• The percentage of responders who attain and maintain castrate levels of serum testosterone [ Time Frame: From Day 28 to Day 168. ] [ Designated as safety issue: No ]
  

• Demonstrate safety through all measured laboratory parameters and reported adverse events. [ Time Frame: Day 0 - Day 168 ] [ Designated as safety issue: Yes ]
  
• Characterize leuprolide serum profiles following administration study drug product. [ Time Frame: Day 0 - Day 168 ] [ Designated as safety issue: No ]
  

Drug: Leuprolide Acetate for Injectable Suspension
Sustained release injectable microspheres, 22.5 mg, one injection every 84 days, 3-month product

This study is an open-label, multi-center study in which a minimum of 165 patients will receive one (1) of three (3) lots of Oakwood Laboratories' Leuprolide Acetate for Injectable Suspension 22.5 mg for two cycles. A subset of patients (minimum of 12) will be assigned to each lot (A, B or C) and will have additional blood sampling to characterize leuprolide release kinetics for each dose administered.

Inclusion Criteria:

• Reads, understands and is able and willing to sign informed consent form
• Males greater than or equal to age 45
• Histologically and cytologically documented prostate carcinoma
• Candidate for initial hormone therapy - inclusive of patients beginning neoadjuvant or intermittent therapy, being treated locally for advanced disease, or patients beginning therapy for failure of prior local therapy
• Patients who have had prior LHRH therapy in an adjuvant or neoadjuvant setting, providing that the last date of effective therapy was greater than 6 months prior to screening
• ECOG 0-2
• Morning serum testosterone level > 150 ng/dL
• Standard screening labs within 2x ULN (AST, ALT, bilirubin and serum creatinine)
• Hemoglobin > 10 g/dL
• Life expectancy of >1yr.
• Willing to complete both cycles and all procedures of the study

Exclusion Criteria:

• Any prior (except for prior LHRH therapy in an adjuvant or neoadjuvant setting) or current definitive therapy for prostate cancer, including chemotherapy, immunotherapy, tumor-vaccines,biological response modifiers, or estrogens
• Patients who have undergone any prostatic surgery within 4 weeks of Baseline
• Patients who have undergone orchiectomy, adrenalectomy, or hypophysectomy
• Patients that are currently hospitalized or require frequent hospitalization
• Prior resistance to LHRH therapy, either neoadjuvant or adjuvant.
• Patients with evidence of spinal cord compression, ureteral obstruction or clinically significant bladder outlet obstruction
• Participation in any investigational drug, biologic, or device study within five half-lives of its physiological action or three months prior to enrollment, whichever was longer
• Patients anticipated to need concomitant hormonal, anti-androgen, radio-, chemo-, immuno- or surgical therapy for prostate cancer while on study
• History of recent drug and/or alcohol abuse within 6 months of screening
• History of HIV, HCV or HBV infection
• History of hypersensitivity or known allergy to LHRH agonists or antagonists
• Concurrent use of daily corticosteroids or other agents known to modify serum androgen within 12 weeks of screening visit
• Patients on other anti-androgens such as flutamide, nilutamide or bicalutamide
• History of other cancer with the exception of non-metastatic basal or squamous cell carcinoma of the skin
• Patients receiving any type of 5-alpha reductase inhibitor such as Proscar, Propecia, or Avodart within the past 3 months
• Patients who have experienced a myocardial infarction, unstable or uncontrolled cardiovascular disease or a coronary vascular procedure within 6 months of Baseline
• Patients who have experienced venous thrombosis within 6 months of Baseline
• Patients with other serious intercurrent illness(es) or disease(s)that might interfere with, or put them at additional risk for, their ability to receive the treatment outlined in the protocol
• Patients who have a history of the following: Immunization within 4 weeks of Baseline; Flu shots within 2 weeks of Baseline; Donation or receipt of blood or blood products within 2 months of Baseline; Anaphylaxis
• Patients who have received Oakwood's leuprolide acetate formulation previously.