Eribulin Mesylate in Treating Patients With Recurrent or Refractory Osteosarcoma

PRIMARY OBJECTIVES: I. To estimate the 4 month progression free survival rate and objective response rate in patients with recurrent osteosarcoma who are administered eribulin (eribulin mesylate) therapy on day 1 and day 8 of 21 day cycles. SECONDARY OBJECTIVES: I. To investigate the pharmacokinetics (PK) of eribulin in subjects with recurrent osteosarcoma. II. To further describe the tolerability of single agent eribulin. OUTLINE: Patients receive eribulin mesylate intravenously (IV) over 2-5 minutes on days 1 and 8. Courses repeat every 21 days for up to 24 months in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up annually for 5 years.