Study of DS-1001b in Patients With Gene IDH1-Mutated Gliomas

Inclusion Criteria: 1. Has histologically confirmed glioma with an IDH1-R132 mutation 2. Has disease that has recurred or progressed following standard treatment including radiotherapy 3. Has measurable lesion(s) as per RANO criteria 4. Has Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2 Exclusion Criteria: 1. Has significant symptoms of increased intracranial pressure 2. Has another active neoplasm 3. Has active infection requiring systemic treatment 4. Has a history of severe cardiac disease 5. Has had prior treatment with any inhibitor targeting mutant IDH1 6. Has had investigational drug treatment within 4 weeks prior to the first dose of study treatment 7. Is a pregnant or lactating female