A Study of R1507 in Participants With Recurrent or Refractory Sarcoma

Inclusion Criteria: * progressive, recurrent or refractory Ewing's sarcoma, or recurrent or refractory osteosarcoma, synovial sarcoma, rhabdomyosarcoma, or other sarcomas of the following sub-types: alveolar soft part sarcoma, desmoplastic small round cell tumor, extraskeletal myxoid chondrosarcoma, clear cell sarcoma and myxoid liposarcoma; * Cohort 3 only: age must be \>= 2 and \<= 21 years Exclusion Criteria: * clinically significant unrelated systemic illness which would compromise the participant's ability to tolerate the investigational agent, or interfere with the study procedures or results; * known hypersensitivity to any of the components of R1507 or prior hypersensitivity reactions to monoclonal antibodies; * treatment (within the past 2 weeks) with pharmacologic doses of corticosteroids or other immunosuppressive agents; * current or prior therapy with insulin-like growth factor (IGF) inhibitor (monoclonal or specific kinase inhibitor); * history of solid organ transplant; * other malignant disease diagnosed within the previous 5 years, excluding intra-epithelial cervical neoplasia or non-melanoma skin cancer; * active central nervous system disease