Imetelstat Sodium in Treating Younger Patients With Relapsed or Refractory Solid Tumors

Inclusion Criteria: * Patients with any of the following tumors who have relapsed or refractory disease are eligible: * Osteosarcoma * Ewing?s sarcoma / peripheral primitive neuroectodermal tumor (PNET) * Rhabdomyosarcoma * Neuroblastoma (measurable or evaluable disease) * Hepatoblastoma * Patients must have had histologic verification of malignancy at original diagnosis or relapse * Patients must have radiographically measurable disease (with the exception of neuroblastoma) * Measurable disease is defined as the presence of at least one lesion on magnetic resonance imaging (MRI) or computed tomography (CT) scan that can be accurately measured with the longest diameter a minimum of 10 mm in at least one dimension (CT scan slice thickness no greater than 5 mm) * Note: the following do not qualify as measurable disease: * Malignant fluid collections (e.g., ascites, pleural effusions) * Bone marrow infiltration * Lesions only detected by nuclear medicine studies (e.g., bone, gallium or positron emission tomography \[PET\] scans) except as defined below for neuroblastoma * Elevated tumor markers in plasma or cerebrospinal fluid (CSF) * Previously radiated lesions that have not demonstrated clear progression post radiation * Leptomeningeal lesions that do not meet the measurements noted above * Patients with neuroblastoma who do not have measurable disease but have evaluable disease on 131I-metaiodobenzylguanidine (MIBG) scans are eligible…