• Patients must be 1 year of age to ≤ 30 years of age at the time of study entry.

• Patients must have had histologic verification of a solid tumor or CNS tumor at either original diagnosis or relapse.

• Measurable or evaluable disease is not required for enrollment on this safety/feasibility study.

• Patient's current disease state must be one for which there is no known curative therapy or therapy proven to prolong survival with an acceptable quality of life or for which irinotecan and/or temozolomide are acceptable therapeutic options based on existing standard of care available.

• Karnofsky Performance Status ≥ 50% for patients \> 16 years of age and Lansky Performance Status ≥ 50 for patients ≤ 16 years of age. Patients who are unable to walk because of paralysis, but who are up in a wheelchair, will be considered ambulatory for the purpose of assessing the performance score.

• Males or females of reproductive potential may not participate unless they have agreed to use an effective contraception method during and for 30 days after study treatment. (Abstinence is considered an acceptable method of effective contraception.)

• Prior treatment with temozolomide, vincristine or irinotecan is allowed, although patients must not have had disease progression while receiving either irinotecan, vincristine or temozolomide.

• Patients must have recovered from the acute toxic effects of all prior chemotherapy, immunotherapy, or radiotherapy prior to entering this study, as described below:

∙ Myelosuppressive chemotherapy: patients must not have received myelosuppressive chemotherapy within 21 days of first study treatment, but nitrosourea within 8 weeks (42 days) of first study treatment

‣ Anti-cancer agents not known to be myelosuppressive (e.g., not associated with drops in platelet or neutrophil count): must not have received these therapies within 7 days of first study treatment, or at least 5 half-lives of the agent (whichever is longer)

‣ Antibody therapy: At least 4 weeks must have elapsed since last antibody dose prior to first study treatment

‣ Radiation therapy: At least two weeks must have elapsed since last local palliative radiation (small port) prior to first study treatment. At least 6 weeks must have elapsed if more substantial radiation was administered (e.g., \>50% pelvis, craniospinal, whole body), or therapeutic radiolabeled 131I MIBG or other radiopharmaceutical therapy.

‣ High-Dose Chemotherapy with Autologous Stem Cell Transplant/Rescue: At least two months must have elapsed since receiving autologous hematopoietic stem cells prior to first study treatment. Patients who have had allogeneic transplants are ineligible.

‣ Hematopoietic growth factors: must not have been received in the 14 days prior to first study treatment for a long-acting growth factor (e.g., pegfilgrastim), or 7 days prior to first study treatment for short-acting growth factor.

• Peripheral absolute neutrophil count (ANC) ≥ 1,000/µL

⁃ Platelet count ≥100,000/µL (transfusion independent, defined as not receiving platelet transfusions within a 7-day period prior to first study treatment)

⁃ Hemoglobin ≥ 8.0 gm/dL (may receive RBC transfusions) NOTE: Patients with metastatic tumor in the bone marrow ARE eligible provided the above hematologic criteria are met.

⁃ Creatinine clearance or radioisotope GFR ≥ 70mL/min/1.73 m2 or Serum creatinine based on age/gender as follows:

⁃ Age Maximum Serum Creatinine (mg/dL) Male Female 1 to \< 2 years 0.6 0.6 2 to \< 6 years 0.8 0.8 6 to \< 10 years 1 1 10 to \< 13 years 1.2 1.2 13 to \< 16 years 1.5 1.4

⁃ ≥ 16 years 1.7 1.4

⁃ The threshold creatinine values in this Table were derived from the Schwartz formula for estimating GFR (Schwartz et al. J. Peds, 106:522, 1985) utilizing child length and stature data published by the CDC.

⁃ Bilirubin (sum of conjugated + unconjugated) ≤ 1.5 x upper limit of normal (ULN) for age

⁃ SGPT (ALT) ≤ 5 x upper limit of normal (ULN) for age

⁃ Serum albumin ≥ 2 g/dL