-  INCLUSION CRITERIA:

          -  Patients must have recurrent glioma (histologically confirmed by NIH Laboratory of
             Pathology) with IDH1 or IDH2 mutation (confirmed by DNA sequencing, FoundationOne is
             preferable for confirmation of mutation, but not necessary).

          -  Patients must have tumor specific mutational load (number of somatic mutations per
             exome) performed at NIH. Must have either result of previous NIH testing or must
             provide adequate tissue sample for testing.

          -  The tumor tissue (e.g. block or 15 unstained slides) must be available for molecular
             and immune profiling. Fresh or frozen tumor sample will be used if available, but not
             mandatory.

          -  Age greater than or equal to 18 years. Because no dosing or adverse event data are
             currently available on the use of nivolumab in patients <18 years of age, children are
             excluded from this study, but will be eligible for future pediatric trials.

          -  Patient must be able to tolerate an MRI study with intravenous gadolinium contrast.

          -  Karnofsky greater than or equal to 60%

          -  Patients must have adequate organ and marrow function as defined below:

               -  Absolute neutrophil count greater than or equal to 1,500/mcL

               -  Platelet Count greater than or equal to 100,000/MCL

               -  Hemoglobin greater than 9.0 g/dL (may be transfused to achieve this level)

               -  BUN less than or equal to 30 mg/dL and

               -  Serum creatinine less than or equal to 1.7 mg/dL

               -  Total bilirubin (except patients with Gilbert s Syndrome, who are eligible for
                  the study but exempt from the total bilirubin eligibility criterion) less than or
                  equal to 2.0 mg/dL

               -  ALT and AST less than or equal to 2.5x institutional upper limit of normal.

          -  The effects of nivolumab on the developing human fetus are unknown. For this reason,
             women of child-bearing potential and men must agree to use adequate contraception
             (hormonal or barrier method of birth control; abstinence) prior to study entry and for
             the duration of study participation and up to 5 months (women) and 7 months (men)
             after the last dose of the drug. Should a woman become pregnant or suspect she is
             pregnant while she or her partner is participating in this study, she should inform
             her treating physician immediately.

          -  The patient must be able to understand and be willing to sign a written informed
             consent document.

        EXCLUSION CRITERIA:

          -  Patients who are receiving any other investigational agents.

          -  Patients who have a history of receiving immune therapy, such as a vaccine therapy,
             dendritic cell vaccine or intracavitary or convectional enhanced delivery of therapy.

          -  History of allergic reactions attributed to compounds of similar chemical or biologic
             composition to nivolumab.

          -  History of severe hypersensitivity reaction to any monoclonal antibody.

          -  Prior invasive malignancy (except non-melanomatous skin cancer) unless disease free
             for a minimum of 3 years prior to initiation of study therapy.

          -  Patients with active autoimmune disease or history of autoimmune disease that might
             recur, which may affect vital organ function or require immune suppressive treatment
             including systemic corticosteroids. These include but are not limited to patients with
             a history of immune related neurologic disease, multiple sclerosis, autoimmune
             (demyelinating) neuropathy, Guillain-Barre syndrome or CIDP, myasthenia gravis;
             systemic autoimmune disease such as SLE, connective tissue diseases, scleroderma,
             inflammatory bowel disease (IBD), Crohn s, ulcerative colitis, hepatitis; and patients
             with a history of toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome, or
             phospholipid syndrome. Such diseases should be excluded because of the risk of
             recurrence or exacerbation of disease.

             --Of note, patients with vitiligo, endocrine deficiencies including thyroiditis
             managed with replacement hormones including physiologic corticosteroids are eligible.
             Patients with rheumatoid arthritis and other arthropathies, Sj(SqrRoot)(Delta)gren s
             syndrome and psoriasis controlled with topical medication and patients with positive
             serology, such as antinuclear antibodies (ANA), anti-thyroid antibodies should be
             evaluated for the presence of target organ involvement and potential need for systemic
             treatment but should otherwise be eligible.

          -  The patient must not be currently on a corticosteroid dose greater than physiologic
             replacement dosing defined as 30 mg of cortisone per day or its equivalent.

          -  Uncontrolled intercurrent illness including, but not limited to, ongoing or active
             infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
             arrhythmia, or psychiatric illness/social situations (within timeframes identified in
             the bullets below) that would limit compliance with study requirements.

          -  Known HIV-positive or acquired immune deficiency syndrome (AIDS) based upon current
             CDC definition; note, however, that HIV testing is not required for entry into this
             protocol. The need to exclude patients with AIDS is based on the lack of information
             regarding the safety of nivolumab in patients with active HIV infection

          -  Pregnant women are excluded from this study because nivolumab s potential for
             teratogenic or abortifacient effects is unknown. Because there is an unknown but
             potential risk for adverse events in nursing infants secondary to treatment of the
             mother with nivolumab, breastfeeding should be discontinued if the mother is treated
             with nivolumab.

          -  Known active, chronic or history of hepatitis infection.