Eligibility Criteria:
Inclusion Criteria:
* Between 1 and 30 years of age, inclusive, at the time of study entry
* Histologic verification of a solid tumor or CNS tumor at either original diagnosis or relapse. Exceptions to the requirement for biopsy include patients with primary brainstem or optic pathway tumors.
* 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.
* Karnofsky ≥ 50% for patients \> 10 years of age and Lansky ≥ 50 for patients \< 10 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. Life expectancy must be ≥ 8 weeks.
* Agreement to use an effective contraception method during and for 30 days after treatment.
* Prior treatment with vincristine, temozolomide, or irinotecan is allowed, although patients must not have had disease progression while receiving either irinotecan or temozolomide. Prior treatment with bevacizumab is not allowed.
* Adequate Bone Marrow (Peripheral ANC ≥ 750/uL, PLT ≥ 75,000/uL transfusion independent, Hgb ≥ 8.0 gm/dL), renal (negative urine dipstick for protein, OR \< 1000 mg protein/24-hour urine collection, Creatinine clearance or radioisotope GFR ≥ 70ml/min/1.73 m2), and liver function (Bilirubin ≤ 1.5 ULN, SGPT ≤ 5 ULN, Serum albumin ≥ 2 g/dL).
* Adequate blood clotting (INR, Fibrinogen, and PTT \< grade 2).
Exclusion Criteria:
* Concomitant Medications: Growth factors that support platelet or white cell number or function administered within the past 3 days, currently receiving investigational drugs, or who have received an investigational drug within the last 7 days, currently receiving other anti-cancer agents, currently taking phenobarbital, phenytoin, carbamazepine, oxcarbazepine (Trileptal), rifampin, voriconazole, itraconazole, ketoconazole or other systemically-administered azole antifungal drugs, aprepitant (Emend), or St. John's Wort, requiring antihypertensive agents at the time of enrollment, receiving medications known to inhibit platelet function or known to selectively inhibit cyclooxygenase activity, with the exception of acetaminophen.
* Require IV antibiotics at time of enrollment, or who are currently receiving treatment for Clostridium difficile infection.
* Must not have been previously diagnosed with a deep venous or arterial thrombosis (including pulmonary embolism), and must not have a known thrombophilic condition.
* Experienced arterial thromboembolic events, including transient ischemic attacks or cerebrovascular accidents, within the last year. Must not have a history of myocardial infarction, severe or unstable angina, or clinically significant peripheral vascular disease.
* Documented, chronic non-healing wound, ulcer, or bone fracture, as well as patients who have had a major surgical procedure or significant traumatic injury within 28 days prior to beginning therapy.
* Recent (within last 6 months) hemoptysis (≥ ½ teaspoon of red blood).