Inclusion Criteria

DISEASE CHARACTERISTICS:

Inclusion criteria:

- Diagnosis of extracranial Ewing sarcoma or primitive neuroectodermal tumor of bone or
soft tissue meeting 1 of the following criteria:

- A first recurrence of localized disease

- A first recurrence of initially metastatic disease

- Disease refractory to initial conventional therapy

- Patients must have histological verification of the malignancy at original diagnosis

- Histological confirmation of relapse is highly recommended but not mandatory

- Patients must have RECIST-measurable disease documented by clinical, radiographic, or
histological criteria

- Patients who do not have measurable disease (e.g., bone scan-determined
metastatic disease only) remain eligible for the study and will be evaluable for
disease-free progression

Exclusion criteria:

- Radiological or clinical evidence for parenchymal brain metastases or neuroaxis
involvement

PATIENT CHARACTERISTICS:

Inclusion criteria:

- Karnofsky performance status (PS) 50-100% (> 16 years of age) OR Lansky PS 50-100% (≤
16 years of age )

- Life expectancy ≥ 8 weeks

- Absolute neutrophil count ≥ 1,000/μL

- Platelet count ≥ 75,000/μL* (transfusion independent)

- Hemoglobin ≥ 8.0 g/dL* (may receive RBC transfusions)

- Direct bilirubin ≤ 1.5 times upper limit of normal (ULN) for age

- ALT ≤ 5 times ULN for age

- Creatinine clearance or radioisotope GFR ≥ 70 mL/min OR serum creatinine normal for
age

- Urine protein:creatinine ratio ≤ 0.5 OR 24-hour urine protein < 1,000 mg

- Shortening fraction > 28% OR ejection fraction > 50%

- Hypertension must be well controlled on stable doses of medication for ≥ 2 weeks
prior to enrollment

- Negative pregnancy test

- Female patients who are lactating must agree to stop breast-feeding

- Sexually active patients of childbearing potential must agree to use effective
contraception NOTE: *Patients with tumor metastatic to bone marrow are permitted to
receive transfusions to maintain hemoglobin and platelet counts. These patients will
not be evaluable for hematologic toxicity. Patients who are refractory to platelet
infusions (i.e., unable to maintain platelet counts > 75,000/μL) and have marrow
involvement and platelet counts < 75,000/μL are not eligible.

Exclusion criteria:

- Documented, chronic nonhealing wound, ulcer, or significant traumatic injury (those
with bone fractures, including pathological fractures, or requiring surgical
intervention) within the past 28 days

- Other bone complications

- Deep venous thrombosis (including pulmonary embolism) within the past 3 months

- Recent (i.e., within 6 months) arterial thromboembolic events, including transient
ischemic attack or cerebrovascular accident

- History of myocardial infarction, severe or unstable angina, or peripheral vascular
disease

PRIOR CONCURRENT THERAPY:

Inclusion criteria:

- See Disease Characteristics

- Fully recovered from the acute toxic effects of all prior chemotherapy,
immunotherapy, or radiotherapy

- Recovered from any prior surgical procedure

- Prior initial therapy with topotecan hydrochloride is allowed as long as > 2 years
have elapsed since the initial diagnosis of Ewing sarcoma

- Prior therapy with cyclophosphamide or vincristine is allowed

- Minor surgical procedures (e.g., biopsies) for limited purposes of tissue retrieval
allowed

- Minor procedures include indwelling IV catheter placement and needle biopsy for
diagnostic purposes

- For minor surgeries, patients should not receive the first planned dose of
bevacizumab until the wound is healed and 7 days have elapsed

- At least 6 months since prior craniospinal radiotherapy or radiotherapy to ≥ 50% of
the pelvis

- At least 3 months since prior autologous stem cell transplantation (SCT)

- At least 6 weeks since other prior substantial bone marrow radiation

- At least 28 days since prior major surgical procedures (e.g., resection of tumor,
laparotomy, thoracotomy, or open biopsy)

- At least 2 weeks since prior myelosuppressive chemotherapy (4 weeks for nitrosoureas)

- At least 2 weeks since prior local palliative radiotherapy (e.g., small port)

- At least 1 week since prior therapy with a biologic agent or growth factor

- Patients on full-dose anticoagulants (e.g., warfarin) with PT INR > 1.5 are eligible
if both of these criteria are met:

- The patient has an in-range INR (usually between 2 and 3) on a stable dose of
oral anticoagulant or on a stable dose of low molecular weight heparin

- The patient has no active bleeding or pathological condition that carries a high
risk of bleeding (e.g., tumor involving major vessels or known varices)

Exclusion criteria:

- Prior bevacizumab

- Prior allogeneic SCT

- Radiotherapy or surgery for local control of recurrent disease concurrently with
bevacizumab (bevacizumab must be held if radiotherapy or surgery is required)

- Radiotherapy to localized painful lesions is allowed, provided ≥ 1 measurable
lesion is not irradiated

- Radiotherapy for local metastatic tumor control allowed after the first 2
courses of therapy

- Other cancer chemotherapy or immunomodulating agents

- Steroid use is allowed