Temozolomide in Association With Topotecan in Refractory or Relapsed Malignant Tumors in Children and Adolescents

Long term survival can now be achieved in 75% of cases of pediatric cancers. However, some types of tumors (ie CNS tumors) or advanced stages (metastatic sarcomas/neuroblastomas) cannot be cured by any treatment. Thus, evaluation of new drugs or combinations are strongly needed. The recommended doses have been defined in children for TMZ (200 mg/m2/d x 5 d) and TPT (1.5 mg/m2/d x 5 d). Some preclinical and clinical studies have shown activity of both drugs in some pediatric cancers. Nevertheless, the association of the two drugs has never been evaluated. The study aims to determine Maximum Tolerated Dose and dose limiting toxicities of each drug when associated and to assess efficacy of the combination.

Inclusion Criteria: * histologically documented malignant tumor * refractory or relapsing after conventional treatments and for which there is no curative treatment available * life expectancy \> 8 weeks * no significant co-morbidity (NCI-CTC \< 2) * No organ toxicity * no chemotherapy within the 4 previous weeks, 6 weeks for nitrosurea or radiotherapy Exclusion Criteria: * Hypersensibility to Topotecan and/or Temozolomide or to one of their compounds * Hypersensibility to Dacarbazine (DTIC) * Galactosaemia, Glucose and galactose malabsorption syndrom, deficiency in lactase