Safety and efficacy of temozolomide in patients with recurrent anaplastic oligodendrogliomas after standard radiotherapy and chemotherapy

Purpose: Most primary oligodendrogliomas and mixed gliomas (oligoastrocytoma) respond to treatment with procarbazine, lomustine, and vincristine (PCV), with response rates of approximately 80%. However, limited data on second-line treatments are available in patients with recurrent tumors. A novel second-generation alkylating agent, temozolomide, has recently demonstrated efficacy and safety in patients with recurrent glioblastoma multiforme and anaplastic astrocytoma. This study describes the effects of temozolomide in patients with recurrent anaplastic oligodendroglioma (AO) and anaplastic mixed oligoastrocytoma (AOA). Patients and Methods: Forty-eight patients with histologically confirmed AO or AOA who had received previous PCV chemotherapy were treated with temozolomide (150 to 200 mg/m(2)/d for 5 days per 28-day cycle). The primary end point was objective response. Secondary end points included progression-free survival (PFS), time to progression, overall survival (OS), safety, and tolerability. Results: Eight patients (16.7%) experienced a complete response, 13 patients (27.1%) experienced a partial response (objective response rate, 43.8%), and 19 patients (39.6%) experienced stable disease. For the entire treatment group, median PFS was 6.7 months and median QS was 10 months. For objective responders, median PFS was 13.1 months and median OS was 16 months. For complete responders, PFS was more than 11.8 months and OS was more than 26 months. Response correlated with improved survival. Temozolomide was safe and well tolerated. Twelve patients developed grade 1/2 thrombocytopenia and three patients developed grade 3/4 thrombocytopenia. Conclusion: Temozolomide is safe and effective in the treatment of recurrent AO and AOA. J Clin Oncol 19:2449-2455. (C) 2001 by American Society of Clinical Oncology.