Single-arm, open-label study of AMG 479 in up to 35 subjects with Ewing's Family Tumors (EFTs) and Desmoplastic Small Round Cell Tumors (DSRCTs) who have progressed or recurred after at least one prior chemotherapy regimen. An exploratory cohort of an additional up to 10 subjects with prior exposure to anti-IGF-1R therapy and who have progressed or recurred after at least one prior chemotherapy regimen will also be assessed.

Male and female subjects ≥ 16 years of age with a diagnosis of EFT or DSRCT who have relapsed or progressed after at least one prior chemotherapeutic regimen will be eligible for this study.

Before any study-specific procedure, the appropriate written informed consent must be obtained.

Inclusion Criteria:

Disease Related Subjects with pathological or histological diagnosis of Ewing's Family Tumor or Desmoplastic Small Round Cell Tumor.

• Measurable disease as defined by RECIST.
• Documented failure of at least one prior chemotherapy regimen for their disease.
• Eastern Cooperative Oncology Group (ECOG) Performance Status ≤ 2.

Demographic

• Males or females ≥ 16 years old.
• Signed written informed consent.
• Able to comply with visits and procedures.

Laboratory

• Willing to provide existing and/or newly acquired tumor samples.
• Diabetic Subjects (Type 1 or 2) must have HgbA1c < 8.0% and fasting blood glucose level < 160 mg/dL.

General

• Must be willing and able to use birth control (double barrier protection or abstinence) during and for 6 months after the study
• Prior exposure to another anti-IGF-1R therapy will only be allowed for a limited number of additional subjects (up to 10) in an exploratory cohort

Exclusion Criteria

Disease Related

• Known brain metastasis.
• History of bleeding diathesis.
• History of another malignancy.
• History of chronic hepatitis.
• Documented prior history of human immunodeficiency virus.

Laboratory

• Absolute neutrophil count < 1.5 x109/L.
• Platelet count < 100 x 109/L.
• Hemoglobin < 9 g/dL.
• PT > 1.5 x institutional upper limit of normal (IULN) or PTT > 1.0 x IULN.
• Serum creatinine > 1.5 x IULN.
• Aspartate aminotransferase (AST) > 2.5 x IULN or Alanine aminotransferase (ALT) > 2.5 x IULN (> 5.0 x if liver metastases present).
• Total bilirubin > 1.5 IULN (> 3.0 x with documented Gilbert's Syndrome)

Medication

• Antitumor treatment within 21 days of Study Day 1.
• Anticoagulation therapy within 28 days of Study Day 1.
• Major surgery within 28 days of Study Day 1.

General

• Other investigational procedures are excluded.
• Inability to tolerate intravenous administration.
• Subject is pregnant (eg, positive HCG test) or is breast feeding.