Recombinant Human Arginase 1 (rhArg1) in Patients With Advanced Arginine Auxotrophic Solid Tumors

Inclusion Criteria: * Confirmed diagnosis of Stage IIIb/IV malignant melanoma or castration resistant adenocarcinoma of prostate (CRPC). * Advanced cancer not candidate for treatment with modality or agents that are approved or have established efficacy. Candidates who cannot tolerate standard treatment or whose cancers have progressed on current standard of care. * Males or females 18 years-old and above. * Ability to understand and willingness to provide written informed consent; * Karnofsky performance status (see Appendix 13.3) of 80% or above and expected survival of more than 12 weeks. * Negative urine pregnancy test, if female, and willingness to use an effective method of contraception during the entire study period whether the patient is male or female. Exclusion Criteria: * Has received cancer treatment, e.g. chemotherapy, targeted biologic or enzymes, either approved or investigational, within 4 weeks prior to the start of the PEG-BCT-100; * Advancing liver failure indicated by uncontrolled ascites, pleural effusions, or encephalopathy. * Child-Pugh score of B and C (see Appendix 13.4). * Significant hepatic, renal or bone marrow dysfunction indicated by: total bilirubin \>2.0 mg/dL, evidence of bile duct obstruction, serum albumin \<2.5 g/dL, serum ALT or AST \>2.5 x upper limit of normal, serum creatinine ≥1.5 mg/dL, ANC ≥1.5 x 109/L, platelets \<100 x 109/L, or INR \>2.0. * Significant cardiac or pulmonary disease defined by New York Heart Association (NYHA) Class III or IV (see Appendix 13.5), left ventricular ejection fraction (LVEF) lower than institutional normal limits by echo or MUGA, history of myocardial infarction within the past 6 months, significant unstable arrhythmia or evidence of ischemia on ECG. * Pregnant or nursing women. NOTE: Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control or abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately. * Significant active infection including HIV requiring oral or parenteral anti-infective therapies. * Use of investigational drug(s) within 4 weeks of enrollment. * Prior treatment with arginine depleting agent.