protocol therapy, orinterfere with the interpretation of study results
3. Prior treatment with an anti-PD-1, anti-PD-L1, anti-PD-L2, anti-CD137, anti-CTLA-4antibody or any other antibody or drug specifically targeting T-cell co-stimulation orimmune checkpoint pathways
4. Subjects with an active, known or suspected autoimmune disease. Subjects with type Idiabetes mellitus, hypothyroidism only requiring hormone replacement, skin disorders (such as vitiligo, psoriasis or alopecia) not requiring systemic treatment, orconditions not expected to recur in the absence of an external trigger are permittedto enrol
5. Subjects with interstitial lung disease that is symptomatic or may interfere with thedetection or management of suspected drug-related pulmonary toxicity or congestivecardiac insufficiency
6. Any positive test for hepatitis B virus or hepatitis C virus indicating acute orchronic infection, and/or detectable virus and a known history of positive test forhuman immunodeficiency virus (HIV) or known acquired immunodeficiency syndrome (AIDS).
7. Subjects with a condition requiring systemic treatment with either corticosteroids (> 10 mg daily prednisone or > 1,5 mg dexamethasone or equivalent*) or otherimmunosuppressive medications within 14 days of first study treatment administration.Inhaled or topical steroids, and adrenal replacement steroid doses > 10 mg dailyprednisone or > 1,5 mg dexamethasone or equivalent, are permitted in the absence ofactive autoimmune disease.
8. Any chemotherapy, anticancer immunotherapy or anticancer agents within 4 weeks (6weeks for nitrosourea) before the first dose of study treatment,
9. Receiving any other investigational agent or study drugs from a previous clinicalstudy within 4 weeks before the first dose of study treatment (6 weeks fornitrosoureas).
10. Prior malignancy active within the previous 3 years except for locally curable cancersthat have been apparently cured, such as basal or squamous cell skin cancer,superficial bladder cancer, or carcinoma in situ of the prostate, cervix, or breast.
11. History of allergy or Hypersensitivity to Nivolumab or to any of the excipients
12. Any unresolved toxicities (excepted alopecia), from prior therapy greater than CTCAEgrade 1 at the time of inclusion.
13. Subjects with history of life-threatening toxicity, including hypersensitivityreaction, related to prior immunoglobulin treatment for another condition (exceptthose considered unlikely to re-occur) or any other study drug component.
14. Surgical procedure < 7 days prior to first study treatment administration, vascularaccess device no restriction;
15. Subjects unable (e.g., due to pacemaker or ICD device) or unwilling to have acontrast-enhanced MRI of the head;
16. Known allergy or contraindication to Gadolinium;
17. Patients under guardianship