- This study is a companion biology study to NIH protocol 08-C-0080, A Phase II Trial of R1507, a Recombinant Human Antibody to the Insulin-Like Growth Factor-1 Receptor for the Treatment of Patients with Recurrent or Refractory Ewing s Sarcoma, Osteosarcoma, Synovial Sarcoma, Rhabdomyosarcoma and Other Sarcomas.