The purpose of this study is to evaluate the safety and efficacy of Pegamotecan (Peg-Camptothecin) in patients with Advanced or Metastatic Soft Tissue sarcoma.

Inclusion Criteria:

• Histologically or cytologically confirmed diagnosis of soft tissue sarcoma with measurable disease.
• Target tumors outside prior radiation field(s).
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.
• Adequate hematologic profile, as determined by hemoglobin, platelet, and neutrophil count.
• Adequate renal function
• Adequate liver function
• No history of hemorrhagic cystitis or evidence of microscopic hematuria
• Capable of understanding the protocol requirements and risks and providing written informed consent.
• Either 0 or 1 prior chemotherapy regimens

Exclusion Criteria:

• Subject has a diagnosis of gastrointestinal stromal tumors.
• Concurrent serious medical illness unrelated to tumor within the past 6 months.
• Known chronic infectious disease, such as AIDS or hepatitis.
• Positive screening pregnancy test or is breast-feeding.
• A female or male subject of reproductive capacity unwilling to use methods appropriate to prevent pregnancy during the course of this study.
• Receiving concurrent chemotherapy, radiotherapy, or surgery, or has received wide field radiation within the previous 4 weeks.
• History of another active malignancy (except non-melanoma skin cancer and carcinoma in situ of the cervix), unless in complete remission and off all therapy for that disease for the last 2 years.
• Known or clinically suspected brain metastases.
• Received more than one prior treatment regimen (excluding adjuvant or neoadjuvant therapy) for soft tissue sarcoma.
• Received any investigational drug within the last 30 days.
• Not fully recovered from any prior surgery (at least 4 weeks recovery period for major surgery), and from any reversible side effects related to the administration of cytotoxic chemotherapy or radiation therapy.
• Received a prior camptothecin analog (e.g., topotecan, irinotecan).