title: Safety and pharmacokinetics of temozolomide using a dose-escalation, metronomic schedule in recurrent paediatric brain tumours.
abstract: The aims of this study were to determine the maximum tolerated dose (MTD), toxicity and pharmacokinetics of oral temozolomide administered over 42 d in children with recurrent/refractory brain tumours. Cohorts of 3-6 patients were treated for 42 d, followed by a 7-d rest period for a maximum of 6 cycles. Patients were stratified as heavily pre-treated (HPT) and non-heavily pre-treated (NHPT). Starting doses were 50 mg/m2 (HPT) or 75 mg/m2 (NHPT). Out of 28 patients enrolled, 20 were evaluable for toxicity and 19 for pharmacokinetics. Three patients in the NHPT group developed grade 3/4 haematological toxicity, 2 experienced dose-limiting toxicity (thrombocytopenia) at 100 mg/m2, and 9/20 developed grade 3 lymphopenia. MTD in both strata was 85 mg/m2. Responses were observed in 4 patients: 2 complete responses (CR) in medulloblastoma and supratentorial primitive neuroectodermal tumours (PNET), and 2 partial responses (PR) in high-grade glioma, respectively. Overall cumulative exposure was at least 1.5 times higher than in the 5-d administration schedule. In conclusion, the recommended dose of temozolomide is 85 mg/m2 x 42 d. Dose-limiting toxicities are thrombocytopenia and lymphopenia. The observed response rate warrants phase II studies.
authors.affiliation: New Agent and Innovative Therapy Program, Department of Paediatrics, Division of Haematology/Oncology, The Hospital for Sick Children, Toronto, Ont., Canada M5G 1X8. sylvain.baruchel@sickkids.ca
authors.forename: S
authors.initials: S
authors.lastname: Baruchel
authors.forename: M
authors.initials: M
authors.lastname: Diezi
authors.forename: D
authors.initials: D
authors.lastname: Hargrave
authors.forename: D
authors.initials: D
authors.lastname: Stempak
authors.forename: J
authors.initials: J
authors.lastname: Gammon
authors.forename: A
authors.initials: A
authors.lastname: Moghrabi
authors.forename: M J
authors.initials: MJ
authors.lastname: Coppes
authors.forename: C V
authors.initials: CV
authors.lastname: Fernandez
authors.forename: E
authors.initials: E
authors.lastname: Bouffet
mesh_terms: D000284:Administration, Oral; D018906:Antineoplastic Agents, Alkylating / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000473:pathology; D002648:Child; D003606:Dacarbazine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy* / Q000473:pathology; D000077204:Temozolomide
chemical_list: D018906:Antineoplastic Agents, Alkylating; D003606:Dacarbazine; D000077204:Temozolomide