Efficacy of Pegamotecan (PEG-Camptothecin) in Localized or Metastatic Cancer of the Stomach or Gastroesophageal Junction

Inclusion Criteria:

* Pathologically confirmed diagnosis of adenocarcinoma of the stomach or gastroesophageal junction.
* Disease measurable in at least one dimension.
* Target tumors outside of prior radiation field(s).
* An Eastern Cooperative Oncology Group (ECOG) performance scale score of 0 or 1
* Adequate hematologic profile, as determined by hemoglobin, platelet, and neutrophil count.
* Adequate renal function, as determined by serum creatinine and serum albumin measurements.
* Adequate liver function, as determined by total bilirubin and transaminases levels. Transaminases may be \<= 5.0x ULN if due to metastatic disease in the liver.
* Fully recovered from prior surgery.
* No history of hemorrhagic cystitis.
* No microscopic hematuria (\>10 RBC/hpf) unless documented to be due to an infection or non-bladder origin.
* Capable of understanding the protocol requirements and risks and providing written informed consent.

Exclusion Criteria:

* Concurrent serious medical illness unrelated to tumor within the past 6 months.
* Known chronic infectious disease, such as AIDS or hepatitis (screening for hepatitis and HIV will not be performed).
* Positive screening pregnancy test or is breast-feeding.
* Female or male subject of reproductive capacity who is unwilling to use methods appropriate to prevent pregnancy during the course of this study.
* Receiving concurrent chemotherapy, investigational agents, radiotherapy, surgery, or has received wide field radiation within the previous 4 weeks.
* History of another malignancy (except basal and squamous cell carcinomas of the skin and carcinoma in situ of the cervix) within the last 5 years.
* Known or clinically suspected brain metastases.
* Received more than one prior regimen of chemotherapy for locally advanced or metastatic adenocarcinoma of the stomach or GE junction.
* Received prior neoadjuvant and/or adjuvant cytotoxic chemotherapy
* Received any investigational drug within the last 30 days.
* Not fully recovered from any prior, and from any reversible side effects related to the administration of cytotoxic chemotherapy, investigational agents, or radiation therapy.
* Prior treatment with a camptothecin analog.