Additional Study Information: This is a Phase 1 multicenter study of a drug called ABI-009 (nab-Rapamycin) in combination withtemozolomide and irinotecan in children and young adults with solid tumors (including CNS tumors)which have come back or have not responded to standard therapy. The study is considered experimental because ABI-009 (nab-Rapamycin) is not approved by the United States (US) Food and Drug Administration (FDA) for treating children and young adults with tumors, including CNS tumors. Both temozolomide and irinotecan are drugs that are FDA-approved for other indications. The purpose of this study is to learn what kind of side effects ABI-009 given as a single agent and incombination with temozolomide and irinotecan can cause and to find the highest dose of ABI-009 that can be given safely. During Cycle 1, ABI-009 will be given as an intravenous infusion over 30 minutes on Days 1 and 8 of Cycle 1 (a cycle of therapy is 21 days). During Cycle 2 and subsequent cycles, ABI-009 will be given as an intravenous infusion over 30 minutes on Days 1 and 8 of each cycle in combination with temozolomide and irinotecan (given by mouth once daily on Days 1-5 of each cycle). Cefixime or an available equivalent antibiotic will be used to treat diarrhea during Cycle 2 and subsequent cycles. Disease assessment will be completed before beginning treatment, at the end of Cycles 1 and 2 and then every other cycle. Blood samples will be collected to determine how much ABI-009 (nab-Rapamycin) and Irinotecan is in the blood during the study (pharmacokinetics).