• To further establish the safety and tolerability of ADI- SS PEG 20,000 mw.
• To determine the clinical efficacy of ADI-SS PEG 20,000 mw in patients with advanced melanoma.

• To evaluate the metabolic activity of ADI-SS PEG 20,000 mw by [18F]-FDG PET.
• To determine the pharmacodynamics of ADI-SS PEG 20,000 mw in patients with advanced melanoma after intramuscular injections of ADI-SS PEG 20,000 mw.
• To correlate the immunogenicity of ADI-SS PEG 20,000 mw with clinical response.
• To correlate argininosuccinate synthetase (ASS) tumor expression with clinical response.

The purpose of this study is to test a new drug called ADI-SS PEG 20,000 mw in patients with melanoma. The study drug (ADI-SS PEG 20,000 mw) is being used because it causes a nutrient called arginine to break down. Arginine is an amino acid. Amino acids are the building blocks that our bodies use to make proteins. Normal cells do not require arginine. Melanoma cells, however, seem to need arginine to survive. ADI-SS PEG 20,000 mw will be used as a way to starve melanoma cells and stop them from growing.

This is a phase I/II, open-label, dose-escalation study of ADI-SS PEG 20,000 mw in patients with advanced melanoma. Eligible patients will receive ADI-SS PEG 20,000 mw intramuscularly (IM) once weekly for 9 weeks (Cycle 1). [18F]-FDG PET and CT scans will be performed at baseline and at the end of cycle 1 (week 8 and 9 respectively) for assessment of tumor response and changes in tumor metabolic activity induced by ADI-SS PEG 20,000 mw. [18F]-FDG PET will also be performed on study day 4 for assessment of tumor metabolic activity following the first dose of ADI-SS PEG 20,000 mw. Formal assessment of response by RECIST and EORTC functional criteria will be based on a comparison of conventional CT scans and [18F]-FDG PET scans done pre-treatment and at the end of Cycle 1 (week 8 and 9).

Blood samples will be obtained prior to each ADI-SS PEG 20,000 mw IM injection for plasma arginine and citrulline levels and ADI concentration analysis and detection of anti-ADI antibodies. Patients will be assessed by physical examination and laboratory studies (CBC, fibrinogen, PT/PTT, comprehensive chemistry panel, LDH, amylase, lipase and uric acid) every two weeks while undergoing treatment. A review of toxicities will be conducted during each study visit.

If a patient completes treatment in Cycle 1 without Dose limiting toxicity (DLT, then the patients will be eligible to continue to Cycle 2 starting at study week #10 if one of the following criteria is met:

1. CT shows enlargement of existing disease without accompanying symptoms.

   or

2. CT shows stable disease or improvement and there is no unacceptable toxicity.

If patient develops symptoms referable to disease progression or if CT shows new disease, then no further ADI will be given.

Radiologic evaluations will be repeated for patients treated in Cycle 2 during study weeks 16 and 17 to determine eligibility for Cycle 3. The same eligibility criteria used for Cycle 2 will apply for continuation to Cycle 3.

Phase I:

The dose levels of ADI-SS PEG 20,000mw to be administered are outlined below:

• Cohort 1 (40 IU/m2)
• Cohort 2 (80 IU/m2)
• Cohort 3 (160 IU/m2)

Phase II:

The cohort determined to be the highest tolerated dose level from Phase I will be expanded up to 25 patients.

• Metastatic Melanoma
• Skin Cancer
• Neoplasm

• Experimental: Cohort 1 dose will be 40IU/m2
• Experimental: Cohort 2 dose will be 80IU/m2
• Experimental: Cohort 3 dose will be 160 IU/m2

Inclusion Criteria:

1. Patients must have histologically confirmed malignant melanoma, AJCC stage III (unresectable) or IV. Patients with uveal and mucosal melanomas are eligible.
2. Measurable disease using RECIST criteria (Appendix 1).
3. For all patients, pathology slides must be reviewed by the Memorial Hospital Department of Pathology or NYU Department of Pathology for confirmation of melanoma diagnosis.
4. Patients must have a Karnofsky performance status of at least 80.

5. Patients must have adequate organ and marrow function as defined below:

   • WBC >3,000/microL
   • absolute neutrophil count >1,500/microL
   • platelets >100,000/microL
   • total bilirubin < 2.5X upper normal institutional limits
   • LDH <1.5 X upper normal institutional limits
   • albumin >3.0 mg/dl
   • creatinine <2.0 mg/dl
6. Expected survival of at least 3 months.
7. Age ≥ 18 years.
8. Able and willing to give valid written informed consent.

Exclusion Criteria:

1. Patients who have had chemotherapy, immunotherapy or radiotherapy within 3 weeks prior to first dosing of study agent or those who have not recovered from adverse events due to agents administered more than 3 weeks earlier. For nitrosoureas, at last six weeks must have elapsed.
2. Any other malignancy that requires concomitant therapy.
3. Any medical condition which might make it difficult for the patient to complete the full course of treatments is grounds for exclusion, at the discretion of the Principal Investigator or co-Principal Investigators.
4. Metastatic disease to the central nervous system, unless treated and stable.
5. Known HIV positivity.
6. Mental impairment that may compromise the ability to give informed consent and comply with the requirements of the study.
7. Lack of availability for clinical follow-up assessments.
8. Participation in any other clinical trial involving another investigational agent within 3 weeks prior to enrollment.
9. Pregnant women or women who are nursing are not eligible. Women of child-bearing potential and sexually active men must be using appropriate contraception during the course of this study. Women of child-bearing potential must not be pregnant (negative beta HCG within 2 weeks of treatment) nor be nursing during treatment.

• Memorial Sloan-Kettering Cancer Center
• New York University School of Medicine