Protracted administration of low doses of temozolomide (TMZ) in the treatment of relapse glioblastoma (GBM) enhances the antitumor activity of this agent

1572 Background: The efficacy of temozolomide (TMZ) is strictly related to the possibility to reach and maintain high and prolonged cellular drug concentrations in the target tissue. Evidence exists demonstrating that the achievement of this goal and the subsequent activity of TMZ are categorically schedule dependent. Aim of the present randomized phase II study is to verify whether a treatment schedule with TMZ appropriately modified induces better response rates along with a decrease of mielotoxicity as compared to the conventional one. Methods: Twenty patients (5 F/15 M), median age of 53 years (range 35–74), median Karnofsky PS 90 (range 70–100), with GBM in progression after surgery and adjuvant RT have been treated as follows: Schedule A - TMZ for 5 days in a 28-day cycle, at the dose of 150 mg/m2/d at the first cycle and of 200 mg/m2/d thereafter, up to a total of 8 cycles. Schedule B - TMZ for 7 days alternating with 7 days of rest up to a total of 12 cycles: the starting dose of TMZ at the first ...