Inclusion Criteria:

1. ≥18 years of age with histologically confirmed metastatic or recurrent endometrial
cancer

2. Documented progression of their endometrial cancer (i.e., within the last 3 months)

3. If of childbearing potential they must agree to use approved barrier methods of
contraception

4. Presence of at least one measurable lesion that:

- Can be accurately measured in at least one dimension with longest diameter ≥20
mm using conventional techniques or ≥10 mm with spiral CT scan (or otherwise at
least twice the reconstruction interval for CT or MRI scans).

- Previously irradiated lesions may be considered to be measurable provided: 1)
there has been documented progression of the lesion(s) since completion of
radiotherapy, and 2) the criteria for measurability as outlined above are met.

5. ECOG performance status ≤ 2

6. Minimum life expectancy of 3 months

7. Adequate renal and hepatic function (per study protocol guidelines)

8. Adequate bone marrow function (per study protocol guidelines)

9. Serum cholesterol <350 mg/dL and triglycerides < 400 mg/dL

10. Able to understand and give written informed consent

11. Ejection fraction >55% with no focal left ventricular wall motion abnormalities in
patients with a history of coronary artery disease or a history of congestive heart
failure.

Exclusion Criteria:

1. Women who are pregnant or lactating

2. Presence of brain metastases

3. Two or more prior cycles of cytotoxic chemotherapy since recurrence (Two total
regimens are allowed if one includes adjuvant therapy.)

4. Prior therapy with Trisenox or known sensitivity to this agent

5. Prior anticancer treatment (chemotherapy, radiotherapy, immunotherapy, biological
response modifiers, signal transduction inhibitors, etc) within 4 weeks prior to the
first dose of Trisenox.

6. Ongoing toxicity associated with prior anticancer therapy (except peripheral
neuropathy of ≤ grade 1 by NCI toxicity criteria)

7. Another primary malignancy within the past three years (except for non-melanoma skin
cancer and cervical carcinoma in situ)

8. Significant uncontrolled cardiovascular disease

9. Active infection requiring systemic therapy

10. Known HIV infection

11. Treatment with any investigational agent within 4 weeks prior to the first dose of
Trisenox

12. Concurrent treatment with immunosuppressive agents other than prescribed
corticosteroids

13. Inadequate recovery from any prior surgical procedure or having undergone any major
surgical procedure within 2 weeks prior to the first dose of Trisenox

14. Patients having undergone recent placement of a central venous access port will be
considered eligible if they have recovered

15. Presence of any other life-threatening illness or organ system dysfunction which, in
the opinion of the Investigator, would either compromise the patient's safety or
interfere with evaluating the safety of the study drug

16. Prolonged absolute QTc interval > 500 msec

17. Underlying conduction disease that prevents measurement of QT interval

18. History of ventricular tachycardia or any cardiac arrhythmia requiring the placement
of an automated intraventricular cardiac defibrillator.

19. Inability to discontinue therapy with class I or class III antiarrhythmic
medications.

20. Inability to discontinue drugs known to be associated with a risk for torsades de
pointes