Inclusion Criteria:

- Subject has histologically-confirmed castration-resistant prostate cancer and meets
at least 1 of the following criteria:

- subject's disease has progressed on or after available standard therapy -OR-

- there is no effective standard therapy available for treating the subject's
disease -OR-

- subject or his disease is not suitable for standard therapy -OR-

- subject chooses to defer or decline standard therapy (subject is adequately
informed of the availability of clinically meaningful therapy and chooses
instead to partake in this research using a product with no documented clinical
activity)

- Testosterone ≤ 50 ng/dL

- Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

- Life expectancy of > 6 months as evaluated and documented by the investigator

- Hematologic function, as follows (no red blood cell (RBC) or platelet transfusions
are allowed within 4 weeks of the first dose of ASG-5ME):

- Absolute neutrophil count (ANC) ≥ 1.5 x 109/L

- Platelet count ≥ 100 x 109/L

- Hemoglobin ≥ 9 g/dL

- Renal function, as follows: creatinine ≤ 1.5 x upper limit of normal (ULN), or
creatinine clearance of > 60 mL/min if serum creatinine is > 2.0 mg/dL

- Total bilirubin < 1. 5 x ULN

- Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT)≤ 1.5 x ULN

- International Normalized Ratio (INR) < 1.3 (or < 3.0 if on therapeutic
anticoagulation)

- Serum calcium ≤ ULN

- Subjects must be taking and agree to remain on a stable dose of luteinizing
hormone-releasing hormone (LHRH) agonist therapy or gonadotropin-releasing hormone
(GnRH) antagonist for the duration of the trial if not surgically castrated

- Additional Inclusion criteria for Chemotherapy Naïve Cohort: No prior systemic
cytotoxic chemotherapies

- Additional Inclusion criteria for Chemotherapy Exposed Cohort:

- Documented disease progression during or after docetaxel treatment or
intolerability to docetaxel treatment

- No additional prior chemotherapy for CRPC is allowed

Exclusion Criteria:

- History of central nervous system metastasis, including incompletely treated epidural
disease

- History of other primary malignancy (including premalignant myeloid malignancy e.g.
myelodysplastic syndrome), unless:

- Curatively resected non-melanomatous skin cancer

- Other malignancy curatively treated with no known active disease present and no
treatment administered for the last 3 years

- Active angina or Class III or IV Congestive Heart Failure (CHF) (New York Heart
Association CHF Functional Classification System) or clinically significant cardiac
disease within 12 months of study enrollment, including myocardial infarction,
unstable angina, grade 2 or greater peripheral vascular disease, congestive heart
failure, uncontrolled hypertension, or arrhythmias not controlled by outsubject
medication

- The following treatments are not allowed within 4 weeks of enrollment: cytotoxic
chemotherapy, radiation therapy or the dietary supplement PC-SPES

- Use of prednisone (or equivalent corticosteroids) > 20 mg/day are not allowed. Doses
< 20 mg/day are allowed only if they have been at the same dose for > 4 weeks

- Use of anti-androgen therapy (ie, flutamide, bicalutamide and nilutamide) within 6
weeks of study enrollment; non-responders to second-line anti-androgen therapy do not
require the 6 week withdrawal period

- Monoclonal antibody therapy within 3 months of enrollment with the exception of
denosumab (prior or concurrent use of denosumab is allowed)

- Peripheral neuropathy of ≥ grade 2 as defined by the CTCAE criteria version 4.0

- Major surgery (that requires general anesthesia) within 4 weeks of study enrollment

- Active infection requiring treatment with systemic (intravenous or oral)
anti-infectives (antibiotic, antifungal, or antiviral agent) within 72 hours of
screening

- Use of any investigational drug (including marketed drugs not approved for this
indication) within 30 days prior to enrollment

- History of thromboembolic events and bleeding disorders ≤ 3 months (e.g., deep vein
thrombosis (DVT) or pulmonary embolism (PE))

- Known positive test for human immunodeficiency virus (HIV), hepatitis C, or hepatitis
B surface antigen