The purpose of the study is to demonstrate the safety and efficacy of Leuprolide Acetate for Injectable Suspension 22.5 mg in reducing serum testosterone to castrate levels in patients with prostate cancer.

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.