Inclusion Criteria:

- Subject must have histologically confirmed anaplastic astrocytoma on the tentorium at
first relapse, and satisfy the following:

- unequivocal evidence of tumor recurrence or aggravation by MRI scan after
treatment for initial onset; the lesions must be measurable;

- anaplastic astrocytoma diagnosed histologically by the last pathological
diagnostic tests (including initial diagnosis) prior to initial administration
of temozolomide;

- tissue samples available for Central Pathologic Reviewer;

- pathologic diagnosis report by the study-conducting medical institution must be
available for the sponsor.

- MRI-related criteria:

- MRI scan performed within 14 days before initial temozolomide administration;

- assessable tumor site confirmed by MRI;

- dosage of steroidal agents not increased within 7 days before MRI prior to
initial temozolomide administration, except for postoperative subjects for first
relapse;

- MRI performed at the Principal Investigator's study location or designated
radiology facility during the study.

- Age >=18 years, either sex, inpatients or outpatients.

- Use of medically approved contraception methods in fertile subjects.

- Karnofsky performance status >=70.

- Adequate clinically laboratory values obtained within 14 days before initial
temozolomide administration.

- Criteria regarding treatment of initial onset:

- tumor biopsy, regardless of tumor resection at initial diagnosis;

- prior radiation therapy;

- prior chemotherapy with up to one nitrosourea-containing regimen.

- Tumor may or may not have been surgically resected at first relapse, but residual
measurable disease is required.

- For subjects who had surgical resection of tumor at first relapse:

- MRI scan must have been performed within 72 hours after surgery.

- the dose of steroidal agents must be reduced before temozolomide administration.

- Life expectancy >=12 weeks.

- Written informed consent obtained.

Exclusion Criteria:

- History of treatment with dacarbazine.

- Subjects who received chemotherapy within 6 weeks before initial temozolomide
administration.

- Subjects who received interstitial radiotherapy or stereotactic radiosurgery.

- Subjects who completed radiotherapy within 12 weeks before initial temozolomide
administration.

- Surgery at first relapse (including biopsy) within 1 week before initial temozolomide
administration.

- Subjects not recovered from acute toxicity due to previous therapy.

- High-risk subjects with complication of diseases other than malignant tumor, or who
require systemic administration of antibiotics for infection.

- Previous or concurrent malignancies at other sites.

- Pregnant or nursing women.

- Women of childbearing potential not using an effective method of contraception.

- Subjects previously treated with temozolomide.

- Participation in an ongoing clinical study, or in other clinical studies within 6
months before initial temozolomide administration.

- Subjects found inappropriate for the study by the investigator or subinvestigator.